022. O&M

INDEX

PAGE

I. INTRODUCTION 1

II. ENGINE 3

A. LUBRICATION SYSTEM

1 . GENERAL 32. INTERNAL CIRCULATION 33. EXTERNAL CIRCULATION 9

a. Strainerb. Pumpc. Pressure Regulatord. Thermostat Valvee. Oil Coolerf. Filtersg. Filtrationh. Standby Heateri. Monitoring & Shutdown Devices

4 . PRE & POST LUBRICATION 155. CRANKCASE BREATHER 166. OIL CONSUMPTION 177. OIL SPECIFICATIONS 188. OIL ANALYSIS 199. OIL CONTAMINATION 20

10. SYSTEM MAINTENANCE 21

B COOLING SYSTEM ••.••.••..•.........•.................••• 21

1. GENERAL 212. COOLANT 213. INTERNAL CIRCULATION 234. EXTERNAL CIRCULATION 24

a. Intercoolerb. Jacket Water Pumpco Thermostat Valved. Radiatore. Expansion Tankf. Coolant System Pipinggo Oil Coolerh. Monitoring & Shutdown Devicesi. Standby Coolant HeatersJo Standby Circulating Pumps

50 CAVITATION .... 0 0 0 0 • 0 • 0 .oo.o.oooo. 0 . 0 . 0 0 • 0 • 0 0 ••• 030

(A)

II. ENGINE (CONTO)

C. AIR-FUEL SYSTEM

PAGE

1.2 .3.

GENERAL4-CYCLENATURAL

OPERATING PRINCIPLES ~j

ASPIRATED ENGINES "G" 34

a. Air-Fuel Diagram "G"b. Fuel Pressurec. Carburetor Adjustmentd. Intake Manifold Pressuree. Starting & Loadingf. Backfiringg. Exhaust Backpressure

4. TURBOCHARGED ENGINES "GT" 40

a. Air-Fuel Diagram "GT"b. Air Inlet Pressurec. Fuel Pressured. Starting & Loadinge. Balancingf. Intake Manifold Pressure

5. TURBOCHARGED ENGINES "GTL"

a. GT vs GTLb. Air-Fuel Diagram "GTL"c. Air Butterfly Linkaged. Governore. Engine Operation "GTL"

..•...••..•••••••••• 4 7

6. TURBOCHARGED ENGINES "GTLA" 52

a. Introductionb. Air-Fuel Diagram "GTLA"c. Exhaust Manifold & Waste Gated. Cylinder Heade. Governor & Ignitionf. Starting Systemg. Engine Operation IIGTLA"

7. GTLB .8. AIR CLEANER .9. TURBOCHARGER ..

a. Maintenanceb. Turbine Housing & Nozzle Ringc. Rotor Assemblyd. Intermediate Housing & Bearingse. Blower Inlet Casing

(B)

· 59· 60· 61

C. AIR-FUEL SYSTEM (CaNTO) PAGE

10. GOVERNORS 64

a. Mechanicalb. Hydraulic

11. SYSTEM MAINTENANCE 68

D. BEDPLATE ASSEMBLY

1. GENERAL 692. BEDPLATE 693. BEARINGS 71

a. Oilflowb. Bump Checkc. Plastic Gauged. Visual Inspectione. Bearing Damage

4. CRANKSHAFT 805. TORSIONAL VIBRATION DAMPNERS 826. FLyWHEEL 827. STARTERS 83

E. CYLINDER BLOCK ASSEMBLY

1. GENERAL 852. INSTALLATION OF BLOCK TO BED 853. CYLINDER HEAD STUDS 874. MACHINE LINER FIT 875. CYLINDER LINER 87

a. Generalb. Upper Gasket & a-Ringsc. Installation

6. COVERS - Side & End 90.7. CONNECTION ROD 91

a. Generalb. Inspect ionc. Reconditioning

8. PISTON PIN 929. J;>ISTON 92

a. Generalb. Inspectionc. Reconditioningd. Pings

(C)

II

I. E. CYLINDER BLOCK ASSEMBLY (CaNTO) PAGE

10. INSTALLATION OF ROD & PISTON 9Sa. Generalb. Rod Cap Torquing

11. CAMSHAFT ASSEMBLY 96

a. Generalb. Inspectionc. Reconditioningd. Installatione. Timing

12. AUXILIARY END DRIVE 101

a. Generalb. Overspeed Governorc. Ignition System

13. VALVE TRAIN 10314. CYLINDER HEAD 105

a. Generalb. Valves, Seats & Guidesc. Springsd. Retainers & Keeperse. Lubricationf. Reconditioningg. Rocker Armh. Installation

15. STARTING SEQUENCE 112

III. COMPRESSOR 114

A. GENERAL .................•••••••.•..•................ 114

B. OPERATING PRINCIPLES .........••.••...•.................. 115

C. FRAME 118

D. CRANKSHAFT .................•......................... 122

E CONNECTING ROD 122

F CROSSHEAD GUIDE 124

G CROSSHEAD AND PIN 125

H PISTON AND ROD 127

(D)

III. COMPRESSOR (CONTD) PAGE

I. PACKING ......•.•.•.....•..•..••....••.•••••••••••.••• 130

J. CYLINDER BODY ......••....•.••..••.••.•..••.•••.•.•..•• 131

K. PLATE VALVE

1. GENERAL 1332. RECONDITIONING 13 53. RETAINER 1364. VALVE CAP ......................••............•. 137

L. UN LOADER

1 . HEAD END 1372 . VALVE 13 9

M. LUBRICATION SYSTEM

1. GENERAL 1402. PUMP & RELIEF VALVE 1413. COOLER & FILTER 141

N. FORCE FEED LUBRICATION

1. SySTEM 1422. OIL VISCOSITY 1433. OIL QUANTITY 1444. LUBRICATOR ASSEMBLy 145

O. BALANCE .......................•............•........ 146

IV. ALIGNMENT 150

A. GENERAL

1.PURPOSE 151.2. OBJECTIVE 1513 . METHODS 151

B. FOUNDATIONS _ 151

C BLOCK MOUNTING

1.GENERAL _ _ 1532.GROUTING _ _ _ _ .154

D. SKID MOUNTING

1. GROUTING .. - _ .. _ _ _ 1542.COLD ALIGNMENT 1563.FINAL ALIGNMENT __ 158

(E)

PAGE

E. HOT ALIGNMENT •............•.•......•.•....•.•••.•....• 16 c;

V. PREVENTATIVE MAINTENANCE ] .

A. PHILOSOPHy .••.......•.•..•............••.•.••.•...... 167

B. OPERATION .............................•....•.•....... 168

C. INSPECTION ...•..........•......•......••......•.•.•... 169

D. TROUBLE SHOOTING ...............•.•.......•..•.•..•..•.. 170

E. OVERHAUL ..••........................................ 170

F. MAINTENANCE COSTS .................•..........•..•..... 171

,

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(F)

INTRODUCTION

Maintenance and operation of medium speed engines and compressors is of major concern for a large majority of companiesassociated with the oil and gas industry. These concerns affectevery department of an organization and should be one of themost important issues with any engine and/or compressor application. Maintenance and operation considerations start with thephilosophies of both the supplier and user, their policies, thedesign of equipment, its application, installation and startup. If the details of these phases of a project have been properly applied it is then, and only then, that we have the opportunity to maintain and operate the equipment within the intended specifications, with the required availability and at a competitive dollars per breakhorsepower cost which will allow areasonable return on both the investment and continuing relatedcosts.

The intent of this discussion is to approach maintenanceand operation in a practical manner from the perspective of themechanic and operator, keeping in mind there are both internaland external influences which are in most cases outside hiscontrol. Our comments and recommendations are not intended tocircumvent specific information contained in instruction booksor other data furnished with the equipment.

Specifically we will cover, in detail, the maintenance,operation and alignment of Superior Gas Engines andCompressors. Comments, maintenance tips and recommendations arebased on our background with the original equipment manufacture(OEM) and Energy Dynamics, which markets Power Parts for thecomplete line of Superior Engines and Compressors. This background encompasses design, development, testing, procurement,manufacturing, shop and field service, training and solutionsto major failures. Most of our discussion will be centeredaround the Model 825, natural aspirated and turbocharged,inline and V Superior Engine and the W Series Compressors. Amajority of the principles reviewed apply to most, if not all,equipment manufactured by other OEM's which fall into thisclassification of engine and compressor.

There are three basic classifications of equipment. Firstthere is slow speed equipment. Normally slow speed equipmentwould be an engine or compressor that operates at a speed lessthan 500 rpm. Secondly, medium speed engines or compressors areunits that operate from 500 to 1000 rpm; and thirdly, highspeed units operate at a speed greater than 1000 rpm. Our discussion will cover medium speed separable engines and compressors from 600 to 2650 bhp. A separable unit is an engine andcompressor that 1S connected by a flexible coupling. In themajority of cases, the units are skid mounted and self-contained.

To further breakdown slow, medium and high speed engines;slow speed engines normally have bedded crankshafts and have ahigh weight to horsepower ratio. Medium speed engines have amoderately high weight to horsepower ratio and can either haybedded crankshafts or underslung crankshafts. High speedengines are of an automotive design and always have cranksha~cs

that are an integral part of the cylinder block (underslung)and have a very low weight to horsepower ratio.

Our discussion will be separated into three basic sections. First the Engine, maintenance and operation; secondly,Compressor maintenance and operation; and thirdly, Alignment ofthe separable engines to the compressors will be covered. Inconclusion the discussion will include general comments associated with maintenance programs and philosophy.

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ENGINE

The subject of engine maintenance and operation includes areview of the Lube Oil System, Water Cooling System, Air-FuelSystem, and Operating Principles. Next, the complete structureof the Engine will be discussed by assembling a complete unitby individual components contained in the Bedplate (Base)Assembly and the Cylinder Block Assembly.

LUBRICATION SYSTEM

GENERAL

The advantage of medium speed engine lubrication systemsis that all the components are normally self-contained, eitheron the engine itself or on the skid. The engines are tested atthe manufacturer and packaging facility so field installationof these units is quite simple when compared to the large integral type or slow speed engines that are normally block mountedwith systems that are fabricated and assembled, to a largeextent in the field. Two types of lubrication within an engineare Pressure Lubrication and Splash Lubrication. All bearingsand bushings are pressure lubricated, such as the main bearings, connecting rod bearings, camshaft bushings, rocker armbushings, etc. Splash lubricated items include piston, liner,power valve stem, valve retainers, push rods and cam followers.It is important to identify the type of lubrication within theengine because it will assist in trouble shooting a major failure, as well as, a minor problem.

It is very important for operators and mechanics to knoweach system; the components, operation and design so thatproblems can easily be identified and corrected. Obviously,each system must be properly monitored and protected with pressure gauges, thermometers, shut-downs and alarms.

INTERNAL CIRCULATION

The oil circulating system is a pressure, wet sump, withthe lube oil supply contained in the engine bed, or sump, andcirculated by means of a gear type pump which is driven fromthe crankshaft. The pump takes oil from the engine sump,through a suction strainer and inlet connection, which isdesigned to prevent formation of a vortex with possible loss ofprime, and delivers the oil to the oil cooler, then to a fullflow type filter, and finally to the lube oil manifold on theengine. Figure 1 is the cross-section of an 8G825 Engine andwill assist in the review of Internal Engine oil Circulation .

3

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FIGURE 18G825

From the lube oil manifold, located on the side ot the 2dplate, oil flows to all main bearings, then through drilledpassages in the crankshaft to the crankpin bearings, and thenthrough the rifle drilled connecting rods/to the piston pinbushings and piston cooling chamber. A line from the main oilheader feeds the rocker arms and pushrods. Other lines deliveroil to camshaft bearings, governor and accessory drives. Turbochargers are fed from a branch from the main oil header with adrain from the turbo to the engine sump.

The engine cross-sections indicate the location of theengine lube oil cooler, the filter, and the lube oil header.The upper part of the cylinder block has an internal headerthat feeds by tubing lube oil to the rocker arm-bushings anddown to the camshaft bushings. The rocker arm bushing isdrilled with two holes. The rocker arm bushing is assembledwith the small hole located toward the power valve assembly andthe large hole toward the power valve adjusting screw. The sizeof the holes in this bushing controls the amount of lubricationto each point. The rocker arm has an internal drill passagewhereby oil flows to the power valve stem, retainer and springsfor splash type lubrication. This oil flows around the pushrod,down around the cam follower assemblies to the cams.

4

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In discussions of systems, how they are designed and theirpurpose, the complete knowledge of a system is of major importance because it will be of assistance in trouble shootingfailures. It is important to note that from the lube oil header, which is the first point of lubrication in relation to thelast point of lubrication, the part that receives the highestamount of lube oil pressure will be the main bearings. Due torifle drill passages from one point to another a pressure dropwill occur within the system which results in reduced oil pressure for connecting rod bearings, and an additional pressuredrop to the connecting rod pin bushings. Due to other internalpressure drops, the pressure will slowly decrease to the farthest lube point within the system. The part that receives theleast amount of lube oil pressure will be the rocker arm bushing, because it is the farthest point from the main lube oilsupply manifold or header. In the event of loss of lube oilpressure, the point farthest away from the supply will often beaffected first. Heavily loaded parts, at the time of failure,however, normally have the greatest amount of damage. In comparison, the rocker arm bushing is not a heavily loaded itemwhen compared to the connecting rod bearing, the connecting rodbushing or the pin bushing. For these heavily loaded parts theoil supply is more critical.

Figure 2, the Longitudinal Cross-Section of the 8G825Engine indicates the gear off the crankshaft that drives theLube Oil Pump. With the cross-section, the oil circulation canbe followed from the engine main bearings, through rifle

FIGURE 28G825

5


drilled passages in the crankshaft to provide lubrication tcthe connecting rod bearing all the way up to the pin, and t~~

top of the piston. The pistons have a "cocktail shaker" COl .ngsystem. The top of the piston on the 825 series engines hasgravity flow back to the crankcase. In operation the pistonwill shake the oil in the top of this cavity and thereby provides cooling of the crown, which is the hottest part due tocombustion.

The cross-section indicates the location of the camshaftbushings which are pressure lubricated, and a cut-away of acylinder head with the power valves and stems shows lubricationunder the splash-fed system.

Figure 3, an 8GT825 Cross-Section, indicates that thisengine is the same basic design as the in-line naturally aspirated 8G825 engine with the exception that it is turbocharged.Figure 4 is the Cross-Section of a V825. Internal oil circulation of these engines are basically the same with one exception. The turbocharger is supplied oil through an external linefrom the engine lube oil header. It is normally 3/8" tubing anddue to restriction to flow the turbo will always have less oilpressure than the engine lube oil header.

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FIGURE 38GT825

6

I INTERNAL CIRCULATION

wo.TER "'--ET MMK1X.D

FIGURE 4V 825

The turbochargers on Superior engines require 30 psi oilpressure. Due to the design of the Superior Engine and the lubeoil system, it is impossible to reach this pressure. The lubeoil to the turbo is normally around 20 to 25 psi, which isslightly less than recommended, but past experience has shownthat no major failures have occurred due to this lower thandesign oil pressure.

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Figure 5 indicates a typical cut-away of an EngineConnecting Rod and Power Piston. This figure gives more detailof the connecting rod bearings and the center grooving of thebearing, whereby the main oil supply comes into the connectingrod through the crankshaft from the main bearing. Also note,how the connecting rod is rifle drilled so the oil flowsdirectly up into the center of the hollow piston pin and fromthe hollow piston pin oil flows through drilled passages in thepin, to provide lubrication to the pin bushing. The end of thepin is drilled to provide lubrication to an internal drilledpassage in the piston to the top of the piston crown and gravity flows through the piston below the pin to the crankcase orsump .

7


FIGURE 5PISTON & CONNECTING ROD

EXTERNAL CIRCULATION

Figure 6 is a diagram of the External Engine Lube OilCirculating system.

The flow of oil is through a strainer to a positive displacement gear-type pump. Excess oil is then by-passed back tothe sump through a Lube Oil Pressure Regulatini Valve whichsenses lube oil header pressure and compensates for both fixedand variable system pressure drops. The oil then goes to athermostatic valve, which by-passes the lube oil cooler whenthe oil is cold, and directs it into the cooler when the oilcomes up to temperature. From the cooler the oil is directed toa bank of individual filters and then directly to engine lubeoil manifold or header.

It is important to note that the system shown in Figure 6is of a late design. Some of the earlier Superior Engines hadthe flow of oil going from the pumps, to the filters, then fromthe filters to the cooler, and from the cooler to the lube oilheader. The concept in today's design, is to go through thecooler first and the filter second. Filters need to be located


as close to the lube oil headers as possible to minimize thepossibility of foreign particles entering the engine and components, such as the turbocharger. Lube oil System Retro-fit Kitsare available to convert existing oil design units to today'sstandard.

~--~VENT

40 PSI

LUBE OIL FILTERS

ENGINE LUBE OIL HEADER

LUBE OIL COOLER

~ 15 PSI

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PRE & POST LUBE

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FIGURE 6LUBRICATION SYSTEM

The following discussion describes each component of theLube Oil System in detail.

Strainer: Oil is pulled from the engine lube oil sumpthrough a suction strainer. All medium speed and high speedengines have suction strainers upstream of the engine lube oilpump. One purpose of the strainer is to protect the system frombeing clogged with large items which may be left in the sumpafter assembly. The second purpose of the strainer is to eliminate air from getting into the system or to eliminate a vortex,whereby air can be pulled into the engine by the lube oil pump.It is important to note the position of the strainers beforeremoving from the engines, so they can be re-assembled in thesame orientation. Some strainers have a solid sheet metal coveron top with a wire mesh screen at the bottom. This type ofdesign prevents air from getting entrained in the lube oilsystem.

9


Pump: The Lube Oil Pump is gear or chain driven off th.crankshaft; it is a positive displacement gear type pump. Trmaintenance of the Lube Oil Pump is minimum because it is slubricated. There are four bronze bushings on the pump shaftswhich should be checked periodically and at major overhauls. Animportant item to remember, upon dis-assembly of the pump, isthe capacity will vary depending on end clearance. The more endclearance, the less efficient the pump; therefore, it is important to maintain design end clearance to assure required capacity. Also, of major importance is the setting of the back lashbetween the crankshaft gear and lube oil pump drive gear.

Pressure Regulator: The system pressure is controlled bya lube oil pressure regulator, dual-point valve. The valve provides pressure relief to protect system components againstover-pressure during cold starts or any other system malfunction. The control signal to the valve is from the engine oilmanifold during normal operation. The valve maintains constantpressure under varying speed and temperature conditions. Excessoil pump capacity is automatically by-passed to the enginesump. In addition, the valve compensates for any existing pressure loss through the piping, lube oil cooler or filters.

The end plate of the lube oil pressure regulator containsthe sensing port and is tied directly to the engine oil manifold. There are two operating ports and one sensing port. Theoperating port feeds' oil supply internally to the back side 0

the piston which offsets the normal spring pressure. When trheader oil supply pressure is minimum the spring tension wil~

close the piston, restrict by-passed oil, and increase systemoil pressure. As the engine lube oil header pressure increases,the supply pressure to the sensor increases; therefore, thepressure on the back side of~the piston offsets spring pressure, moving the piston back to the normal operating mode.

The maintenance of this particular valve is primarilyassociated with cleaning and checking on a periodic basis. Thevalve should be removed, cleaned, tested, and then set. A sparevalve must ~ be of a standard relief valve design. It must beof the same design and have the same internal porting, becausethis special designed valve requires discharging up tD the complete capacity of the pump.

Thermostat Valve: Most engines have a thermostat valve.Some of the older units, however do not. The purpose of the,thermostat valve is to by-pass the engine lube oil cooler forfaster warm-ups. After the oil reaches in excess of approximately 120°F., the valve directs oil through the engine lubeoil cooler.

011 Cooler: The shell and tube lube oil coolered with large admiralty bronze tubes. Cooling water

is design(engine

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,~.. ------------------------------

!• EXTERNAL CIRCULATION - Oil Cooler

jacket water) passes through the tubes in the opposite direction of the oil flow for maximum cooling. Usually, the shellside is designed for 200 psi and the tube side 150 psi. Typical other design data is as follows:

OIL SIDE WATER SIDE

Temperature In - 200°FTemperature Out- 175°FFlow - 60 GPMPressure Drop - 9 PSI

Temperature In - 160°FTemperature Out- 162°FFlow - 375 GPMPressure Drop - 4.5 PSI

Note: It is of upmost importance to maintain approximately 15°F differential between the oil and water temperaturein order to maintain design clearance between engine components, such as the power piston and liner. In addition, it ismost desirable to maintain the inlet oil temperature at approximately 175°F and the inlet jacket water temperature at approximately 160°F.

Filters: The item which requires the most maintenancewithin the lube oil system is the filters shown in Figure 7.Depending on the operating conditions, filter elements must beperiodically changed to assure clean oil is supplied to theengine bearings and other components. Typical filter designdata is as follows:

ParticlesParticlesParticles

MicronMicronMicron

4010

5

ofofof

RemovalRemovalRemoval

Shell Design Pressure - 150 PSIMaximum Element Differential Pressure - 110 PSINormal Filter Differential Pressure - 3 PSI @ 20 GPM

& 180°F OilMicron Rating 100 %

95 %65 %

The lube oil filter elements for Superior Engines are asock type. The oil enters the filter can from the side, circulates around the element, and passes through the element to thecenter tube and out the bottom. A retaining plate at the top ofthe filter forces the filter down into the can to obtain a positive seal, top and bottom.

•

\ .Internal by-pass fllters are not recommended and should be

converted with kits which are available at nominal costs.Filters, with internal by-passes, incorporate a relief valve asa part of the upper retainer plate. When the lube oil differential pressure across this element exceeds 25 psi, the springloaded internal relief valves open, the oil will by-pass intothe top of the canister and down the center tube to the engine.The reason for changing from an internal by-pass filter to anon-internal by-pass filter is to eliminate a major source ofdirt and sludge contaminatiorl of the lube oil .

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EXTERNAL CIRCULATION - Filters

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ooe'flJl=. 1m!

FIGURE 7OIL FILTER

Normal oil flow enters the side of the can, circulatesaround the element, then passes through the element to the ~n

ter of the tube. When the oil is cold and internal by-pass _5

incorporated within the filter, the by-pass valves open and thedirection of flow of the lube oil is disrupted. Oil flows upthe side of the filter, taking with it all the particles previously removed, and then through the reiief valves and down thecenter tube to the engine. Units using this type of filter tendto have excessive bearing and bushing deterioration and failure.

It is not recommended that existing engines be convertedto a non-bypass filtering system unless other unit protectiondevices be added. Up stream of the lube oil filters, on thelatest designed system, is an external by-pass relief valve,set at 80 psi, which provides oil to the engine during coldstarts through a 200 mesh strainer. Proper inner tube designcapable of withstanding this high differential pressure isessential to prevent an element collapse that can contribute tca major bearing failure.

Anytime an engine is down, lube oil will gravity flow dowlthe center tubes in the filters, out the lube oil header intothe main bearings and back to the crankcase_ Air pockets are ithe system_ The only way air can be removed from the filters

EXTERNAL CIRCULATION - Filters

is to manually vent each filter, or install a constant ventline as indicated on the diagram. The vent line does not haveto be large. A continuously flowing, automatic vent system canbe established with an orifice fitting in top of each can andconnecting the filters together to a common header back to thecrankcase.

It is of major importance during the change of filter elements, that the quality of the oil being removed is noted andthat the sludge and foreign particles on the sides of the elements be inspected. By inspecting elements, bearing babbitt andother wear particles of the engine can be detected.

The time between element changes is directly related to anexperience factor for a particular application. Elements shouldbe changed when the differential pressure across the filter isapproximately 12 psi. In addition, when a unit is received inthe field from a packager, all the filter elements should bechanged. After the unit is operated for approximately 400hours, the elements should again be changed, no matter what thedifferential pressure indicates. Then from that point in time,filter elements should be changed about every 1,000 hours orevery two months. The important thing to watch, after a unit isin operation, is the pressure drop across the filters for aparticular application and the filter elements for identifiableforeign particles once the filters are removed.

Filtration is the process of removing suspended solidsfrom a liquid by forcing it through a porous mass such as afilter element or the filter medium. For gas engine lube oilthe filtration purpose is as follows:

1. To remove dirt particles (25-40 microns) which arelarge enough to bridge the oil film in bearings andcause rapid wear rates or possible bearing failure.

2. To remove dirt particles (5-25 microns) that would notnecessarily damage bearing but could accelerate thewear rates of more closely fitted parts such as ringsand liners or pump gears.

3. To remove very fine carbon soot particles which aremost always present in 4-cycle engines and if notremoved could cause a gradual increase in oil viscosityand a relatively short oil life.

The sock type filter element will provide longer lifebecause of a larger pore volume and greater dirt storage

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FILTRATION

potential. Pores only fill partially until the pressure drop cdifferential pressure across the filters reaches a level ofapproximately (12) PSI which then require changing the filterelements. The pressure drop should increase gradually duringnormal operation.

The objectives of good filters are to reduce engine partswear, maintain clean oil, be safe under all normal operatingconditions and operate at a reasonable cost.

Standby Heaters: Standby oil heaters are installed onengines to permit ease of starting. Heaters, also, bring theoil up to a minimum temperature for engines exposed to extremecold ambient conditions or engines required to assume heavyloading immediately after start-up.

Normally, engine crankcase heaters are utilized to simplycirculate the lube oil through the lube oil cooler with a prepost lube oil pump. A combination of both coolant and lube oilstandby pumps can be used; oil or coolant piping can be heattaped, also.

When lube oil electric heaters are used in the crankcaseit is a necessity to assure proper circulation of the oil overthe high watt density elements. Failure to circulate the oilwill result in localized cooking of the oil and may cause deterioration of the lubricant and/or a hazardous atmospherethe crankcase.

Thermostatic controls should be installed to assure bothminimum temperature and protection for over heating the lubeoil.

Monitoring & Shutdown Devices: The necessity of unit protection, by monitoring temperatures and pressures and the needof alarms and shutdowns, can not be overlooked. Located upstream of the cooler is a temperature indicator. This devicemonitors the lube oil temperature out of the engine. Downstream from the lube oil cooler is another temperature indicator, which indicates lube oil temperature into the engine. Forunit protection the lube oil system should always have a pressure indicator and shutdown device on the lube oil header. Thisdevice monitors the oil pressure going to the engine and withany interruption of the pressure, the unit should shutdown. Theshutdown device normally activates at a minimum of 15 psi.Normal pressure at the engine lube oil header is 30 to 40 psi.Based on the normal pressure it is recommended that the shutdown pressure be set at 20 psi.

PRE & POST LUBRICATION

When a running engine is shutdown, oil immediately startsto drain from the engine oil supply system through all it'sbearing clearances. While this rate of drainage is dependent onmany factors, such as bearing clearance, oil temperature andviscosity, etc., it is possible for all running bearings tobecome quite dry of lubricant. If an engine has been shutdownfor a considerable period of time, many portions of the supplysystem become filled with air rather than oil.

When the engine is re-started, under the above conditions,a small but still definite period of time will elapse beforethe engine oil pump will force all the air from the supply system and properly supply lubricant to all of the engine bearings. During this time period, even though the engine might beoperated under no-load conditions, the lack of lubrication willresult in high rate of bearing wear. For these reasons it isrecommended that engines have some provision for pre-lubrication at startup. Operation of the pre-lube pump should be continued for a time sufficient to force all air from the systemand to provide lubricant to each and every engine bearing.

In the case of automatic started equipment, where enginesmay be called on to assume load immediately after receipt of asignal from a remote point, such pre-starting lubrication isnot possible, and some other means must be provided to ensureproper bearing lubrication to minimize the possibility of highinitial bearing wear. Since a time factor is involved in theproblem, it is recommended that a similar time factor beinvolved in the solution. Periodic cyclic operation of a motoror expansion driven pre-lube pump should be used to maintain asufficiently filled system and, also, sufficient bearing surface oil film to minimize bearing wear during the time necessary for the engine pump to pick up oil and supply it to allthe engine bearings. Pre-lube operation of five minutes duration, at approximate four hour intervals, will meet these conditions satisfactorily, and it has been standard practice torecommend the installation of this type of system.

The pre-lube pump is normally connected in parallel withthe engine driven lubricating oil pump, and a check valve isinstalled in its discharge line to prevent any possibility ofbackflow through the pre-lube pump during engine operation. Thepre-lube pump itself is provided with a built-in bypass reliefvalve normally set at 50 psig, to eliminate any possibility ofover-loading its driver; the driver is normally sized to adequately power the pump when operating with cold oil at its normal relief valve setting. When installed in this manner, operation of the pre-lube pump automatically forces all trapped airfrom the engine supply system and provides a lubricating filmfor each and every engine bearing.

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PRE & POST LUBRICATION

If there is some doubt associated with the necessity ofpre-lube system, the next time an engine is started, watch llube oil pressure gauge. Verify the amount of time it take helube oil system to come up to 35 psi at the header. It is 0uvious that during this period of time, there are bearings andbushings within the engine that are operating without lubrication.

Pre & post-lube oil pumps are a necessity on turbochargedengines, since exhaust gases immediately start turning theturbo at high speeds and the bearings will be loaded withoutlubrication. without pre & post-lubrication to turbochargerbearings, a shortened bearing life and possibly a major failurewill result.

CRANKCASE BREATHER

All engines, regardless of manufacture, have some type ofcrankcase breather system. Most are vented to atmosphere. TheSuperior engine has the crankcase breather assembly mounted onthe cylinder block itself. This breather assembly contains awire mesh screen strainer. The purpose of the strainer is toremove liquid during operation. The crankcase breather assemblyis piped upstream of the turbocharger, or up stream of the carburetor on natural aspirated engines. During operation of theengine the intake vacuum will pull the fumes from the crankcase. The volume of air and oil fumes that are taken from th(crankcase can be adjusted by setting an orifice valve on th r

downstream side of the breather along with a water manometelocated on the crankcase, which measures crankcase pressure.

The crankcase breather system on Superior Engines isintended to maintain a vacuum at all times. The amount of vacuum that is recommended is zero to .5 inches water column.

The advantage of the crankcase vacuum system is:

(1) It helps prevent lube oil leaks;(2) It helps detect problems within the engine.

Anytime blow-by around the piston rings and liner is experienced, the crankcase will immediately change from a vacuum toa positive pressure. This change in pressure indicates a problem that can eventually lead to a major failure. Some customerseven install crankcase pressure shutdowns capable of sensinginches of water column positive pressure. It is mandatory thateach crankcase have a manometer so as to set the vacuum properly. Vacuum settings in excess of .5 inch of water could lead toincreased oil consumption.

16

I CRANKCASE BREATHER

The disadvantages associated with this type of crankcasebreather system is that a certain amount of oil is removed anddirected into the engine air intake system. On a turbochargedengine this oil mist will accumulate or collect on theimpeller. Any dirt or foreign particles that are broughtthrough the air cleaner system will have a tendency to collecton the turbo impeller: this has a tendency to create an unbalanced rotor assembly resulting in bearing failures. Anotherdisadvantage with this type of system, as opposed to a systemwhich maintains a positive crankcase pressure, is that a negative crankcase pressure tends to increase the severity ofcrankcase explosions. During a crankcase explosion, it is notthe first initial explosion that really causes the damage. Itis the second explosion, which results from sucking in a chargeof air into an explosive mixture that is the most severe.

Figure 2 indicates the crankcase breather assembly location on top of the cylinder block, on the flywheel end of theengine. When units are located outside and subject to coldambient temperatures, the condensate which is normally contained in the system will freeze. When freezing occurs it willresult in the crankcase changing to a positive pressure. Thiscan be prevented by insulating the line, circulating warm jacket water around the housing and/or around the I-inch connectingline \0 the air intake. Positive crankcase pressure can also bedetected by excessive oil leaks around labyrinth seals of thecrankshaft.

OIL CONSUMPTION

When discussing lube oil consumption it has been experienced that some customers refer to lube oil consumption in gallons per day. The correct units for lube oil consumption isbrake horsepower hours per gallon (BHP Hrs./Gal.) The following formula indicates the correct method of calculating oilconsumption.

BHP Hrs /Gal = BHP @Rated Speed x 24 Hrs./DayLube all Consumptlon/24 Hours

Note: When calculating lubricating oil consumption alwaysuse the full speed-full load rating of the engine.

EXAMPLE #1 Model GT825

BHP/Gal =

8 Cylinders rated at 1000 brake horsepower @ 900 rpm.Amount of lube oil consumed - 2.5 gallons/day.

1000 BHP x 24 Hrs. per Day2.5 Gallons per Day

bn

BHP/Gal. - 9600

17

OIL CONSUMPTION

EXAMPLE # 2 Model l6GT825

Rated at 2200 BHP @ 900 rpm.Amount of lube oil consumed - 5 gallons/day.

2200 BHP x 24 Hrs. per DayBHP/Gal = 5 Gallons per Day

BHP/Gal. = 10,560

The basic problem associated with oil consumption, is thefact that most people think that the larger the number the moreoil that is consumed in a given period. But when expressed correctly, the opposite is the case. In the above examples, a 1000horsepower engine operating 24 hours a day has an oil consumption of 9600 BHP-Hrs./Gal. As a rule of thumb, consumptionreadings of less than 8500 brake horsepower hours per gallonwould be of concern and associated with excessive consumptionfor Superior engines.

OIL SPECIFICATIONS

The selection of a lubricant must first be matched withthe application. Engine design, fuels and operating conditionseach have a significant effect on oil performance. When discussing lube oil specifications it is a must to first identifythe type of engine. The reason being that oil specificationcare not as critical on most naturally aspirated engines asis on turbocharged engines. The minimum qualities of an en Ielubricant is as follows:

1. viscosity at 210 0 F. S.U.S. 70-85, 100% solvent refinedbase stock, SAE 40 weight. Viscosity is the most important single property of a lube oil and is the measureof the internal friction of a lubricant or its resistance to flow. The higher the operating temperature thelower the oil viscosity resulting in less oil filmthickness.

2. The lubricant must contain adequate rust and corrosioninhibitors which are not detrimental to lead base babbitts or copper lead bearing alloys.

3. The lubricant must contain an appropriate antioxidantfor best oil life and an anti foaming agent to controlair entrainment which produces foam.

4. An effective E.P. (extreme pressure) additive must beemployed to prevent scuffing and wear of highly loadedparts. The E.P. additive forms a metallic salt filmthat acts as a solid lubricant on metal to metal contact surfaces .

•J

..'-----------------------

I

•

OIL SPECIFICATIONS

5. A balanced detergent - dispersant package is requiredfor engine cleanliness. The oil must minimize ringsticking, varnish on pistons, liners and valve stems,hard combustion chamber deposits and crankcase sludge.The detergent package prevents deposit formations athigh temperatures and the dispersant package preventsdeposit formations at low temperatures.

6. A sulphated ash content of .5% to 1% is preferred. Thebarium and calcium additives appear to give lower lubeoil consumption rates, lower liner and ring wear rates,and increased valve life. Deposit formations couldappear in the combustion chamber and turbo nozzle ringwhen over 1% sulphated ash content is used which couldinduce detonation or preignition. Wear rates couldincrease when using less than .5% sulphated ash content.

7. The lubricant must be resistant to nitration.

8. The TBN (Total Base Number) by ASTM D-664 should be 2.0as a minimum for use with sulphur free fuel. A TBN of6-12 is recommended if the fuel has any sulphur content. The TBN is an alkaline oil additive to neutralizeacids before it can cause corrosive wear in the engine.The TBN also reflects the useful reserve alkalinity oflube oil.

Most original engine manufacturers today are publishing aspecific list of approved lube oils. It is recommended thatoils used in Superior engines be either on the approved list orproven through years of trouble free operation.

OIL ANALYSIS

The recommended lube oil change period for Superiorengines is every 1,000 hours. The only way this recommendedperiod can be extended is through a lube oil analysis program.The major advantage of such a program is that it can extend theintervals between oil changes.

Obviously, another reason for the lube oil analysis program is to detect different wear rates within the engine aswell as other contaminations such as ethylene glycol. For example, iron will indicate piston and/or liner wear; copper andbrass would be associated with bearing and bushing wear; silicone associated with air inlet problems; high acid or low PHIS related to water problems, etc.

Oil analysis is a maintenance tool which should not beoverlooked. Of major importance is to become associated with areputable oil analysis firm and log the rate of change of allcontaminates .

19

, !

tI

I\

OIL CONTAMINATION

All engines have the susceptibility to become contamin<Qwith ethylene glycol, either due to leaking of gaskets orthrough major failures. Ethylene glycol contamination in sn._~l

amounts of 1 % can seriously damage engine parts. After contamination, a sludge forms throughout the engine; liners becomeglazed; rings stick and tri-metal bearings can be severelydamaged.

The lube oil should first be tested to determine thedegree of contamination. A flushing procedure using butylcellosolve is recommended to remove the ethylene glycol contamination. The type of flushing procedure that is recommended isstrictly a function of the degree of contamination.

It is not recommended that medium speed engines be runduring the flushing process to remove ethylene glycol from thelube oil. This practice is sometimes used with smaller boreengines, but since the flash point of butyl cellosolve isapproximately 155°p, serious damage can occur in large boreengines due to high operating temperatures resulting in a fire.

For contaminations below 5% the recommended procedurewould be to drain all the lube oil and install new filters. Toflush the system, use a pre-lube pump or motor driven pumpsized to pressurize'the entire system to approximately 20 psi.A valve should be installed between the main lube-oil heade'and turbocharger to obtain a pressure to the turbocharger 0'

approximately 3 pounds. Then, by using a mixture of 50% b~ 1cellosolve and 50% ten weight engine oil, flush the system at atemperature between 70 and 150 o P. Plush for approximately 1/2hour, barring the engine over slowly to allow fluid to workinto all the moving parts. Sparingly, spray the liner wallsthrough injector nozzles or spark plug holes with the flushingfluid, and flush the inner crankcase, chain drive areas,camshaft, rocker arm areas, etc. The system should be completely drained, and the filters changed; the same flushing processrepeated on all items with 60% ten-weight oil and 40% kerosene.The entire system should then be drained, the filters changed,and all main and rod bearings and crankshaft checked.

For contamination in excess of 5%, all liners should behoned and washed thoroughly with butyl cellosolve followed by akerosene rinse. It is then necessary to almost completely disassemble the engine by removing power pistons, piston rings,main bearings, turbocharger bearings, rod bearings, all powervalve parts, push rods, camshaft followers and rocker armassemblies and by washing and rinsing the same as the liners,Major items such as oil filters, oil coolers, strainers, etc.,

OIL CONTAMINATION

should be cleaned in the same manner. After assembly the lubeoil system should be flushed using the procedure described forcontamination below 5%. After running for approximately twohours, it is recommended that at least two main bearings andtwo rod bearings be removed to check and make sure that theyare operating satisfactorily. If the bearings check out okay,the engine is ready for continued operation.

SYSTEM MAINTENANCE

Maintenance of the lube oil system is required to supplythe engine parts with a good, clean, quality oil at all times.

When discussing oil systems, leaks are a common concern tomost mechanics and operators. Leaks must be minimized becauseit affects the operation of the unit and affects the attitudesof the people working on and around the unit. Historically,engines with oil leaks tend to receive no attention, are generally poorly maintained, and have below average online availability.

COOLING SYSTEM

GENERAL

Closed cooling systems are recommended for cooling thejacket water of engines. In this type of system the coolant iscontinuously re-circulated through the engine water jacketswhere heat is picked up, then directed to an external coolingsystem (radiator) where the heat is dissipated, and subsequently goes back to the engine jackets. Open cooling systems,involving continuous water make-up at the engine water inlet,or a dumping process using engine outlet water, are NOT recommended.

The conventional cooling system is a liquid type, wherethe entire engine jacket portion of the system is completelyfilled at all times during engine operation. System design andmaintenance must be such that there is no possibility ofentrained air entering the engine water jackets.

COOLANT

Water or a water-and-antifreeze mixture is most commonlyused for engine jacket coolant, although other liquid coolantsolutions of equal capability are currently available. If wateris used, it should be clean and soft, and it must be treatedwith suitable inhibitors to minimize the possibility of scaleand/or rust formation in the system. Commercial anti-freezesand pre-mixed coolants normally contain such inhibitors.

21

COOLANT

Make-up coolant, for replacement of system evaporation or lrage losses, should be similarly treated. A regular prog'ramshould be set up for checking of coolant inhibitor content andfor replacement in order to maintain the strength required forproper system protection.

The coolant must (1) provide adequate cooling to theengine which is a function of the coolant's specific heat; (2)protect against freezing; (3) give adequate boiling protection; and (4) provide corrosion protection. Water, even thoughit is an excellent coolant medium, has a high freezing point(32°F) and a low boiling point (212°F).

The freezing pointfreeze coolants is OaF.diluted with water does

for pure ethylene glycol based antiIt is only when ethylene glycol isit offer freezing protection below OaF.

As the percent by volume of ethylene glycol is dilutedfrom 100% to 60% the freezing point drops from OaF to -60°F. Asthe percent is diluted further the freezing point decreases to+32°F in approximately a straight line relationship. The recommended coolant concentration for engines is not less than 33%ethylene glycol and .not more than 60%.

The boiling point is also affected by coolant concentration. The greater the coolant concentration, the higher theboiling point. As the system is pressurized, the boiling po'is also increased. With every pound of system pressureincrease, the boiling point is raised approximately 2.5°F. Theboiling point for pure ethylene glycol is 265°F and is reducedto 212°F as the solution is diluted with water.

Corrosion protection inhibitors is a must in many parts ofthe USA due to the poor quality of the water. Corrosion buildup impairs heat transfer. A 1/16-inch build-up of corrosionscale on a cast iron part one-inch thick will result in achange of heat transfer capabilities equal to a 4.25 inch thickcast iron part. Corrosion inhibitors must be compatible withthe coolant and balanced within the system. Inhibitors preventcorrosion by forming a film on parts, acting as ion scavengersor absorbing acids in the system.

Always select a reliable water treatment specialist withexperience in treating similar engine water systems and advisethe representative the details of the engine water system thatis to be treated. Some of the details that should be discussedare:

1. Affected metals in the system.2. Operating temperatures.3. Source and quality of water.

22

COOLANT

4. Type of system. (closed, open, combination) open systems are not recommended for Superior engines and compressors.

5. Amount of make-up water required.6. When unit was installed.7. Any previous water treatment used.8. Any prior problems with corrosion or scaling.9. Engine model, RPM and BHP and type or operation. (con

tinuous or standby duty)

Upon completion of reviewing this data the water treatmentcompany will make their recommendations and should include thefollowing:

I. Any required cleaning of the system and how it shouldbe done.

2. Any required pretreatment if the quality of the wateris questionable.

3. The type of water treatment to be used and to whatlevel it should be maintained.

4. The control limits of the level of water treatment and,if required, ph, hardness, total dissolved solids,alkalinity, chlorides, sulphates, silica, etc. thatmust be held in the treated water.

5. The frequency of tests for level of water treatment andwhen water samples should be taken and analyzed.

6. What corrective actions are to be taken when the control limits are exceeded.

Coolant analysis programs vary according to particularneeds of the user and type of engine. Any good analysis programshould begin with the analysis of the water used to dilute theethylene glycol. The water used as a dilutant should not have ahardness in excess of 170 ppm or softer than 10 ppm in chloridecontent. Pre-diluted coolants are available for use with deionized water when the normal water supply is found to beunsatisfactory. Coolant samples are normally tested for ph,reserve for alkalinity and the freezing point. Normal ph rangeis not less than 7.5 and not greater than 10.5 and reserved foralkalinity between 4 and 14 mI.


Figure 1 is a cross-section of an 8G825 Superior engine.Water enters the engine through the water or coolant manifoldlocated on the exhaust side of the cylinder block. From theheader water circulates around the power cylinder liner. Thecylinder block is designed so water passages are communitive ona longitudinal basis from one liner area to another. From thecylinder liner, the water flows upward to a water jumper whichprovides coolant to the power cylinder head. The water then

23

, .,

I

iI>,


passes through the head and out the exhaust manifold. On latestyle engines the water enters the exhaust manifold throughpassages around the exhaust manifold elbows. On old styleengines, a water jumper is used between the head and exhaustmanifold. From the exhaust manifold the water flows directlyinto the thermostat valve located on top of the exhaust manifold.

The turbocharger is also water cooled from the enginejacket water system. Water enters the turbocharger through abottom connection in the intermediate housing, cools both theimpeller and turbine discharge shroud areas and discharges at atop water outlet connection. The turbocharger coolant is thenpiped directly to the thermostat valve.


Figure 8 is a diagram of the external circulation of theEngine Cooling System. Most engines have an engine driven centrifugal water pump. The first item down stream of the pump isthe engine lube oil cooler. From the engine lube oil cooler thewater flows into a common water header located on the enginecylinder block. From the engine water header the water circulates through the engine and on the down stream side of theengine the water flbws to a thermostat control valve. Anothermajor component of the system includes a water expansion ormake-up tank located above the engine or above the radiator.The make-up line is connected back to the suction side of tpump through a I-inch minimum diameter pipe. From the thermustat valve the water flows to tpe heat exchanger and then tothe pump suction.

ENGINE MOUNTED.-- - ---- - - --,I II II II II I'1 155°f 35PSI I1 LUBE OIL COOLERL -!

FIGURE 8COOLANT SYSTEM


Intercoolers: Turbocharged engines are normally equippedwith combustion air intercoolers which permit packing greaterweights of air into the cylinders and also provide a certainamount of internal cylinder cooling. Intercoolers are cooledby a separate cooling system, independent of the engine jacketsystem, in order to provide combustion air at the optimumtemperature. Engine jacket coolant may occasionally be used,however, under favorable installation and operating conditions.

Modern units are equipped with a thermostatic by-pass ofthe intercooler water to provide a minimum inlet air manifoldtemperature of 110 to 115°F. The intent of the thermostaticcontrol valve is to achieve a more stable air-fuel mixtureunder varying operating conditions. Specifically, this willprevent mis-firing of turbocharged engines under light load orunder cold ambient conditions.

Jacket Water Pump: The jacket water pump as shown in Figure 9 is normally mounted on the engine and belt driven fromthe engine crankshaft; although on occasion, particularly forlarger size engines, it may be separately mounted and independently motor driven. Mechanical shaft seal construction is preferred over packing type sealing for minimum leakage and overall maintenance simplicity. The pump is normally of a centrifugal type and must be sized to provide the flow necessary for an

IDLER

SHAFT

SNAP RING

V-BELTS

PRE-LUBRICATED

BALL BEARINGS

IDLER

SHEAVE

COVER---_....::j:~:M-U\¥~

WATERSLiNGER----~"/.4~~.JlI!=~

DRAIN

MECHANICAL WATER PUMP

SEAL ASSEM.~-1~~~W~!J==~~~~~t---SHAFT

LOCKNUT--------------------------~J1~---- IDLERADJUSTINGSCREW

FIGURE 9WATER PUMP 25

-----------------~-----_._-

i[

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I11i \

I!

EXTERNAL CIRCULATION - Jacket Water Pump

approximate 15°F maximum temperature rise across the enginewater jackets at maximum operating loading, and to develop ~e

pressure necessary for forcing this flow rate through the stem at a designed velocity.

The engine water pump requires more maintenance than thepreviously discussed lube oil pump. Even though completewater pump repair kits are available, a spare water pumpis recommended. The major items which require maintenance arethe bearings and mechanical seal. The life of the bearings isaffected primarily by improper belt tension. Too much tensionwill cause premature bearing failures.

Thermostat Valve: A thermostatic valve serves to bring theengine jacket coolant to proper temperature more rapidly forbest overall operation upon start-up, and to maintain this temperature during subsequent operation. Full-flow by-pass typethermostats, which restrict coolant flow to the external cooling system and direct the flow back to the pump inlet duringwarm-up or other less than maximum cooling requirements, mustbe used to provide positive circulation through the enginejackets at all times. Thermostat assemblies are normally enginEmounted and set at 165°F. By-pass piping is also provided onengines that are equipped with built-in water pumps; however,they may be line mounted in the external coolant piping, as orengines with motor driven coolant pumps. Thermostat assemblare built with internal temperature-sensitive impregnated w~ ..power elements of fixed temperature range and with externvapor-pressure operated diaphragm type adjustable temperaturepower elements. The internal impregnated wax element type isnormally preferred since it is of more rugged constructi~n, isrelatively insensitive to line pressure and its temperaturesetting is not readily subject to tampering. While the formerl~

popular vapor-pressure diaphragm type unit may be servicedwithout line drainage for power element replacement, the possibility of temperature setting tampering and delicate capillarytube damage have generally limited its current usage to onlyspecial applications, where it is desired to regulate coolantflow at some point remote from the temperature sensing point.

Some customers permanently remove the thermostat elementsThis is not a correct procedure since the removal of the thermostatswill affect the pressure design of the water coolingsystem. The thermostat elements are orifices to the system andif removed will increase the velocity and reduce the pressureof the water flowing through the system. The system is designefor a specific velocity-pressure, which enables the water toremove heat from internal components. Such design changesreduce the primary objective of the cooling water system.


Radiator: The jacket water heat exchanger (radiator)serves to externally dissipate the heat picked up by thecoolant in flowing through the engine jackets. It may be mounted close to the engine, on an extension of the engine supportskid or foundation block, or at some remote point that may seemmore advantageous for a particular installation.

It may be either the liquid-to-air (radiator) type or liquid-to-liquid type. The engine coolant side should be sized tohandle the full flow of the jacket coolant pump with a reasonable drop. Sufficient heat exchanger surface must be providedto dissipate all engine generated coolant heat under maximumoperating load conditions, with due consideration to the typeof coolant used in the engine and to external liquid coolant ormaximum ambient air conditions. Consideration should also begiven to possible fouling of the heat exchange surfaces withthe passage of time and to the cleanability of the surfaceswhen fouling does occur.

Unfortunately, most radiators are sized and designed foran average ambient temperature of approximately 80°F. Extremevariations in ambient temperature changes the radiator's ability to properly cool the jacket water in mid-summer at southernlocations. The ambient temperature can reach as high as 105° to110°F. This will obviously affect the engine's cooling becausethe water temperature into the engine will be significantlyincreased as well as the water coming out of the engine.

Expansion Tank: A provision must be made to permit expansion of the system coolant liquid without loss, as its temperature increases and to prevent drawing air into the system asthe liquid contracts upon decreasing temperature. Provisionmust also be made for make-up of any system liquid loss due toleakage and/or evaporation. A positive suction head pressurefor the coolant pump through a minimum sized make-up line isalso required. These functions are served through use of acoolant expansion or surge tank. The tank should be sized to atleast twice and preferably three times the thermal expansion ofall the coolant in the entire system as its temperature israised from the minimum possible installed condition to theinstallation boiling point in order to permit expansion withoutcoolant loss and for reasonable intervals between make-upadditions. The tank is normally open or vented to operate atatmospheric pressure. It should be fitted with a sight glassor liquid level gauge to permit ready observation of the amountof coolant in the tank at all times. If a cooling radiatorlS mounted adjacent to the engine and piping can be arrangedto run continuously upward from the engine water outlet to theradiator top tank, this tank may be made sufficiently large toalso serve as the expansion tank. For liquid heat exchanger orremote radiator cooled installations, a separate expansion tank

27

EXTERNAL CIRCULATION - Expansion Tank

should be mounted at an elevation at least two feet above thhighest point of any other cooling system component.

Coolant System Piping: Coolant piping should be run in themost direct possible manner between the engine and the externalheat exchanger. Pipe sizing should be at least equal to engineconnections for normal installations and even larger if thedistance between the engine and heat exchanger is appreciable.Welded piping with long radius elbows is preferable to threadedpiping to minimize flow resistance and also to minimize leakagepossibilities. Consideration should be given to providing flexibility for thermal expansion in straight runs of any significant length. All piping should be adequately supported to eliminate any possibility of loading being imposed at the engine orheat exchanger connections. Flexible connectors must be provided if the engine is mounted on vibration isolators, or if otherinstallation conditions are such that relative movements mayoccur between the piping and other coolant system components.

Anytime a hot engine is shutdown, the water will contractin the cooling process, and air pockets will form within thesystem. The most important single item associated with coolingsystems is proper venting. Unfortunately, many inexperiencedpackagers do not vent units correctly. Without vent lines theengine can experience air lock, which will cause a major failure.

Vent lines of 1/4-inch pipe or 3/B-inch tube size (Ttsize should be maintained for all installations since smallersizing will result in inadequate venting and sensitivity toplugging, and larger sizing will result in excess coolant bypassing the heat exchanger.) should be run from the enginethermostat valve and heat exchanger (radiator) connectionpoints and from all other high points in the system piping.Some customers even go to the extent of adding a vent to thewater pump casing. Multiple vent lines may be manifolded to acorrespondingly large pipe size of comparable total flow area.Vents should be run with a continuous upward slope to enter theexpansion tank at the point below the tank minimum liquidlevel, preferably at the bottom of the tank. A return line,sized for a minimum flow area of three to four times the totalflow area of all individual vent lines but never less than oneinch pipe size, should be run from the bottom of the expansiontank to the engine coolant pump inlet. Overflow and coolantmake-up connection piping should also be provided for theexpansion tank.

Valved drain connections should be provided at all lowpoints in the engine coolant piping system. Although normaloperating coolant make-up may be conveniently made directlyinto the expansion tank, provision should also be made for

I EXTERNAL CIRCULATION - Coolant System Piping

system filling at a low point In the return piping from theheat exchanger to the coolant pump. This low point should beused for initial coolant system filling or at anytime after anappreciable amount of coolant may have been drained from thesystem, in order to minimize any possibility of air locksoccurring in the vent lines.

In addition to the above minimum requirements, certainother components are regularly installed in engine cooling systems with frequency of usage sufficient to warrant their mention as follows:

Oil Cooler: Lubricating oil coolers are standard equipmentfor all engines and engine jacket coolant is used as theircooling media. The function of the cooler is to maintain a specific temperature differential between the lube oil and jacketwater. As discussed under the lube oil system, the differentialtemperature between lube oil and jacket water should be 15 to20°F. If practical, it is desirable to maintain an oil inlettemperature of 175 to 180°F and a coolent inlet temperature of155 to 165°F.

Monitoring & Shutdown Devices: At least one thermometer orother temperature indicating device should be installed in thethermostat housing or water outlet coolent piping, to permitreading of the maximum coolant temperature out of the engine.In addition, a thermometer should be placed at the engine jacket water inlet header.

Pressure gauges are also frequently installed at variouspoints in an engine cooling system piping, the most commonlocation being immediately after the coolant pump. A typicalpump discharge pressure range would be 25 to 35 psi with theengine at 900 rpm.

Temperature and pressure sensing devices are frequentlyinstalled in engine coolant systems to sense abnormal operatingconditions and send an electrical or pneumatic signal to a control panel which then may sound an alarm and/or shutdown theengine. Superior engines are equipped with a high coolant temperature shutdown device set at 205°F and located at theengine jacket water outlet. Unfortunately, most temperatureshutdown devices must be submerged in a liquid to activate.Immediately loss of flow due to a pump failure or line breakagecan result in a steam pocket being formed at the shutdowndevice location resulting in a device not activating, and theengine continuing to run until failure. To prevent such anoccurance either the coolant temperature shutdown device mustactivate with both high water temperature and steam or a pressure shutdown device be added to the pump discharge. Coolingsystems are also often equipped with a level shutdown device onthe expansion tank.

29


Standby Coolant Heaters: These devices are occasionallyinstalled in engine coolant system piping to permit easierstarting of engines exposed to extreme cold ambient conditi 3

or on engines required to assume heavy loadings immediatelyafter start-up. They are most frequently installed in such amanner that thermal flow will provide the necessary coolantcirculation for maintaining engine jacket temperature, although in certain installations motor driven pumps may be usedto provide such circulation. When coolant heaters are used,thermostatic controls should also be installed to prevent possible loss of coolant by boiling. Electric heaters are preferable over fired or other type heaters in view of their generally simpler installation and control.

Standby Circulating Pumps: Separately mounted motor drivenpumps are occasionally installed in engine coolant systems toprovide standby circulation, and to ~liminate localized boilingpossibilities if engine operation is such that frequent shutdowns may occur when the engine is operating under heavy loading. They may also be used to provide circulation of coolantthrough the engine jackets in conjunction with external heaterinstallations.

CAVITATION

One major problem-of both medium and high speed engines i~

cavitation. Cavitation is the pitting of the cylinder linerthe outside diameter and deterioration of the cylinder bloc' atthe upper and lower liner seal areas. Normally it is mostsevere at water inlet port areas of the liner and down near thelower o-ring seal area. It may also occur at various otherpoints of the liner, such as, opposite the water entrance sideof the liner.

The liner inside the cylinder block is tightly held inplace at the top by the flange area due to the head stud torquepressing the liner down into the block. The bottom part of theliner is held rigid by the o-rings. As the engine operates, itvibrates at its natural frequency. With a combination of theliner vibration and the coolant, air bubbles form on the outside of the liner and/or cylinder block. As these air bubblesburst, they empenge to the cast iron and actually eat the castiron away. Cavitation, in extreme cases, will cause small holesto form into the i.d. of the cylinder liner which results Incoolant getting into the crankcase.

The two items available for correction are: (1) changingthe frequency of the liner vibration (cylinder block design)and, (2) making a coolant change. Superior has recently redesigned the cylinder block on all in-line engines. This haschanged the vibrating frequency of the liner, but the design ofexisting cylinder blocks is fixed. The item that can be chaneis type of coolant and/or coolant pressure.

30

CAVITATION

In most cases cavitation can be isolated, to the wateravailable for coolant dilution. The successful coolant changesto reduce and/or eliminate cavitation are as follows:

(1) Increase the static pressure on the inlet to thecentrifugal coolant pump. This can be accomplishedby raising the elevation of the expansion tank.

(2) Change the inhibitor and additive package used inthe water treatment. Adding a water soluble typecutting oil to the coolant has solved several cavitation problems. The addition of 150 ppm chromatesto the coolant has also eliminated the problem inareas where this is permissible.

(3) Change the ethylene glycol dilutant to a demineralized water.

Band-aid type fixes tend to skirt the real issue and resultin increased cavitational problems elsewhere within the engine.The outside diameter of liners are often chromed, painted withepoxy and even ceramic coated. Assuming the liner cavitation iscorrected by one of these methods, the next areas that will beattacked are the upper and lower cylinder block sealing areas.

When cylinder blocks are eaten away as the result of cavitation, it is not necessary in a majority of the cases, to scrapethe cylinder block. The cylinder block can be repaired in boththe upper flange area and the o-ring area by installing availableinserts, by using thin wall 4140 inserts in both the upper andlower liner areas with 8 to 10 thousandth interference fit. Thenby machining out the flange and o-ring area, a cylinder block canbe repaired and be as good as or better than the original.Obviously, special care must be taken in the installation of theinserts and both areas have to be properly machined .

........

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FIGURE 10

FOUR CYCLEOPERATING PRINCIPLES

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AIR-FUEL SYSTEM

GENERAL

The next system in our discussion is the air-fuel system.In relation to the oil and water systems previously discussed,it is hard to decide which is the most important. If forced toa decision, the fuel system must be considered as most important due to the direct relationship to the combustion and performance of the unit. There are two basic types of engines thatwill be reviewed.

The first type of engine is the naturally aspirated modelG-825 engine, shown in Figure 1. The basic difference betweennaturally aspirated engine and turbocharged engine is that turbocharged engine forces the air into the cylinder under pressure. The fuel is also injected into the cylinder at a higherpressure, so the increased volume of the combination of air andfuel results in more horsepower. In natural aspirated engines,the air and gas is pulled into the engine by vacuum during theintake stroke of the four cycle engine. The air and fuel gasratio on natural aspirated is controlled by a mixing valve orcarburetor.

The next engine type is the turbocharged model GT-825 engine, shown in Figure 3. The turbocharger acts as an open impeller air compressor, compressing air which is discharged j

to an intercooler and then into the air intake manifold. T'amount of air going to each cylinder is controlled by a bUe ~r

fly which in turn is controlled by the governor. The air thenpasses over a gas injection valve, is mixed and then is forcedinto the power cylinder. The amount of fuel gas is also controlled by the governor through a gas metering valve. Downstream of the gas metering valve are individual balance valveslocated in each cylinder head.

4-CYCLE QPERATING PRINCIPLES

Prior to discussing the air-fuel systems in detail, itmight be helpful to review the engine operating principles.

The correct description for the type of engines under discussion is, four-stroke spark-ignition gas engine. The operating principles of this type engine dates back to the mid-1800'sand, even today, the original proposed operating principlesremain intact. Figure 10 describes the events of four strokesof 180 0 crankshaft rotation each, or 720 0 (two revolutions) ofcrankshaft rotation per cycle.

The fuel normally used for the gas engines being considered is natural gas. The fundamental equation of complete combustion for this type of engine in simplified form is:

•

4-CYCLE OPERATING PRINCIPLES

FIGURE 11AIR FUEL SYSTEM

NATURAL ASPIRATED ENGINE

I

1fQ~._----~

When one part of fuel/methane (CH4) is added to two partsof oxygen (02) and ignited toward complete combustion, the constituents of exhaust are one part carbon dioxide (C02) plustwo parts water vapor (H20). Since the combustion processes useatmospheric air and not pure oxygen, approximately 7.5 parts ofnitrogen dilutes the concentration of oxygen and usuallyappears in an unchanged form in the exhaust. This equationgives us the correct amount of air for the complete conversionof the fuel.

Since the weight of fuel (CH 4 ) is 16 and the weight of airequals 58 (Oxygen 202) + 218 (Nitrogen 7.5N2)' the relativeamounts of required air and fuel can be expressed as air-fuelratio:

Air-Fuel Ratio 58 + 21816

17 lb.lb.

airfuel

Obviously, there are many variations of the above air-fuelratio, such as a lean mixture (excess oxygen) or rich mixture(excess fuel), but in our discussion of air-fuel systems, ourgoal for complete combustion of the valuable commodity naturalgas, is to set and maintain the items under our control so asto have 17 lbs. of air (100% theoretical air) to burn eachpound of fuel. Figure 26 indicates the normal percent of theoretical air required for Superior gas engines.

33

NATURAL ASPIRATED ENGINES "G"

FIGURE 12CARBURETOR

Air-Fuel Diagram G: Figure 11 shows a typical diagram ithe air-fuel of a naturally aspirated engine. The air intake ~s

through air cleaners or air filters and the flow is through amixing valve or carburetor. The fuel gas admitted to the carburetor is controlled by a fuel gas pressure regulating valve.The purpose of the carburetor is to obtain t~ proper mixtureof air and fuel in order to obtain complete combustion or thebest possible combustion performance under the variables whichare controllable. Downstream of the carburetor is a butterflyvalve which is controlled by the governor. The purpose of thevalve is to control the amount of air and fuel flowing into theengine. The amount of air and fuel is dependent on the carburetor adjustment, rpm and load. The horsepower indication on natural aspirated engines is the value of intake manifold vacuum.

Fuel Pressure: The amount of fuel pressure to the carburetor and to the engine is dependent on the quality of thefuel gas. The higher the BTU content, the less fuel pressurerequired to maintain the required horsepower. The lower the BTUcontent, the more fuel pressure and more volume required. Inextreme circumstances, where very high BTU gas is used, it isnecessary to change pistons in order to reduce the compressionratio. Pistons are available for Superior turbocharged and naturally aspirated engines from 10:1 down to 7:1 compression

34

NATURAL ASPIRATED ENGINES "G" - Fuel Pressure

ratio. Small deviations from a normal BTU content of 1000 maybe compensated for by adjustment of the carburetor.

The amount of fuel supply pressure to the regulator onnatural aspirated engines is normally 15 to 30 psi. The fuelgas regulator operates off of a vacuum. The greater the vacuumin the engine manifold, the lighter the load on the engine; andthe more load you have on the engine, the more fuel required,so the regulator opens.

The fuel gas regulating valve assembly for natural aspirated engines is located between the manual shut-off valve andthe carburetor. An automatic shut-off tied to the shutdown system is also located upstream of the carburetor. To obtain morefuel gas pressure on the downstream side of the regulator, theadjusting screw is turned clockwise to increase spring tensionon the upper part of the diaphragm. The bottom portion of thediaphragm senses downstream gas pressure and strokes the valveto maintain the required pressure. The top side of thediaphragm has atmospheric pressure on it and a vent in case thediaphragm is ruptured. The vent needs to be piped to a non-hazardous location, especially if the engine is located inside abuilding.

With the carburetor properly adjusted, the fuel regulatorshould be set with the engine running at zero load and ratedspeed. By turning the adjusting screw, the fuel gas pressure tothe carburetor is to be set at 4-inches of water column on allnatural aspirated Superior engines.

Carburetor Adjustment: Late model 825 engines have Impcocarburetors as shown in Figure 12, whereas older models areequipped with Ensign carburetors. Since Ensign units are nolonger manufactured, conversion kits are available with adapters to convert to the new design. Repair kits are also readilyavailable for Impco carburetors.

The carburetor downstream mixture is adjusted by Screw "A"in Figure 12. Insufficient fuel gas pressure is indicative of arequirement to turn the adjustment screw in excess of two fullturns. If during the adjustment the manifold vacuum changessignificantly with one-quarter turn of the adjusting screw, itindicates there is too much fuel supply pressure. The amount ofvacuum on the inlet manifold is measured with a manometer orvacuum gauge graduated in inches of mercury. On engines withdouble manifolds, two air inlet manifold pressure devices arerequired.

The Impco carburetor is of a very simple design and isused by most OEM's for natural aspirated engines. The air inlethousing is either on the bottom or side depending on the designor model. Opposite the gas entrance side is the adjusting

35

NATURAL ASPIR~TED ENGINES "G" - Carburetor Adjustment

screw whereby the air-fuel mixture is adjusted under a loade~

condition. The carburetor operates off of a vacuum. There alposit~ve seal diaphragms on the gas inlet and once the engjstarts cranking, the vacuum on the suction stroke will open ~he

diaphragm control valves. As the horse power requirementincreases, the vacuum on the downstream side of the carburetorreduces and the diaphragm control valves open to admit additional fuel gas.

Over a period of time the diaphragms will fatigue or possibly burst due to backfiring in the engine. The first indication of ruptured diaphragms would be shut valves resulting ininsufficient fuel supply. Most carburetors have a self-contained butterfly valve to control the discharge volume comingout of the carburetor to the engine. This valve is not used onSuperior engines and it is normally removed or blocked in thefull open position. The position of the air butterfly valve isindicated by a slot that is cut on the end of the shaft. Theslot is directly in line with the position of the butterflyvalve.

With the engine operating at rated load and speed, thecarburetor should be adjusted to attain maximum manifold vacuum. The following outlines carburetor adjustment tips which aremost commonly asked:·

(1) For better fuel consumption obtain a slightlylean mixture by adjusting Screw "A" in, untilthe manifold vacuum decreases one-half inch.

(2) For additional horsepower adjust carburetor toslightly rich mixture by turning Screw "A" out.

(3) To stop detonation, richen the mixture.

Intake Manifold Pressure: Proper air-fuel adjustment ofnatural aspirated engines is unit balance, or balance of loading. The first consideration on 825 engines is whether the unithas 6, 8, 12 or 16 cylinders. These engines have different numbers of inlet manifolds. An important item to remember is thateach manifold has its own butterfly valve which is controlledby the governor. A monitoring device to measure the vacuum oneach manifold is required on the downstream of each butterflyvalve. Each manifold must be in balance at all times becausemanifold vacuum is directly related to load. When one manifoldoperates at a lower vacuum than another, it is an indication ofmore load or an unbalance~ condition.

There are four separate manifolds on naturally aspirated vengines. Each manifold has its own butterfly valve which iscontrolled by the governor to control engine speed. When monitoring manifold vacuum or load on the engine, it is stressedthat each and every manifold be monitored. Individually

~~~---.,--------------------~d\QJlllilkti Uh4glMtMME

b

NATURAL ASPIRATED ENGINES "G" - Intake Manifold Pressure

connected mercury manometer/vacuum gauges or a single manometer/vacuum gauge may be connected through tubing with a valveto switch from one manifold to the other to obtain the requiredreadings. In other words, on a VG825, we need the capability oftaking air inlet manifold pressure at four specific points, twoon each side.

The 8G825 engine has two separate manifolds and two separate butterfly valves. The manifold appears to be a commonheader but there is actually an upper butterfly that controlsair-fuel to the four outside cylinders and a lower butterflythat controls air-fuel to the four inner cylinders. It isimportant to monitor both sections of this manifold, also.

In setting up the G825 butterfly valve linkage, the governor should be in the zero position when both butterfly valvesare closed. In disassembling the linkage, disconnect the innershaft and link between the two butterflies. Make sure both butterfly valves are closed and the inner connecting link can bereconnected without repositioning the butterfly. Both valvesmust close at the same time. By setting the valves or valve tocompletely close,the governor has the capability of shuttingthe air and fuel off, killing the engine. The engine has safetyshutdown devices, so it is not normally a requirement for thegovernor to shut the unit down, but if the linkage is properlyset it offers additional protection.

If after starting a vacuum,difference is noticed betweenthe manifolds, first make sure that both butterfly valves areinitially closed. If both valves are closed at the zero governor position then it indicates that possibly a power cylinderis not performing properly. If all power cylinders are up todesign performance, then, and only then, can an adjustment bemade to the butterfly position.

Starting & Loading: When an engine is started and at anidle, no load condition, keep in mind that the governor issensing speed and is only trying to maintain speed. The .butterfly valve is in the near closed position because the amount offuel and air that it takes to operate the engine at idle or noload condition is minimum. The vacuum downstream of the butterfly valve under this condition is maximum, because of the pressure drop across the butterfly valve. In addition, the powerpiston on the intake stroke is attempting to pull in a givenvolume of air and gas. In an idle speed and no load, a normalmanifold vacuum is approximately 16 to 18 inches of mercury.

After the engine is loaded to a minimum of 50 percent ofrated horsepower, final balance of the carburetor can be madeby setting the adjusting screw as discussed under ·Carburetor"above. To obtain proper adjustment of the air and fuel mixture,

37

NATURAL ASPIRATED ENGINES "G" - Starting & Loading

with the engine 50% loaded, increase or decrease the amountfuel to obtain the maximum amount of intake manifold vacuum..,sload is applied to the engine the manifold vacuum decreases.When load is applied to the engine, the governor has to maintain speed by opening the butterfly valve and admit more airand fuel to the intake manifold. Consequently, the vacuum isdecreased in the air inlet manifold. The maximum amount of loadon natural aspirated engines of this type is red-lined at 4inches of mercury manifold vacuum. Vacuum below 4-inches ofmercury is an indication of an overload condition or indicationthat there might be an unbalance in the manifolds creating anoverload condition of the power cylinder serviced by the particular manifold that is being monitored. One very importantitem and oversight on engines of this type is overload on anindividual power cylinder or a section of cylinders. A lot ofoperators determine load on an engine by looking at load on thegenerator set or looking at suction and discharge pressuresacross the compressor without any regard to the engine intakemanifold vacuum or from an exhaust temperature standpoint.

Keep in mind that most 8G825 engines are rated at 800horsepower. Each cylinder, in order to maintain horsepower, hasto be able to pull 100 horsepower. If a sparkplug fails 100horsepower has to be distributed with the remaining sevencylinders and it might not be necessarily distributed equallyOne cylinder might pick up 50 of that horsepower, and the or'six cylinders might equally carry the additional 50. This i 1

prime example of what happens everyday to cause scored pistons,scored liners and excessively worn parts. It becomes more of aproblem on a 6G825 when there is only five other power cylinders to pick-up the horsepower.

Anytime a power cylinder is not performing properly thegovernor will open up more because it has sensed a decreasingspeed. The governor opening admits more air-fuel and the additional load will be carried by the remaining cylinders. Thenext thing that happens is that the compression rings relax onthe power cylinder carrying no load because they are no longerheld against the cylinder wall by firing pressures and lube oilconsumption increases. The next thing that happens, is theintake air and fuel is unburned (foul spark plug situation).The exhaust temperature is decreased because of the unburnedgases passing in the exhaust manifold. The manifold is hot dueto the exhaust gases from the remaining cylinders and couldignite the unburned gases in the exhaust manifold and/or theexhaust pipe.

The more load that is applied to power cylinder, the hotter the exhaust temperatures, due to the increase in volume ofair and fuel that is being burned. The end result is that themaximum exhaust temperature of 12S0°F. is reached and a majofailure is eminent.

NATURAL ASPIRATED ENGINES "G"

Backfiring: Backfiring occurs when the combustion mixturedownstream of the carburetor is exposed to some form of ignition. For example, backfiring can occur if an intake is crackedor pre-ignited. The ignited fuel inside the cylinder escapesback into the intake manifold and then ignites all of the airand fuel that has been mixed downstream of the carburetor.Backfiring is more pronounced on a naturally aspirated enginebecause the intake manifold and all the intake piping arefilled with a combustible mixture. Backfiring is not common onturbocharged engines because the only combustible air and fuelavailable is the small volume downstream of the gas injectionvalve and the inlet power valve.

Exhaust Backpressure: The exhaust backpressure downstreamof the exhaust manifold on natural aspirated engines and downstream of the turbocharger on turbocharged engines should notexceed 12-inches of water. If the 12-inches are exceeded then itis an indication that the muffler is improperly sized, and itcan have detrimental effect on the complete combustion process.

•

EXHAUSTMANIFOLD

FIGURE 13AIR FUEL SYSTEM

TURBOCHARGED ENGINE

GOVFHNOH

39

TURBOCHARGED ENGINES "GT"

Air-Fuel Diagram GT: A typical air-fuel diagram for turbocharged engines is shown in Figure 13. After the air is ftered it is compressed by the turbocharger impeller which i_driven by exhaust gas passing through a turbine wheel. The heatof compression is then extracted by an intercooler. The airnext enters the intake manifold which supplies air to eachpower cylinder.

Figure 13 shows the cross-section of an individual cylinder. Each power cylinder on GT model engines is equipped withindividual air butterfly valves which control the volume of airthrough a. linkage connected to the governor.

Fuel gas pressure is supplied at 35 to 50 psig through amanual shut-off valve to the gas regulator. The gas regulatoror ratio regulator senses air manifold pressure and accordinglyadjusts the downstream fuel pressure. After passing through ashut-down valve the gas then enters a fuel metering valve.

Each power cylinder (GT model) is also equipped with individual fuel gas balancing valves. These valves can be manually adjusted after the engine is loaded. The fuel is thenadmitted through gas valves which are a part of the head assembly. The air-fuel is .mixed and enters the cylinder around theinlet power valve.

After combustion the products are pushed out of the cylider through the exhaust power valve during the exhaust stro:The exhaust gases are then directed to the turbocharger by wayof an exhaust manifold, which is common to all power cylinders.

After pre-setting linkage shown in Figure 14 and balancing, the air-fuel system for turbocharged engines is controlledby a duel system: the regulator and the governor. Sensing airintake manifold pressure the gas regulator increases or reducesthe available fuel gas pressure in direct proportion to changesin manifold pressure. The second control device is the governorwhich only senses speed. As speed increases or decreases thegovernor through linkage opens or closes the gas metering valveand air butterfly valves to admit more fuel and air to the combustion chambers.

In a series arrangement of controls used on "GT" and "SGT"model engines, there is the possibility that the two controlswill fight each other resulting in an unstable system. The onlyassurance of stability is to make sure that al~ system controlsare properly set. By adjusting the fuel gas regulator, the governor and the position of the butterfly valves and meteringvalve through a simple linkage, the system will control boththe air and fuel to obtain optimum performance.

;

~~~---_.......---------------~

TURBOCHARGED ENGINES "GT" - Air Fuel Diagram

FIGURE 14

LINKAGE

The control linkage setting on V engines is more criticalthan on inline engines due to the fact that there are two intake manifolds. one for each bank. System stability and performance is dependent on making sure the air butterflies andthe two gas metering valves are set exactly the same on bothbanks.

After the initial system set-up and making sure that thecomponents function properly during varying conditions, thesystem will do an excellent job of controlling the air-fuelratio. In truth the system is quite simple when compared to thesophisticated controls on some slow speed integral engines withturbocharger waste gates and controls which make adjustmentsbased on ambient temperature changes.

Air Inlet Temperature: The simplicity of the system is anadvantage in some cases but can be a distinct disadvantage inareas such as controlling air inlet temperature. Ideally, theair intake manifold temperature on turbocharged Superiorengines should be between 110 0 and 115°F. This range can easilybe attained with cold ambient conditions but, In manycases,uncontrollable during summer months with ambient temperatures in excess of 100°F.

41

TURBOCHARGED ENGINES "GT" - Air Inlet Temperature

Newer model engines are piped with a thermostat by-passvalve around the intercooler. Under cool ambient conditions tll~

valve by-passes intercooler water and maintains an air manifoldtemperature of a minimum of lOO°F. This control prevents misfiring of the engine under light loads and during periods ofcold air temperatures. Since the pounds of air entering thecombustion chamber are directly related to air temperature, thethermostat by-pass valve assists in achieving a more stableair-fuel mixture under varying operating conditions.

For units not equipped with intercooler by-pass and underhigh ambient conditions, all that can be done is to re-adjustthe air butterfly valves. During continuous, extreme hot orcold temperatures, the butterfly valves may be adjusted to beslightly more open or closed than normal. The word "extreme" isto be stressed, because it is not the intent to have operatorscontinuously adjusting butterfly valves to obtain the correctair-fuel ratio.

The engines ability to maintain a given speed and to pullthe required load is totally dependent on the operation of thegovernor. Assume the butterfly valves and the gas meteringvalve, or valves, have been adjusted for 80°F intake air manifold temperature; th~n without anybody being at the plant location, assume that the intake manifold temperature increasessignificantly. The first sign of a problem is the power, resulting from combustion, decreases. When the power of combustion decreases the governor will open and admit more fueland air to maintain the set speed.

When the governor calls for more air and fuel, both volumes increase proportionally. But under high air inlet temperatures there are less pounds of air available. So, the more gasthat is admitted the richer the mixture becomes resulting in ahotter firing temperature and the engine could start detonating. The pressures of detonation are extremely high, resultingin lifting heads enough to break firing ring or head gaskets,breaking pistons or cracking heads. ~

Now assume the air-fuel system was adjusted during thehottest time of the day and at night it cools down to SO°F. Theengine operates too lean (units not equipped with intercoolerby-pass). The governor senses a decrease in speed and theengine can not carry the load because the air-fuel mixture isnot correct. The unit has plenty of fuel gas but too much air.In addition, with extreme temperature differentials between theair and fuel, liquids can be knocked out of the fuel gasbecause of a quick change in temperature.

TURBOCHARGED ENGINES "GT"

Fuel Pressure: The fuel supply on a GT turbocharged engineshould be 35 to 50 psig. Obviously the pressure is also dependent on the quality of the fuel gas. The higher the fuel gasheating value the less volume required so less pressure isrequired. Fuels with low heating value or high elevations mayrequire a slightly higher fuel gas pressure.

If only a poor quality of fuel gas is available, then thefact must be faced from day one. The same applies to a wet orhigh BTU fuel gas. If these facts are known, then adjustmentscan be made in the operation of the engine to allow the bestpossible performance. In an extreme situation low compressionpistons can be installed, ignition timing changed or even achange in power valve timing. In all cases, the fuel gas mustbe dry. Fuel filters should be installed if there is any doubtabout liquids.

The main supply fuel pressure is controlled by a gas regulator or ratio regulator which feeds the gas to the meteringvalve. This pressure controller is a double diaphragm typevalve. The upper diaphragm has a sensing line that is tieddirectly to the intake manifold. As the manifold pressurechanges, the fuel gas pressure is increased proportionately.

NOTE: (1) Improper setting of the fuel gas regulatoror low gas supply pressure will cause the engineto run lean resulting in missing. The first thingnormally checked is ignition when a cylinder isnot firing, but often the true cause is too leanof a mixture.(2) Cold air temperatures may result in only 2 to3 psig pressure drop across the fuel gas regulator.This is normal. Summer time temperatures willincrease the pressure drop across the regulatorand automatically open the governor.

Starting & Loading: With the unit down, the steps requiredto set the air-fuel controls on GT turbocharged engines is outlined below. It is assumed that the unit is in good operatingcondition (new or recently overhauled); ignition is okay; valvetiming is correct; governor reconditioned; etc.

(1) Make sure the linkage is set in accordance with thediagram. A typical diagram for an BGT engine 1S

shown in Figure 14.(2) With the engine shutdown and the governor in the off

or zero position set the gas metering valve to readzero when closed against a .020 to .030 wire tag.1'his will result in the gas metering valve beingslightly open with the governor lever at zero.

43

TURBOCHARGED ENGINES "GT" - Starting & Loading

(3) Set the butterfly valves to be 4° to 5° open.(4) Loosen the lock screw and completely close each

balance valve. Pre-set all gas balance valves for7-1/2 turns open.

(5) Start the engine; let it warm-up and then load theunit to full rated horsepower at designed rpm.

(6) Check the gas supply pressure and set it at 35 psig.Fuels with low heating valves or units at high elevations may require a gas supply pressure in excessof 40 psig.

(7) Adjust the fuel gas ratio regulator for an averagepower cylinder exhaust temperature of 1050°F. Atypical spread of temperature for an 8GT is shownin Figure 15.

(8) Make sure that the gas header pressure is the sameon both banks of V engines.

Balancing: After the exhaust temperatures are recorded,the next step is to improve cylinder balance by adjusting theindividual balance valves (with the engine at full load). Thebalance valves are used to balance the exhaust temperaturespread. In review of the cylinder temperatures, if the majorityof the cylinders are running hot, then the next thing to do isopen the butterfly to increase the amount of air to cool theoverall engine down. Once the overall temperature is down, thenthe low temperatures can be increased by adjusting the balanc

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FIGURE 158GT EXHAUST TEMPERATURES

TURBOCHARGED ENGINES "GT" - Balancing

valves to the high cylinders. Some common sense is required,because if only one cylinder is high, the temperature of thatparticular cylinder must be immediately reduced or it will gointo detonation. If all cylinders are below the 1050°F average,then the air can be reduced.

Normally, the exhaust temperature spread will be as typically exemplified in Figure 15 and it is not necessary toadjust the butterfly valve. Therefore, turbocharged engines cannormally be balanced by only adjusting the gas balance valves.

At this point it might be well to point out that continuedreduction in fuel gas pressure can cause problems. Each timethe amount of fuel going to a given cylinder is reduced thefirst thing experienced is a decrease in speed. The governorthen opens up more to maintain proper speed to distribute thatload to the other cylinders. Continuing to decrease the amountof fuel going to the high cylinders eventually results in running out of governor travel. The end analysis is an engine thatis not capable of pulling full load at rated speed.

with above background completed the following balancesteps can be applied after Step 8, which was discussed underStarting and Loading.

(9) It should not be necessary to adjust more than 3 to 4balance valves on a 6 or 8 GT or any individual bankof a 12 or 16 VGT. Typical adjustments on an 8 or16 cylinder engine are to open #1 and #8 balancevalves 11/2 turns and close #5 cylinder 1 turn.

(10) It should not be necessary to turn any gas balancevalve more than ± 2 turns from the pre-set point of71/2 turns open.

(11) On V engines, adjust the gas metering valve linkageand/or butterfly linkage as required to maintain theclosest possible gas header and air butterfly settingon both banks.

(12) It is necessary to set the gas balance valves so asto operate on a rich enough mixture to maintainstable operation. Examples of an engine operatingon too lean mixtures are missing, governor hunt andsurge.

(13) with the balance valves on each cylinder set correctly, the next adjustment that must be made is the gasadmission valve. After checking,chances are good thegas admission valve clearance in the hot conditionwill vary from .005 to .010 inches. On this examplethe valve will open more and admit too much gas during the injection valve stroke. The gas admissionvalve clearance should be set at .013 inch HOT.

45

TURBOCHARGED ENGINES "GT" - Balancing

The following are recommended tips and a quick review ofTurbocharged engines Air-fuel systems:

A. Normal exhaust temperature is 1050°F. (Max. 1175°F.)B. Always try to run slightly lean.C. Lean out the air-fuel mixture to get out of detonation.D. Richen mixture to prevent missing.

Intake Manifold Pressure: The most common way to measurehorsepower on a Superior turbocharged engine is by intake manifold pressure. All units should have a manifold pressure gaugeor monitor.

Figure 16 indicates relationship between horsepower andmanifold pressure for a GT engine. One of the major problems istrying to load units to maximum horsepower with speeds lessthan design. Note that in this example, at rated 900 rpm themaximum horsepower is 2200 BHP, which corresponds to a positivepressure of 22-inches of mercury. At the reduced speed of 600rpm the maximum horsepower is 1000 BHP and 12-inches mercury.The engine would be considerably overloaded if it attempted topull a 22-inch manifold pressure at 600 rpm.

24

20

':t 16.

z12

If)If)

wg: 8

o-loLL 4

~

MAX

MAX

900 RPM

600 RPM

400 800 1200 1600 2000 2400 2800HORSEPOWER

FIGURE 1616 GT MAX. HORSEPOWER

TURBOCHARGED ENGINES "GTL"

GT vs. GTL: The modern version of the model GT Superiorengine is the GTL. (The "L" stands for low compression pistons.) Improvements over the GT design is worth reviewing indetail since major changes have been made in air-fuel controls(See Figure 17) in fuel consumption, and in reduced enginestress levels.

(1) Pistons - New pistons are 8-3/4:1 compression ratiovs. the old design of 10:1 ratio. This design changereduced peak firing pressure by 20%. The enginerated horsepower is maintained through controllingthe firing pressure level and duration.

AIR CLEANER

INTERCOOLER

50 PSIGFUELREGULATOR

.....--1---1-1 AI RACTUATOP.

METERING

j"'" oc~===~

-

CYLI NDER HEAD

>

TURBOCHARGER

EXHAUST/\AN IFOLD

e-XHAUST

FIGURE 17AIR FUEL SYSTEM GTL

47


(2) Camshaft - New cam timing and cam profiles provide a6% improvement in fuel consumption (to 7250BTU/BHP/HR) plus optimized valve overlap forscavenging air-fuel mixing.

(3) Turbocharger - New engines have higher flow constantpressure turbochargers. Older pulse type turbochargers may be converted for higher flow by changingnozzle rings, diffusers and, in some cases, rotorassemblies.

(4) Cylinder Block - New engines have are-designedcylinder block, which incorporates lower stresslevels in the camshaft bushing bore area and 2-1/4"vs. 2-1/8" diameter shaft.

(5) Air-Fuel System - The individual butterfly valves foreach cylinder have been replaced with fixed deflectors, and a single butterfly valve in the intake manifold is controlled by an air cylinder rather than amechanical linkage off the governor. The butterflyvalve is positioned based on fuel gas pressure withimproved control over the entire speed and loadrange. The individual gas balancing valves werereplaced with fixed orifices so the balancing procedure discussed previously is greatly simplified. Thesystem is adjusted by only two settings from a newair-fuel panel, incorporating all necessary controls.

(6) Starting System - The fuel gas ratio regulator (showndiagrammatically in Figure 17) is replaced with anactuator/diaphragmed block/vent main and start valvesystem shown in Figure 18. At a signal of 6 psi thevent closes and at 13 to 20 psi the main valve operates from the fully closed to the fully opened position.

Starting fuel gas is supplied around the main blockand vent valve through a start valve which is anactuator and equal percentage flow control device.The valve is set to operate from closed to open witha ramp pressure signal of 5 to 15 psi.

All old 8GT model engines can be converted with an available low compression kit to take advantage of the above improvements. The changes required lend themselves well to incorporating the conversion with a planned overhaul.

48

TURBOCHARGED ENGINES "GTL" - Starting System

VENT .1_-"3-'-'/8"-"__....

112"

2·"35-40 PSI FUELGAS SUPP.LY

VENT ·I>-----f-U"'---'

l ~TARTVAlVEENGINE SIGNAL PRESSURES:

MOUNTED EQUIP-MENT (l) STARTS TO OPEN @ 6 PSI

(2) fUll OPEN @20 PSI

FIGURE 18FUEL GAS

STARTING SYSTEM

Air-Fuel Diagram GTL: Detailed steps for the adjustment ofthe air-fuel system is furnished with new units and conversionkits; the steps should be specifically followed when setting upa new control panel or starting a GTL unit. As indicated by referring to Figure 17, the simplified control system decreasesthe sensitivity to fuel pressure by having the governor onlycontrolling the metering valve or gas manifold pressure as afunction of gas manifold pressure.

Figure 19 depicts a sample 8GTL Air-Fuel Curve. Based ongas composition, gas and air manifold temperature and elevation, each GTL engine must have a specific air-fuel curve. Theoffset pressure indicated is the ratio of the value of air manifold pressure and gas manifold pressure required at 600 rpm.The offset pressure is set by the adjustment of a computingrelay furnished with the control system. After setting the correct ratio it should be maintained for optimum air-fuel mixtureto all cylinders.

49

TURBOCHARGED ENGINES "GTL" - Air Butterfly Linkage

111098} 45&AIR MANIFOLD PRESSURE PSIG

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FIGURE 20AIR BUTTERFLY LINKAGE

5


Air Butterfly Linkage: As an integral part of setting thecontrol system the air butterfly linkage should be adjusted inaccordance with Figure 20. With zero air pressure on the aircylinder, adjust the 1-11/16 inch link so that the air butterfly is 7° open.

rASE -B- I A

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L--J .~.C7..L:>.. I '"y y

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FIGURE 21GAS CONTROL LINKAGENOTE: Governor in "0" Position

INCREFUEL

FIGURE 22GAS METERING VALVE

/1& alA.HOLE

Governor - Gas Metering Valve Adjustment: After settingthe control system and prior to starting the GTL engine thegovernor and gas metering valve linkage should be adjusted.First, disconnect the governor linkage at the governor lever(Figure 21) to ~ake sure there is no binding. Then with thegovernor load indicator set at "zero" and the governor set forapproximately 85% of full travel when the engine is operated atfull load, set the gas metering valve. This is accomplished byadjusting the control shaft between the governor and meteringvalve until the 3/16 diameter hole is exposed as indicated inFigure 22.

Engine operation GTL: The general combustion characteristics, tendency toward detonation if not operated in a slightlean state and exhaust temperature limits, are identical to theGT engine previously discussed. Like the GT air-fuel system,the GTL controls require no further adjustments after they areproperly set. Any changes in engine performance should beinvestigated for their individual causes and not adjusted outby tinkering with the air-fuel control system.

51

TURBOCHARGED ENGINES "GTLA"

Introduction: Historically, engine and compressor manufacturers have concentrated on four basic obj ectives: (1)increased unit horsepower, (2) reduced manufacturing cost, (_,better fuel consumption, and (4) improved reliability. As aresult of these objectives, White Superior developed the turbocharged engine and the ram manifold naturally aspirated linewith Impco carburetion in the 1960·s. Three out of the abovefour objectives were obtained in this development with higherhorsepower ratings, inter changeability of parts, and betterfuel consumption. In the mid-1970's another significant stepwas made toward the fourth objective of improvement in unitreliability with the introduction of the GTL series engines andmodification or updating kits for existing field units.

AIR CLEANER

50 PS

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GOVERNOR

FUELREGULATOR

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JINTERCOOLER

METERI·NG

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CYLINDER HEAD

TURBOCHARGER

INPUT

OUTPUT

AIR/FUELCCMRQ PANEL

EXHAUST~_IF_.O_L_D_--' _

GAS MANIFOLD PRESSURE3-15 PSI

SPEED CONTROL

FIGURE 23AIR FUEL SYSTEM GTLA

5


Today, due to governmental regulations, the manufacturershave added another objective: The reduction of exhaust emissions. Regulatory activity first centered on a definition ofthe emission problem of which both operators and manufacturersco-operated fully by furnishing complete data. The considerations of the trade-offs for cleaner air were evaluated. Fuelconsumption, increased equipment costs, increased maintenancecosts, and reduced performance lost out to lower NOx levelsstipulated by the Clean Air Act of 1977. Since this legislation regulatory activity has increased rapidly, a typical stationary engine emitted 16 grams/BTU-HR of NOx prior to 1977with requirements for this to be reduced to 5 grams/BTU-HR bythe late 1980's. (Reference Figure 25)

Classic methods of reducing NOX emissions include retarding ignition, leaning out the air-fuel mixture, cooling inletair, de-rating horsepower, changing cam timing, exhaust recirculation, converters and water injection. An additional consideration is completely redesigning the combustion chamber butsuch a modification will take considerable research anddevelopment.

The GTLA model engine, commonly referred to as "The CleanBurn", was developed to meet the new emission regulations. Withthe exception to control system problems, the design has beenrelatively trouble free. This has been accomplished by

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53


only making the required external combustion chamber chanathe proven GTL Series. Our discussion, therefore, will bi imited only to variations from the basic concepts reviewed ~revi

ously under Turbocharged GT & GTL Engines. The following summarizes the GTL alterations made to develop the GTLA series.

Air-Fuel Diagram GTLA: The GTLA Air-Fuel Diagram is shownin Figure 23. Variations from the GTL System in Figure 17include:

A. Air-Fuel ControlsB. Dry Type Exhaust ManifoldC. Exhaust Waste GateD. PG GovernorE. PG GovernorF. Pneumatic Ignition Timing ControllerG. Minor Changes to the Start System

Only the variations in the Air-Fuel controls from the GTLdesign will be discussed under this section since each of theother changes or additions will be reviewed in detail followin,this section.

The GTLA control system is sensing input from air manifolcpressure, gas manif9ld pressure, and a 3-15 speed control siqnal. With these inputs an output signal is computed to posithe waste gate so as to maintain a specific air-fuel relat·~n

ship for the specific installation. Figure 24 depicts a s. ~le

8GTLA Air-Fuel Curve. Note that fuel gas specific gravity,heating value, ratio of specific heat (MK M Value), and temperature are an integral part of the curve input data as well asair manifold temperature and elevation. The initial offsetpressure is also indicated, and the GTLA requires a differentair manifold/gas manifold ratio for each speed.

Exhaust Manifold & Waste Gate: The GTLA has a dry typeexhaust manifold and is equipped with an exhaust waste gate asshown in Figure 23. The air-fuel control panel transmits anoutput signal to position the waste gate to control exhaustflow to the turbocharger so as to maintain operating conditions(Figure 24) at the varying loads and speeds. The duel effect isreduction of exhaust back pressure on the cylinder as well asmaintaining exact air-fuel mixture.

Cylinder Head: Instead of being know as the MClean Burn,"the GTLA could just as well be known as the "Lean Burn." Asshown in Figure 25, it is through leaning out the air-fuelmixture beyond the 145% theoretical air point which contributessignificantly to NOX reduction. As the air-fuel mixture isextended past the 160% limit to 185% theoretical air, cylinder

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I TURBOCHARGED ENGINES "GTLA"

65 105% THEORETICAL AIR

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ENGINES

FIGURE 25

ENGINES

combustion becomes unstable. A pre-combustion chamber or torchchamber is incorporated into the cylinder head design to stabilize combustion, through a flame burning ignition process.

As indicated by Figure 26, the air and gas are mixed inthe intake passage conventionally and in addition a secondarygas supply is connected to a pre-combustion chamber. The results are a very rich mixture at the spark plug and, therefore,

55


stable combustion is assured even with a very lean main cpc 21

air-fuel mixture. An example of stabilization effectivene. isthat normal combustion pressure variation is 70-80 psi in astandard engine and 90-100 psi with a lean mixture. The prechamber in a GTLA head stabilizes combustion pressure to 15-20psi.

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FIGURE 26COMBUSTION CHAMBER GTLA

Governor & Ignition: The GTLA engine incorporates a Woodward PG type governor which senses actual speed and positionsthe gas metering valve opening through a linkage (Figure 21)based on an input speed signal of 3 to 15 psig. This same airsignal operates an ignition positioner which controls ignitiontiming. (Figure 23)

Retarding ignition timing as indicated above is a classicmethod of reducing emission. For example, a GIL running atoptimum 145% theoretical air and 35° BTDe ignition timing(instead of 40°) will emit a 15% reduction of NO X ' The penaltyfor such a reduction is a 2% increase in fuel consumption. Whenretarded ignition is combined with a lean air fuel mixture thecombined effect is a 60% reduction of NO x '


Figure 27 is a general view of the GTLA Ignition Timingpositioner and linkage adjustment for the indicated speedsignal. This linkage should be adjusted prior to making themagneto timing changes.

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6007.50900

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FIGURE 27VARIABLE IGNITION TIMING

•The GTLA uses a new metering valve (Reference Figure 28)

which utilizes two o'rings to seal the fuel gas and positiveseat and tapered plug for exact flow/pressure control. Maintenance includes periodic disassembly, cleaning and lubricatingthe o'rings with a light grease .

57


FIGURE 28

GAS METERING VALVE

Starting System: The GTLA also incorporates a Elightvariation of the GTL starting system. The basic system isthe same as that shown in Figure 18 but in addition has arun confirmation switch (Figure 29). This switch is adjustedby lifting the lever arm and checking to make sure the runswitch toggle valve spring projecting lever pops up abruptly.If the projection appears sluggishly adjust the valve springtension.

VALVE SPRINGADJUSTMENT

u

ADJUSTING SCREW

~:=;;~-ARM

TOGGLE VALVE

SPRING SPRING TENSION~==~/ADJUSTMENT

SET RUN CONFIRMTO TRIP AT 450 RPM

SET OVERSPEED TOTRIP AT 990 RPM

FIGURE 29

RUNCONFIRMATION SWITCH


Next, set the adjusting screw so that the run switch valvelever is just switched down when the governor arm is completelydown. Then adjust the governor arm spring tension so that thevalve lever is held firmly down.

Engine Operation GTLA: Operation of the GTLA engine requires additional attention when compared to the GTL. As indicated, the control system is more sophisticated and therefore,dictates more maintenance to operate the unit at designedperformance.

After the engine is running and under load, the exhaustturbine inlet temperature should be checked. The temperaturevaries slightly with the turbocharge type, as indicated below.It is also a good indicator of proper air-fuel ratio and ismonitored with thermocouples and a high temperature shutdowndevice. With loads above 75% the following pre-turbine temperatures should be maintained:

TURBO TYPE PRE TURBINE TEMPERATURES (0 F)

Minimum Maximum Shutdown

FMC 1200 1250 1340

ELLIOTT 1200 1250 13 00

COOPER 1100 1190 1250

e GTLB

After several years of documented operational history onthe first generation clean burn engine (A-version) and withadvancements in new available technology the second generationclean burn engine (B-version) was made available. The sameclean burn principals were applied to the B-version utilizingthe prechamber concept. However a major change was incorporatedinto the concept which was, precision control over the criticalair/fuel ratio mixture. This was accomplished with the installation of a new microprocessor - based air/fuel ratio controller replacing the traditional pneumatic control system.This new controller was designed to operate in conjunction withthe electronic ignition system providing more precise enginecontrol over the various operating speed and load ranges.

This latest electronic system monitors engine speed, alrmanifold pressure, gas manifold pressure, turbine inlet temperature and, air manifold temperature to provide better control ofthe air/fuel ratio throughout the engine's load and speed range.By including the turbine inlet temperature in the monitoring andcontrol scheme the controller can make corrections for variations in the fuel heating values. Improved control over their/fuel ratio and ignition timing accuracy provides a more sta

~le engine operation resulting in reduced maintenance costs.

59

As was stated in the beginning of this section with t' ,passage of the clean air act in 1977 and subsequent amendn. csand revisions through 1990 the emission standards, that areregulated by the state, are based on the best available technology. The Superior clean burn engine meets all of the emission criteria and this includes a new manufactured engine aswell as a converted standard GT or GTL engine. For example, theNOx level for the clean burn engine is 1.5 to 2.0 GRAMS/BPH-HRat 100% design load and speed. This is based on pipeline quality fuel gas, 130 0 F intercooler water and 100 0 F ambient temperature.

AIR CLEANERS

Air cleaners are required to filter out dust particlesfrom intake air to the combustion chambers. There are two basictypes that are common on medium speed engines, wet and dry.Normally, inlet air filters are mounted directly on the enginefor isolated units exposed to the weather, and mounted justoutside the building for units that are enclosed.

Typical design parameters for air filters mounted onengines of the 600 to 2400 BHP range are 2.5" to 3" of waterpressure drop with a 99% efficiency rating, taking out all particles of three microns in size or larger. Typical flow throu r

an air cleaner for a 1000 BHP engine is 6,400 pounds per hour

The wet type air cleaner maintains an oil level in deptl!from 3" to 6" depending on the design. This type of air cleanernormally incorporates a sight level gauge for maintenance ofthe oil level. Air enters through the inlet screens and isdeflected by a rear baffle. At engine idling speed, the baffleautomatically turns (on some models) in such a way that all ofthe air is deflected through the oil, picking up oil dropletsand circulates backup toward the media (or a screen) keepingthe media wet. At increased speeds (increased air flow), thebaffle proportionately opens deflecting a portion of the airthrough the oil with remaining portion going directly acrossthe media.

The filter media should be periodically inspected by pushing inward on the baffle and exposing the media to open view.Media should at all times be well covered with oil. Failure tokeep the media clean will, of course, result in higher airvelocities and, consequently, increased pressure drop with thepossibility of pulling oil into the engine with the air. Withaverage use, the filter should be cleaned a minimum of onceevery three months and more often in areas subjected to dust.At no time should the grit in the sump reach a thickness ofgreater than 1/2". Maintenance is simple and requires only thatthe media be cleaned, oil drained, sump cleaned and media oilreplaced.

6(

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AIR CLEANERS

The dry type inlet air filter may be used in areas thatare not subjected to dust and is probably the most common inletair filter on medium speed engines. Air flow enters through theinlet screen, is directed between media layers and is dispersed through the media to the outlet nozzle. Maintenancerequires inspection of the media and either solvent rinse orair wash cleaning. Under normal use, media should be inspectedon an average of once every three months. Most manufacturersrecommend that the media not be re-used after more than fourtimes of cleaning.

Problems resulting from poor air cleaner maintenance canbe exemplified by visualizing the operation of a turbochargedengine. Since the engine is equipped with a crankcase breathersystem tied upstream of the turbo, oil carryover is a distinctpossibility. Any dust particles which pass the air cleanerswill tend to collect on the impeller as oil film causing anunbalance. The classic example is sand particles which cut thealuminum impeller and enter the combustion chamber resulting inpiston and liner scuffing.

A good indication of an air cleaner requirement on naturalaspirated engines is the amount of pressure drop between theair cleaner inlet and the carburetor inlet. If the vacuum onthe carburetor inlet exceeds 8-inches of water it is an indication the engine is starving for air due to dirty media in theair cleaner.

Dry type air cleaners are recommended for offshore applications because the high humidity results in condensate formingon top of the oil of wet type air cleaners. Dry type air cleaners are also recommended for cold climates because of problemswith high oil viscosity on the wet type. The wet type aircleaner is recommended for all locations susceptible to blowingdirt and dust. All air cleaners should be equipped with a differential pressure device and alarm/shutdown switch.

TURBOCHARGER

Maintenance: As discussed under turbocharged engines, apart of the air supply system is the turbocharger. They aresimply a centrifugal air compressor driven by engine exhaustgases. Maintenance associated with the turbochargers is dependent on the location and air filtration. Initially it is recommended that the turbo inlet be cleaned with a solvent on a 6month basis. In addition. the complete rotor assembly should beremoved and the turbine blades cleaned on an annual basis. Theimpeller side of the turbocharger is not recommended to be

leaned using a wet wash while the engine is running or using2can hulls or walrlut hulls because all of these items end up_In the combustioncharnber resulting in rnilJor filllllre~i. The con

~d]tiorl at the turbo at the time of lnspectlon will dictate tIle

TURBOCHARGER

necessity of changing inspection periods. If it is dirty or outof balance at 6 month intervals, inspections might have to beincreased every 3 months. The main point is to maintain acleaning and balanced rotating assembly at all times.

The turbocharger is a very expensive part of the engineand unlike the engine, operates at very high speeds under fullload conditions. The average operating speed is 16 to 24,000rpm. The turbocharger requires a different maintenance conceptthan the engine because the engine operates a maximum of 900rpm.

It is not recommended to try to extend the life of thebearings, bushings, and seals on turbochargers. These items areautomatically replaced during annual inspection/overhauls. Theexpense of bearings is minimal when compared to the cost ofreplacing a rotor assembly.

Figure 30 may be referred to while reviewing the basiccomponents and operation of the turbocharger .

....

FIGURE 30

TURBOCHARGER

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TURBOCHARGER

Turbine Housing & Nozzle Ring: The exhaust gases from theengine enter the turbine exhaust housing through a speed control device called a nozzle ring. Nozzle rings are sized to agiven engine model for the elevation, based on the required rpmfor the rotor to rotate so as to supply the required air to theintake manifold. The narrow passages between nozzle ring bladesmake it very susceptible to damage from any foreign particlescoming through the engine and into the exhaust manifold. If theitem gets by the nozzle, the turbine will be the next item damaged.

Anytime a nozzle ring ~s replaced, be sure to replace itwith the same part number that is stamped on the face. A nozzlering with a different flow area may be changed by bending thefixed blades but should be done by a service facility withqualified experienced personnel.

Rotor Assemblv: After the exhaust gas passes through thenozzle ring, it is deflected against the turbine blades, causing the rotor assembly to turn. The larger the volume ofexhaust gas the faster the rotor assembly turns. The rotorassembly in turn drives an impeller (or blower), which compresses the inlet air. Whenever damage is detected on a rotorassembly, it is recommended that it be completely rebuilt at aspeciality shop. It depends on the damage, but in most casesrotors with shaft wear and/or bent, broken blades can berebuilt for less than half the original cost. In the rebuildingprocess, the turbine blades should not be repaired by welding.Bad turbine blades should be replaced.

The complete rotor assembly is both statically and dynamically balanced. It has punch marks for locating each part forreassembly. The basic components of the rotor assembly is theturbine wheel (disc), shaft, impeller, nose piece and twoslinger rings.

Intermediate Hous~nQ & Bearings: The rotor assembly issupported by oil lubricated, tri-metal bearings located in theintermediate housing. The lube oil enters the water cooledintermediate housing through a tube which is sealed at bothends. Lubrication is pressure fed to the bearings and thengravity flows to the bottom of the turbo where it is piped backinto the engine crankcase.

Seals around the oil tube prevent the transfer ofoil/water to and from one system to the other. The lube oilpressure to the turbo is normally greater than the water pressure so if a seal leaks around the oil tube, the normal detection would be lube oil in the expansion tank. Every time theturbo is in for a major overhaul, the oil tube seals should bechecked and replaced as required.

63

TURBOCHARGER

Cooling water enters the intermediate housing at the b'tom, cools both the intermediate and exhaust ends, exits at _,Ietop and returns directly to the engine thermostat assembly.

Bolted to both the turbine end and inlet end of the intermediate housing are two labyrinth oil seals. These seals run onthe rotor oil slingers and prevent the passage of oil out ofthe bearings into the exhaust or inlet.

Turbochargers are furnished with a bearing insert toolwhich fits into the I.D. of the bearing and through a stud andnut arrangement actually pulls the bearing into the intermediate housing. The bearings are marked so they can be lined upwith locating pins. Once the bearings are in place, they areheld in the housing by an interference fit of approximately.001. Experience indicates that each time a bearing is pulledinto place, with this particular tool, metal is scraped fromthe O.D. of the bearing; therefore, once it is in place it endsup with an even or loose fit. Once the bearing gets loose, eventhough it is held in place with the small locating pin, thechances are good the rotor assembly will be damaged. Todaysrecommendation is that these bearings be frozen and droppedinto the intermediate housing.

Blower Inlet Casing: The blower inlet housing is designeQso it can be easily removed to inspect and clean the impellerIt is recommended that a flexible connection be installed bltween the air cleaner and turbo to facilitate cleaning and toeliminate the possibility of a distorted blower inlet casing.Any distortion on the blower end of the casing may cause damageto the defuser and/or rotor assembly.

GOVERNORS

Mechanical: The old mechanical governor operates on a flyweight principle and is gear driven off the front of thecamshaft. The faster the drive gear rotates, the further theweights are forced outward. The center part of the fly weightlifts as the rpm increases, and in turn changes the position ofthe lever, which through the linkage and air-fuel system, controls engine speed. To increase engine speed the spring pressure is decreased. This is accomplished by backing off on theadjusting screw. To decrease engine speed tighten down on thespring.

The advantage with this particular type governor isstrictly cost. It is a less expensive design than the moresophisticated hydraulic governors. In addition, it does nothave an adapter drive assembly that is required for the othertype governors.

SPEEDCONTROLSHAFT

------.~_._--_...

GOVERNORS

The disadvantage with the mechanical governor is that itis not as speed sensitive as hydraulic governors. The capablespeed control is no better than ± 10%. But even with the disadvantages, mechanical governors have been used for years andstill remain on many engines. From a normal maintenance standpoint, only the bearings require replacement. If completereconditioning is required, an exchange governor is required todecrease the amount of down time. The design is so simple thatthe mechanical governor does not have to be repaired in a specialty shop.

Hvdraulic: Conversion kits are available to convert frommechanical to hydraulic governors. The standard method of conversion is quite extensive because the camshaft drive hubassembly, the governor drive gear, a governor drive adapterassembly must be added, in addition to the purchase of a hydraulic governor. So the cost of conversion is quite high.Governor adapters are available, however, thereby only requiring the installation of the adapter and new governor.

TOP COVER

FIGURE 31

GOVERNOR

65

GOVERNORS

Most engines today have hydraulic governors manufacture·by Woodward. The two basic types are UG8L and PGA models. Th~

PGA governor has an internal air control feature whereby speedcan be controlled through a remote signal, holding either compressor suction or discharge pressure constant. Figure 31 is aUG8L governor. This is a lever type governor that can be fittedwith a pneumatic actuator so speed can be remotely or automatically controlled with an air signal.

The UG8L governor is simple, as far as operating adjustments and servicing. The lubricating oil is contained withinthe governor. It should be 30 weight and in most cases the sameoil that is used in the engine is used in the governor. In somecases, however, transmission fluid is the oil used in the governor. In comparing the two types of oils the opinions vary.With a good quality lube oil, such as a single grade 30 weight,it provides sufficient lubrication throughout the hydraulicsystem and through all the various wear components internally.The basic problem with straight mineral oil is that varnishbuilds up over a period of time and requires that the governorbe disassembled, cleaned and tested. This is normally done in aspecialty shop. When transmission fluid is used, the varnishingproblem is solved but the lubricity of the oil is not sufficient and a high wear rate on the parts is experienced.

When changing out a governor the following proceduresshould be observed.

1. The drive coupling and drive shaft should be checkedfor wear.

2. The governor should be properly mounted on the engine.Mounting surfaces should be smooth and flat. A papergasket should be installed between the base of the governor and the mounting base and the UG-8 governor bolted down with no side load on the driveshaft.

3. Fill the governor with oil to the proper level as seenin the sight glass. The oil should be clean and free ofair bubbles.

4. The linkage, (fuel or air) should be properly connectedby following the instructions in the Superior partsmanual. The linkage should use approximately 2/3 rds.of the total governor travel or stroke to go from noload to full load. There should be no binding in thelinkage.

5. Make sure that there are no air leaks or blockages inthe air supply line to the pneumatic actuator and thatthe proper air pressure is being supplied.

6. The compensation setting and the needle valve must beadjusted properly for optimum governor response.

GOVERNORS

The governor holds approximately 11/2 quarts of oil. Thegovernor oil is both a hydraulic oil and a lubricating oil andmust be clean. Dirty oil causes 50% of all governor problems.The recommended continuous operating temperature of the oil is140 0 F to 200 0 F. The oil temperature can be measured on theoutside lower part of the case. The actual oil temperatureinternally will be approximately 10 0 F warmer.

Some minor operating adjustments required with the UG8Lare as follows. The first adjustment uses the compensating needle valve and compensating adjustment pointer to eliminate airfrom the governor, which may create a surging or hunting effectcausing an unstable linkage control. With the compensatingadjustment pointer in the minimum position, (open) slowly turnthe compensating needle value in a counter clockwise direction,allow the engine to hunt or surge for about one-halfminute. This procedure runs the governor hydraulic valvesthrough their full cycle and bleeds the trapped air from thesystem. As the compensating needle valve is turned clockwise,the governor will become more stable and stop surging. Checkthe position of the compensating needle valve screw. Next slowly turn the screw until it seats. The screw should then beturned open so as to be approximately within one-quarter turnfrom seating. (From zero to one-quarter turn opening is thenormal position for the compensating needle valve.)

~ If the governor fails to stabilize prior to seating, itwill be necessary to increase or raise the compensating adjustting pointer two divisions toward the maximum position andrepeat the previously outlined steps. This procedure will enable the governor to react faster on installations whereengines driving generators see a sudden load change. Underthese conditions the governor has to grab the load without losing cycles. To hold the load the compensating needle valve mustbe In a minimum position and the governor stable.

On compressor units the normal method of adjusting thegovernor is to move the pointer to maximum, then make the compensating needle valve adjustment to get the air out. It is notnecessary to set the pointer at the minimum position becausecompression units do not normally have sudden load changes. Thegovernor does not have to react fast on this type of application, since the most important thing is stability.

The next setting that must be made is the low speed stopscrew adjustment. When the governor receives a minimum air signal, it is normally desired to maintain a minimum speed on theengine. The low speed stop screw is located at the top of thefront control panel. A lock nut and screw are used in theadjustment to obtain a minimum speed setting. l'he goverrlor

67

GOVERNORS

shaft, when it is decreasing in speed, will turn counter clotwise. The low speed stop lever will also turn counter clockl °euntil it strikes or hits the low stop speed adjusting screw. ASspeed increases, the shaft will rotate clockwise and the highspeed stop lever will strike the high speed stop screw locatedat the center left side of the front panel. The high speed stoplever, also adjustable externally, is on the side of the governor with an adjusting screw and lockout. This adjustment willset the governor so the engine will only come up to a maximumspeed.

The governor is a device with internal valves and mechanisms which are controlled hydraulically, by removing the topcover plate; the shutdown rod is exposed. This shutdown rod canbe lifted by hand to bleed the internal valves and the governorwill go to zero speed. The opposite happens if the rod ispushed down. As a backup to the high speed stop screw, adjustthis rod at maximum speed so it is just starting to bleed offoil; then if the speed increases past the setting, this rodwill unseat the valves and the governor will hydraulicallyreturn to a lower speed setting, for additional maximum speedprotection.

MAINTENANCE

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00

00 °0

The air-fuel system maintenance program should make surethe engine is suppli€d with the design volume of clean air atall times. The fuel supply system should also be clean, dry n.of design heating value. Both the air and fuel must be prop, ymixed and the controls properly set and balanced to distribuLethe load evenly throughout the engine. The governor and linkageportion of the control system should be capable of maintainingthe required air-fuel mixture throughout the operating range ofthe engine. Once the controls are properly set they should beleft alone, with only the necessary adjustments made for unitprotection. One of the biggest sins associated with the operation and maintenance of medium speed engines is tinkering withthe adjustment of balancing valves to compensate for poor performance of a cylinder, and then overloading power cylindersperforming at design horsepower.

FIGURE 32A

BEDPLATE

BEDPLATE ASSEMBLY

GENERAL

Having completed the discussion on systems, an engine willnow be assembled starting with the bedplate (base) assembly.For the purpose of this review, the bedplate assembly will consist of the bedplate, bearings, crankshaft, flywheel andstarter.

BED PLATE

As shown in Figure 32, the bedplate on Superior engines iscast iron and is heavily ribbed to form a rigid structure tosupport the remainder of the engine.

The first machine operation on the bedplate is to mill thebottom or the feet. This machine surface is used as a reference for establishing the centerline of the crankshaft, all theway up and including the top of the cylinder block. This isimportant because this is the same machined surface that isused when it comes to aligning the unit properly. In some ofthe higher speed engines the crankshafts are mounted as anintegral part of the cylinder block. Superior V and Inline 825model engines have bedded crankshafts.

The next machining operation of major importance is lineboring the bedplate and bearing caps for the crankshaft.

r, - , ,~, ~~

.~.

~r--

lEi=- t:;::1

u:== 0 ,b C 0 0 0 0 0 c 0 0 ·~ . ~

a::= ·0 n c on .

ce:==.1

($0 0 0 0

~:D · ~./ '-- I

FIGURE 32B

BEDPLATE

69

BEDPLATE

Machining repairs on bedplates, in the field on the ori~

nal engine, must be done properly. These are transverse mer rswhich are tightly fitted with bearings to support the crankshaft.

On an Inline engine there is always one more main bearingthan the number of power cylinders. On a V 12 engine there areseven main bearing saddles. V 16 engines have nine main bearingsaddles.

The bedplate must be properly installed because with a bedmount crankshaft any distortion, due to torquing of the skid orthe foundation bolts, will be passed directly to the crankshaft. During the torquing process it is important to dialindicate the pull-down at each hold-down bolt. Any pull-downgreater than 3 thousandths requires shimming.

The bedplate is an expensive part of the engine. Bearingfailures can result in the bearing rotating within the saddle.When this happens, heat transfer is experienced to the pointthat the bearing bore becomes distorted. Normally the bearingcap sides will pull in toward the shaft. Repairs of such failures must be done by an experienced machine shop.

The repair processes requires that the outside of the capbe built up to fit the base. The next thing that is requiredto mill off the bottom of the cap at the base side of the p->ing line. This drops the centerline of the cap bore so the mplete assembly can be line bored. If lined bored properly, allsaddles will be in line within .0015.

Anytime the crankshaft is out of the bedplate, the bearingcaps should be reassembled and torqued. The bore of each saddlemust then be "miked" and checked for straightness to be assuredthat there is no distortion. Even when no bearing failure hasbeen experienced, a crankshaft can be damaged or broken at thenext start-up. So every time there is an opportunity, the bedsection should be checked.

It is important to remember that when the bedplate is linebored at the factory, the bearing caps have a rough cut bore.First the caps are machined to fit the bed, then the completebedplate is machined or line bored with the caps in place. Thecaps are numbered at each journal. Anytime a bearing cap isremoved or a bearing change is made, it is important to markand put the cap back in the original position. Normally, thecaps ar~ numbered from 1, consecutively, starting opposite theflywheel end. The cap number is stamped on the port side of thecap and the same number is stamped on the port side of the bedplate. In effect these numbers are match marks. Unfortunately,

BEDPLATE

the bedplate number can only be seen with the cylinder blockoff. The caps must be put back in the same manner as wereremoved, not only in the same place, but in the same position.

The bedplate should also be inspected for cracks betweenstuds or fretting between the caps and the bedplate. Also, dyecheck for cracks or heat checks in the bedplate at the mainbearing saddles and web adjacent to the main bearing bore.Under no condition should parts be reassembled with possibleevidence of distress or distortion.

The bedplate is also machined to accommodate the lube oilmanifold and passages are drilled into each main bearing areafrom the oil header connection. After bedplates have been vatted and steam cleaned, these drilled passages should be blownout with air and checked to make sure there are no obstructions.

BEARINGS

The bearings that are recommended for medium speed enginesare Tri-metal bearings. A Tri-metal bearing is a prefinishedprecision made steel backed component lined with an appropriatebearing material that is capable of withstanding the appliedload and be compatible with the crankshaft. This particulartype of bearing offers the best service to engines operating ina dirty environment commonly associated to an oilfield installation. The Tri-metal bearing will withstand higher levels ofbuilt-in dirt particles, oil borne contaminants, and misalignment than aluminum bearings. The load carrying capability ofTri-metal bearings is a little lower than aluminum, however,its ability to operate in the oil industry environment makesthe Tri-metal bearing the preferred bearing in most applications. The dirt that normally would embed into the overlay of aTri-mental bearing will start wiping an aluminum bearing. Thewiping effect will cause the aluminum bearing to get hot andwill have a tendency to bond to the crankshaft resulting inextensive crankshaft failures.

The various layers of a typical Tri-metal bearing areshown in the following sketch.

FLASHOVERLAYINTERLAYER

LINING

STEEL

71

BEARINGS

STEEL: Bearings are steel backed and the lining is boneto the steel.

LINING: Provides high load carrying capacity and comformability, corrosion resistance and durability at operating temperatures.

INTERLAYER: Generally reduces the wear rate and increasesthe corrosion resistance of the overlay.

OVERLAY: Provides better comformability and embeddabilitycharacteristics and improves the wear rate and bearing life.Crankshaft wear is also reduced.

FLASH: Applied to the bearing bore and back for protectionagainst corrosion prior to the installation of the bearing.

The proper installation of the main bearings and the various items that should be checked during the installation is ofmajor importance. There are two types of main bearing designs.There is a dowel type, which is the standard for the olderSuperior engines, (prior to 1972), and the tang type which arestandard for late model engines. It is important to note thetype of bearing that is installed in each engine. One reasonfor this is when changing bearings in a engine without removalof the crankshaft, a bearing removing tool is used to roll tp~

bearings out of the saddle. If the bearings are of the tangtype the bearing must be rolled out from the opposite tangside.

During the installation of tang bearings, the bearing mustbe properly aligned and located to where the tang is in thecenter of the machined recess portion of the bed.

It is also very important that while the bearings areremoved from the saddle and prior to installation, that theshaft and bearing saddle is free from foreign particles of anytype. Dirt between the bearing and saddle will distort thebearing and decrease the life of the bearing. It could possibly create a major failure shortly after an overhaul. Thecrankshaft and bearings should be cleaned and properly lubricated with lubri-plate or lube oil prior to installation.

On dowel type bearings, the dowel pin is always located inthe main bearing and connecting rod caps. This type bearing,after the lower half is installed (or rolled into position), isaligned with the upper half of the bearing. Since there is nolocating tang, the lower half of the bearing could be rolled inimproperly and could be resting on the fillet of the crankshaft. So prior to torquing, use a screw driver to slide thebearing over to obtain proper alignment with the top half.After installation of the bearings the caps must be properlytorqued by a stagger type torque method.

eI

BEARINGS

The bearing saddle adjacent to the flywheel, will alwayscontain the thrust bearing. On Inline engines the thrust bearing is of a flange design while on the V engine two thrustrings are installed along with a standard main bearing. Afterthe bearings are installed, design crankshaft thrust is normally .005 to .010 inch. The thrust bearing is always in the lowerhalf except on the model G5l0 engines where both halves of thesaddle adjacent to the flywheel are thrust bearings.

All bearing wear is a result of the function of the particular engine, conditions under which it has been operated, andthe lubrication it has received. These are the evaluationswhich the mechanics must be able to make to determine if bearlife is satisfactory.

There are four methods available to the mechanic forchecking and inspecting bearings.

Oilflow: Quite often the engine or compressor will beequipped with a sufficiently sized pre-lube pump to permitinspection of bearing leakage, which is a good means of determining suspected bearing wear or increased clearance.

Bump Check: Another way of checking bearings is the "bump"checking method. This method requires some practice and care,but properly used, it can be a valuable tool. To perform thisoperation, the following items must be kept in mind.

Dial Indicator - __......

to 1fIe••ureClearance

.... inCap

.Jack

Wood Support --!=f----:to distributeload in base

FIGURE 33MAINS RODS

BEARING CLEARANCE73

BEARING

(1) Main Bearing - See Figure 33. First, be assured thatthe shaft on the particular main bearing to be checy~~

is lying in the saddle. This can be done by applyinair to the cylinder with the piston on TDC, on thepower stroke or using a jack or port-a-power insidethe frame to load the shaft.

NOTE: Lock the flywheel to prevent rotation whenperforming this check.

Evidence that the shaft is not bottomed in the saddleis an indication of possible misalignment and requiresfurther investigation. However, near the flywheel endof the engine, the shaft may tend to lift out of thesaddle due to flywheel weight, so this phenomenon isnot always an indication of misalignment.

When applying air or jacking downward and the shaft isout of the saddle, the dial indicator will start toread the movement. After the shaft "bottoms", the dialwill stop; however, continued jacking can cause thedial to again start to move, but at this point theshaft will be deflecting. Stop jacking when the dialindicator stops reading, to prevent damage to parts.If no movement is noted with moderate jacking force or40 psi air pressure (applied in 10 psi steps), then itcan be assumed that the shaft is down in the saddle.Next zero the dial indicator and remove the air pressure on the cylinder.

NOTE: 40 psi is usually adequate for this check, butwhere heavy flywheels are employed or wheresevere misalignment is encountered, it may benecessary to go higher.

When jacking up on the shaft, at some point the dialindicator will stop; further jacking will start theindicator reading again but now the shaft is deflecting. Caution: It is possible to damage parts or puncha hole in the base, so jacking should cease when theindicator stops the first time. The dial indicator atthis point will indicate the total bearing clearancewhich should be .004 to .008 inches.

(2) Rod Bearing - It is easier to check rod bearings ifthey are resting on the upper shell. All that isrequired is to roll the engine until the pistonapproaches TDC on the compression stroke (do not crossTDC or the piston may tend to hang on the rings). Theninstall a jack as shown in Figure 33 and jack the rod

4+.... 1.&3&.&);£

74

-

BEARING

up until the dial indicator stops which is the totalclearance. Design rod bearing clearance is .003 to.007. Stop jacking when the dial indicator stops moving, because further jacking could result in damagedparts or punching a hole in the base.

The procedure outlined above can also be applied toCompressors.

Plastic Gauge: Plastic gauge is sometimes used to checkbearing clearances. It may be used with good results on rodsbut should not be used on main bearings. If it is "humped" outof the saddle, erroneous readings of main bearing clearancescan result, because the plastic gauge will yield before theshaft deflects. Plastic gauge cannot be used to read main bearlng clearance on "underslung" crankshafts.

NOTE: Under no conditions should lead wire ever be usedbecause it damages the bearing surface.

Visual Inspection: The best method of checking bearings isto physically remove and ~isually inspect. First inspect allledges and the bottom of the base (if the oil has been drained)for evidence of metal particles. A magnet can be used to deter~ine if any particles found are babbitt, iron or steel chips.

Care should be exercised in removing the bearings and the.. ~roper tools must be used to avoid damage and "nicking." The~bearing should be inspected for wear or evidence of dirt. In

addition, the bearing should be checked for cracking, flaking,fatigue, corrosion and wiping; any of these items which haveprogressed beyond the earliest stages will require replacement.The babbitt overlay should be at least 60% intact.

Bearing thickness should be checked to be assured they arewithin specification and do not exceed allowable wear limits.In addition, thickness of each new bearing shell should bechecked before installation.

The back and mating edges of the bearing should be inspected for evidence of "working". The backs of the bearing andthe bore which holds it should be inspected for trapped dirt.Metal transfer or high spots must be removed from bearing boresby scraping smooth before installing new bearings to preventearly failure and possible shaft damage.

Whenever possible engine or compressor bearings should be100% inspected. Further, if the unit has suffered a bearingfailure or a complete overhaul is anticipated, the importanceof a complete inspection is evident. A 100% bearing check means

75

BEARINGS

that all rod and main bearings are to be removed and inspecte~

as outlined above.

In fact, all good preventative maintenance programs on aperiodic basis would include a visually inspectiory of the bearing at the flywheel end, one at the center of the 'engine andone at the front end. Bearings should be spot checked on anannual basis. On the next bearing inspection, pull the bearingson the next throws to those previously inspected so eventuallyall bearings are visually inspected.

There is one thing that should always be remembered whenchecking bearings, that is which half is the loaded half. Itwill always be the upper half of the rod bearing and the lowerhalf of the main bearing. Always inspect the loaded half of thebearings.

The procedure used to remove bearings results in a forceapplied to the bearing through the removal tool that may distort the bearing; therefore, the bearing crush may be disrupted. It is not worth the gamble to re-use a bearing, even if itis found to be in good condition.

When checking bearings always record dimensions andobserve condition to provide evidence of alignment, dirt problems, and cap fit. Once a bearing is removed, it is recommendecthat it be replaced. It is also recommended to always replac'both halves because of the crush factor.

Bearing Damage: The causes of bearing failure is oftentimes quite difficult to determine. The bearing design, manufacturing technique, etc. can be at fault but in a very largepercentage of cases the cause lies with an extraneous source.The purposes of our next discussion is to appraise the mechanics and operators of the classic causes of bearing damage orfailures so proper decisions, as to corrective action, can bemade.

Anytime bearing damage or failures are experienced or anytime bearings are removed, it is important to identify and markthe bearings so that at a later date, their condition can bereviewed and compared so cause of failure can be determined.Mark which is lower half, which is upper half, and the saddleor rod number.

The classic causes for bearing damage and eventual failureare as follows:

(1) Dirt Contamination - In excess of 50% of all bearingdamage is directly related to dirt contamination.Dirt is defined as any extraneous material, be it

FIGURE 35

MISALIGNMENT

FIGURE 34

DIRT CONTAMINATION

ferrous or non-ferrous. These contaminates can comefrom the combustion process, be a part of the assembled crankshaft, bearing, engine or compressor, or beentrained in the oil through breathers, strainers, orfilters. The most common result is abrasive scoring asshown in Figure 34. The recommended corrective actionis to flush the lubrication system, change oil, orfilter elements.

(2) Incorrect Assembly - In excess of 25% of all bearingdamage can be attributed to incorrect assembly. Inthe assembly process, it is important to make surethat there is no foreign particles between the bearingand housing, the interference fit is correct, there isno mis-alignment, and the correct bearing half isinstalled. Figure 35 is an example of bearing damagedue to misalignment. Note how the bearings are worntoward one edge.

The next most common assembly error is a particle onthe bearing a.D. distorting the bearing and pushing itinto the shaft; therefore, eliminating clearance,causing a hot spot. The recommended corrective actionis to correct mis-alignment, investigate and correctinterference problems, and make sure housings andbearings are properly cleaned.

77

BEARINGS

FIGURE 36

WIPING

FIGURE 37

CORROSION

(3) Pre-Lubrication - The next major cause of bearingdamage on Superior Engines and Compressors are wipedsurfaces due to inadequate lubrication at start-up.Wiping of a surface is evident when surface rubbing,smearing or melting is evident. This can be causedby inadequate clearance (bent shaft), fast loading,or inadequate or poor lubrication when the engineis first started (as discussed under the LubricationSystem). Figure 36 is an example of wiping of a bearing surface. The recommended corrective action is toadd a pre-lubrication system and to reduce load atstart-up.

(4) Corrosion - corrosion of the lead in copper-leadand lead-bronze alloys is caused by acidic oiloxidation products formed in service. Examplesinclude contamination of the lube oil with watercoolant or the decomposition of oil additives. Figure37 is an example of corrosion damage due to ethyleneglycol attack. The recommended corrections are torun an oil analysis, stop water leaks, and flush,as discussed under Coolant System.

7

BEARINGS

FIGURE 39

FATIGUE

FIGURE 38

CAVITATION

(5) Cavitation - Cavitation 1S an impact fatigue attackcaused by the formation and collapse of vapor bubblesin the oil film. Normally, the harder the bearingsurface the greater its resistance to cavitation.Discharge cavitation is exemplified in Figure 38caused by a rapid collapse of vapor bubbles in theclearance of an unloaded bearing half. Correctiveaction includes increasing oil pressure, reducingclearance or changing to a harder bearing material.

(6) Fatigue Cracking - This is caused by dynamic loads 1nexcess of the fatigue strength of the bearing material. The fatigue strength of lead-based overlays aregreatly reduced when bearings are subjected to hightemperatures. Engine overloading, compressor unbalance or un-cylindrical shafts are classic exampleswhich result in damage due to fatigue cracking, asshown in Figure 39. Recommended action include correcting balance (which is discussed under compressors), mis-alignment and causes resulting ln an overload condition.

79

CRANKSHAFT

Medium speed engine and compressor crankshafts are dieforged from a solid billet of high quality steel and accurat Jmachined. As discussed under the lubrication system, oil passages are drilled from the center main bearing journals to thecenter of crankpins to lubricate rod bearings and to carry oilup through the rod to the piston pins and pistons. As indicatedin Figure 40, the forward end of the crankshaft is extended forauxiliary and camshaft drives. The rear end of the crankshafthas an integrally forged flange for the flywheel and powertake-off. Oil throw rings are machined on the shaft in-betweenthe thrust bearing flange and power take-off flange to preventoil from escaping around the shaft and rear end cover.

probably the most important thing to remember is that anytime a bearing is pulled because of a failure, a completecrankshaft inspection must be performed. This includes the following:

(1) Inspect the crankshaft for evidence of dirt scratching. Indications of this sort requires an investigation of the filtering system.

FIGURE 40

CRANKSHAFT

(2) The journal should be dye checked. Particular attention must be given to the fillets and the oil holesbut the complete journal should be dye checked. Theare three basic reasons for this.

CRANKSHAFT

(a) Small defects can be detected and "dimpled" outin many cases to renew the integrity of theshaft. The stoning of "high spots" is not goodenough.

(b) When unrepairable cracks are found, the shaftmust be replaced. This will avert a completefailure which could result in serious tear-upand damage to other parts.

(c) If nothing is found, the shaft integrity of thatparticular journal is assured based on theinspection. The above recommendations are merelygood maintenance practice. All medium speedengines are subject to shaft failure, and anything that can be done to insure shaft qualityshould be adopted as standard. Dye check is soeasy to use. There is no excuse for not takingthis precaution; after dye checking, all evidenceof the dye check should be removed with suitablesolvents.

(3) It is sometimes necessary to determine whether or notthe crankshaft is bent. Serious wrecks, hydrauliclock-ups, or completely ·wiped" bearings are typicalfailures which could either lead to a bent shaft orbe caused by a bent shaft. Main journals may bechecked by dial indicator but the following should bekept in mind:

(a) When rolled, the crankshaft will tend to crawlup and slide down in the mains. Use a greasepencil to mark the starting point on each journal and zero the indicator at the start. Be surethe spark plugs are removed or the compressorvalves removed on the compressor.

Roll the shaft through three complete revolutions and record the readings each 90°. Somevariation will be noted due to the "crawl"effect described above, but in general, thereadings for each of the three runs should beconsistent, regardless of the results. Remember,the shaft is flexible and it is not being turnedbetween centers, or in V blocks,so some variation is to be expected.

•(b) At the flywheel end, the shaft may tend to lift

out of the saddles; therefore, readings in thisarea are in general more erratic. It is goodpractice to loosen all chains and belts. Thisis especially true when they are adjacent to the

81

CRANKSHAFT

journal being checked.

(c) This discussion should indicate that while itmay be quite easy to detect a badly bent shaft,it is sometimes very difficult to detect slightbends. Shafts which continually "wipe" bearingscertainly make a bent shaft suspect, and a thorough inspection of the whole assembly would bein order.

Bent crankshafts can be repaired by removing the shaft andpenning or preferably by placing the complete crank in a vat,heating it, and applying force to straighten.

Most major problems with crankshafts are caused by eitherbearing failures or by mis-alignment (which also contributes tobearing failures). Based on experience of inspecting many broken crankshafts over several years, Superior shafts tend tofail in bending not in torsion. Mis-alignment is the main causein excess of 90% of the failures. The integrity of the crankshaft forging is not normally the cause of failures.

Properly reconditioned crankshafts, chromed mains and rodsback to standard, are as good or better than new shafts. Thefirst thing that must be done is to assure that the core isgood. This is done by a 100% magnaflux inspection. Cores withsmall cracks and heat checks can be repaired by welding by reputable firms with experience in the correct procedure. Weldcrankshafts, however, are not recommended for installation iI,Superior Turbocharged Engines. The optimum amount of chromebuild-up on mains and journals is .020 inch.

TORSIONAL VIBRATION PAMPNERS

Vibration dampners are installed on the front end of thecrankshaft behind the front end cover on (6) cylinder inlineengines and (12) (16) cylinder vee engines. The purpose ofvibration dampners is to dampen the critical crankshaft torsionals and to control the flexing of crankshaft vibrations.They also extend the life of auxiliary drive systems includinggears, chains, and chain drives for camshafts, water pumps,lube oil pumps etc. The dampner case contains free floatingparts with very close tolerances and a viscous silicone fluidproviding the dampening effect.

The life of the dampener is dependent on the various operating conditions and unit application. Some of the problemsexperienced in the past are:

1. Outer case damage resulting from rough handling duringshipment or installation.

TORSIONAL VIBRATION DAMPNERS

2. Bearing wear which will contribute to wear in otherparts due to an increase in clearances.

3. The loss of the viscous silicone fluid caused by breaking the seal.

4. Due to time and temperature the viscous silicone fluidwill break down and turn to a granular powder.

Because of the above mentioned problems it is recommendedthat vibration dampners be replaced after 35,000 operatinghours. The front end cover must be removed to gain access tothe dampner.

Test equipment to test vibration dampner ln the field isnot available.

FLYWHEEL

The offset of the forces of reciprocating components andevents of combustion are counteracted by use of flywheels. Theflywheel inertia effect assists in uniform speed, acceleration,or deaccelleration of the engine. When attaching flywheels tocrankshafts inspect the holes in the flywheel and shaft for"fretting" or elongation; inspect the fitted bolts; installwith match marks together so that the timing marks will be correct, and torque the bolts.

An item that has created some problems in the past is theflywheel ring gears. Superior ring gears have an interferencefit with the flywheel of approximately .040. For proper engagement of the external starter bendix, the tapered gear sideof the ring must be installed toward the cranking motor. Excessive number of start-ups and/or start-ups during cold weather result in most ring gear damage. Old style flywheels can bemachined to accept ring gears when converting from internal toexternal air starting.

STARTERS

The most common starting system on medium speed engines isthe external air or gas pneumatic cranking motors. The starteris driven by forcing air or gas through a vaned rotor. Speedreduction gears drive a bendix mounted on the rear of the motorthat engages into the flywheel ring gear. When the crankingmotor reaches a fixed rotating speed, the bendix disengages.One of the most important items is to make sure the starter isproperly aligned and properly mounted. After alignment ischecked the bracket must be dowelled to the bedplate or bracket.

There are two basicengines. The old system,

types of starter systems on Superioror the original system, was internal

83

\

STARTERS

FIGURE 41

STARTER

air start. The start valve for this type of system is locate~

on the front of the engine near the governor. By pulling alever, air is admitted to each power cylinder in a normal firing sequence and rotation of the engine is achieved. The disadvantage with the internal air starting system is the requiredmaintenance of components, equipment that is required, such asair compressor, air starter tanks, etc. The other disadvantagewith the internal air starting systems is the air admitted toeach cylinder must be dry because wet or moist air entering thepower cylinder will result in fouled sparkplugs.

The external air starting system offers several advantages. One, wet air is not admitted into the power cylinder.Secondly, the engine may be started with only 150 psi of airpressure and if air is not available, fuel gas may be used.This system also simplifies repair of heads, camshafts, andreduces maintenance costs. Kits are available for the conversion of all older units to external air starting.

Figure 41 is a cut-away of a typical cranking motor. Oneof the major repair items is the vanes, part of the rotorassembly. Damage to the vanes is normally caused by improper

8

STARTERS

lubrication and foreign particles getting into the system, suchas rust flakes or sand during start-up. It is important to filter the air or gas that is coming into the starter. A lubricator in the inlet line provides lubrication to the vaneswhich reduces wear, but over a period of time the vanes willhave to be replaced.

At the end of the starter bendix shaft, there is either abronze bushing or a roller bearing. It is important that thisbearing surface be lubricated on a periodic basis. During longperiods of cranking or repetitive cranking, the end of thestarter will get very hot. It is therefore necessary to let themotor cool down and then make sure the bushing is properlylubricated.

In some cases starters are shipped with new engines thatwere not lubricated with grease in the bearing area. It isimportant that the front and rear motor housing have ventedtype grease inserts so they can be manually lubricated on aperiodic basis and prior to every start-up.

85

CYLINDER BLOCK ASSEMBLY

For the purpose of this discussion the Cylinder BlockAssembly will consist on all the remaining items of the e~ neexclusive of the Systems and Bedplate Assembly previouslyreviewed. Specifically, this assembly will include the block,covers, liners, connecting rod, piston assembly, heads, valvetrain, ignition system, and exhaust manifold.

GENERAL

The cylinder block as shown in Figure 42 is cast of highalloy cast iron and is designed for rigid support of the cylinder liners, heads and camshaft. The camshaft bearing supports are integrally cast into the block and line-bored in thesame manner as the bedplate. Removable covers offer access tothe camshaft valve train, main bearings and connecting rods.

Two problems have been experienced with cylinder blocks.The cavitation problem and recommended corrections was discussed under coolant system. Failure due to the block crackingin the cam bore area is prevalent on all Inline engines builtprior to around 1975. The crack begins in the cam bore area andprogresses into the web. Old block cam bore areas were designedfor a 2-inch diameter camshaft and had an integral oil passagewith little or no radius drilled into the bushing areas. Thisproblem is more prevalent on turbocharged than naturally aspirated engines. It is recommended, when the side covers areremoved, that each cam bore area be inspected for cracks.found early the cylinder block can be repaired by a provencasting repair technique.

The new designed cylinder block has a 2-1/4 inch camshaftand is "beefed-up" in the camshaft bearing area as well ascylinder liner area.

INSTALLATION OF BLOCK TO BED

The cylinder block is attached to the bedplate with studsand nuts. Paper thin gaskets on each side of the bearing capsand along the outside edges are used to make an oil tight seal.Prior to installing the block, make sure that both the blockand bed machined surfaces are clean. Apply a light coat of linseed oil to both sides of the gaskets for additional sealant,and torque the cylinder block to the bedplate in accordancewith the sequence shown in Figure 43. After being torqued theblock is then dowelled.

I CYLINDER BLOCK ASSEMBLY

r

",Io'-'o'-------'o'-------'o'-'HL..----''----'o''---''o_-''o-----'tt'''o'------'o'--_O~OI

Line!" ·OD·i-. .. ... '-,

] [ r

~ ~ r.............,.,--../ '.-........,..---:.

...,'"

"' ...............,.... '" ....NN

...,N

FIGURE 42

CYLINDER BLOCK

....'"..., ...,

00 0 00 0 00 0 00 0 00 0 00 0 00

NOO - N~ - NOO~ ...,~ - 00 N -

1

00 N -~ N"'I-- '" .... .... Nf- .... -t- ..., ..., ..,

- - - - t-

o '00 0"- '00 0"- ~~f---- ~ '00 0"-

r--00 0 00 0 0"- 0 00

'" .... .... ,.., N - N 0"- N ,..,'"

..,

00 0 00 0 00 0 00 0 00 0 00 0 00

"" ...'" '"

"" ........... "" ...NN ... "" ... ""..., M

•FIGURE 43

CYLINDER BLOCK TORQUING

87

INSTALLATION OF BLOCK TO BED

If there is the occasion to have to split a recently reconditioned V or Inline engine to remove the shaft, it migt jeof help to mention a suggested procedure. Superior engines ctredesigned so that the cylinder block, connecting rod and piston,heads, exhaust manifold, etc. may be removed as a completeassembly. By taking the flywheel off, plus coupling and auxiliary drives, the connecting rod caps can be removed. By mounting brackets on the block, the rods and pistons can be held attop dead center. Then the entire top section of the engine canbe removed intact.

CYLINDER HEAD STUDS

Old style cylinder blocks were assembled with interferencefit cylinder head studs. During the installation of this typeof stud, it is possible to drive the stud into the cylinderblock and either crack the block and/or the stud. When practical it is recommended that these old style studs be replacedwith the new design studs which have rolled threads, are neckeddown to hold the torque value, and no longer have an interference fit. After making sure the cylinder block threads areproperly cleaned, the new studs should be installed and thentorqued to the recommended value.

MACHINING LINER FIT

The procedure for machining the cylinder block castine _5

to first machine all four sides, then machine internally fliners, etc. It is important to note that when the upper andlower liner seal areas are originally machined it is possiblefor these areas not to be exactly perpendicular to the top ofthe block and not affect the engine operation, because of thedesigned head to block clearance. This item is being pointedout because a lot of shops try to re-work the upper liner seatso that it is exactly parallel to the top of the block and notworry about the o'ring area. Others put in upper and lowerinserts without making sure the upper seat is perpendicular tothe o'ring area. These procedures will result in a "cocked"liner which will not seal coolant water.

CYLINDER LINER

General: The cylinder liner is of a wet type, of specialhigh alloy cast iron construction with a hardness of 210 BNHminimum and has a cross-hatch design in the bore of 25 to 45RMS at 45°. The liner is sealed at the flange with a gasket atthe bottom with o'rings.

CYLINDER LINER

Anytime a piston is removed the liner should be measuredand if found to be within tolerance, honed back to 25 to 45 RMSat 45°. The purpose of the cross-hatching is to help the powerrings "seat-in" at start-up.

Some cylinder liners are honed in place, and when thisprocedure is used the mechanic must make sure that no cast irondust, honing solvent, or washing liquid gets down into thebearings or bedplate. This can be accomplished with a tube andfunnel seal to the bottom of the liner and piped outside thebed. After honing the liner cross-hatch grooves must be thoroughly washed out with soap and water.

Please refer to Coolant System - General for the discussion of scale build-up on liners and Coolant System Cavitation for the discussion of reconditioning cylinder blockswith inserts in the upper and lower liner area.

UDDer Gasket & O'Rings: Originally the liner flange gasketwas made of copper and was .062 inch thick. With the cylinderhead torqued to 450 foot-pounds and an engine that operatedcontinuously, the gasket did a good job of sealing the coolant.This gasket is still available for those customers whom preferthis gasket arrangement. But due to expansion rates of copperand cast iron, the gasket will not seal properly for engineswhich are often stopped and re-started.

The next gasket design was .013 thick and was made ofstainless steel. With this gasket essentially no crush could beobtained. Cleaning the cylinder block seating area became morecritical, and either RTV or a teflon compound had to be used toprevent leaks. In addition, once the liner was in place, it hadto be held down with a tool until the compound dried.

The latest design is a .062 inch thick metal-backed elastomer gasket shown in Figure 44. The metal used is mild steelso the expansion problems are reduced. In addition, a 3/32 inchthick rubber material, which is compatible with ethylene glycol, is molded to the 1.0. of the steel. This gasket increasesthe distance between the bottom of the cylinder head and theblock, so a new thick sponge rubber head to block gasket mustbe used along with the metal-backed elastomer gasket.

Before installing the liner another item should bechecked. Measure the 0.0. of the liner just below the flangeand the 1.0. of the block at the seat area. Improperly designedliners have this clearance at a maximum which increases thechances of water leaks. An additional suggested item to checkis the block seat area for cracks. This should be done by 100%dye check.

89

CYLINDER LINER

FIGURE 44

LINER GASKET

As shown in Figure 44, an option that is available is aliner with an o'ring on the flange 0.0. The o'ring is 1/8-inchdiameter and offers an additional back-up seal to the metalbacked elastomer gasket.

Improperly designed liners also have o'ring grooves whiare not cut to proper depths. It is important to note that ,eblock is machined straight while the depth of the o'rings vdrybased on reduced exposed pressure from top to bottom. Allo'ring groove depths should be measured. Improperly designedliners also have o'ring grooves which are not cut to properdepths. It is important to note that the upper most o'ring actually seals in the "entering chamfer" area of the block.Therefore, the upper most o'ring grooves's bottom diameter iscut larger to insure proper o'ring crush and sealing tension.

Installation: Before installing a liner, the upper linerseat and lower liner seal areas should be cleaned and checkedto make sure they are perpendicular to each other. If found tobe okay, two-thirds of an old liner, turned upside down, with ahandle attached can be used as a lapping tool. The upper linerseat area must be perfectly smooth in order to properly sealthe coolant.

Prior to installation, lubricate the o'rings with STP orlubriplate. As the liner is lowered into the block, care shouldbe exercised not to cut or roll any of the o'rings as they passthe upper liner seat! It is also important to protect the upperliner to cylinder block gasket. Grease may be used to attachthe gasket to the liner.

CYLINDER LINER

The liner should be lowered slowly into place until themachined 0.0. (directly below the flange) is down in the 1.0.of the block. At this point the metal-backed elastomer gasketwill still be visible. With a sharp object lower the gasketdown against the block seating surface. Then the liner can bepressed into place.

Once the liner is in place, the inside diameter must bemeasured to make certain the bore is not distorted. A "cocked"o'ring will distort the bore and cause piston scuffing and/orcontamination of oil with coolant. Even though the liner 1.0.may measure correctly, it is recommended that the lower linerarea be honed (with a stiff hone) to remove any high spotswhich may exist. This measure will reduce the possibilities ofpiston scuffing at start-up.

COVERS - SIDE AND END

The cylinder block has side door covers on both sides andat the center so the connecting rods may be completely exposed,and it also has upper side door covers around the push rod andcam follower areas. All of these doors have gaskets. In addition, the cam bearing caps are machined and have rubber grommetstrips that are installed prior to assembly of the covers andgaskets. After installing the rubber strips, RTV may be applied

~to both the cylinder block and the side cover. This acts as an"'extra sealant. Some customers use Permetex (or some other per

manent type gasket compound) and permanently seal the gasket tothe side cover; then, on the block side of the gasket theyapply lead or some other type of soft type gasket material.This procedure has been successful in reducing oil leaks in thecover area.

The upper side cover plates are of the same type of designbut there is one unique feature about the ones on the cam sideof the block. From the center point of these side covers, downand around the bottom, there are threaded capscrew holes thatare drilled all the way into the inside of the block area. Thefront end cover also has threaded holes which are drilled allthe way into the cylinder block. Anytime a threaded hole isexposed to the internal parts of the engine they are alwayscontributors to oil leaks, if not properly sealed. The methodof sealing these areas, is a special washer that is recessedfor a rubber grommet insert, that will give a positive sealwhen torqued. It is important that these grommets be replacedon a periodic basis so oil leaks can be kept to a minimum.

It is recommended that all cylinder block cover capscrewsbe torqued by starting at the center of the cover and workingyour way out to both ends. The torque valve is approximately 50

_foot-pounds.

91

CONNECTING ROD

General: The connecting rod is shown in Figure 5 as a partthe piston and piston pin assembly. The rod bearing is ofsame basic design as the main bearing and the same prevel .emaintenance principles and inspections apply. Rod bearings ca~

also be dowelled or tanged as discussed under Main Bearings.

Some of the connecting rods that were installed in theolder engines are considered "light rods." The cross-sectiona~

area in the rod throat was marginal and with the rifle drillecoil passage the stress level was high. The light rods have aone piece heavy bronze bushing in the piston pin bore. When t~

turbocharged engine was upgraded from 1,000 horsepower to l,lehorsepower, the light rods started breaking and inspection ofthe piston pin bronze bushing revealed fatigue cracking due tcoverload or detonation. The problems resulted in the design 0:the "heavy rod."

The new design connecting rods are of a much heavier construction. The piston pin bushing is of a two piece design.After new bushings are installed in the rod, they are reamed :a specified size to fit the piston pin. It is recommended the'all turbocharged engines have the heavy connecting rod. It isalso not permissible to intermix light and heavy rods becauseof balance.

Inspection: After the connecting rod bearings are remc·the cap should be re-installed, torqued and the complete rinspected. Special attention should be paid to the big b ~,

make sure it is not "egg" shaped. the connecting rod sho.. dalso be checked for straightness. The piston pin bore thrustsides should be parallel with the rod bearing bore thrustsides. If a rod has thrust sides that are not parallel, itindicates that the rod is bent and the rod must be replaced.The connecting rod cap is match marked to the connecting rod;the same as main bearing caps. The reason for the markings isthe rod and cap inside diameters are line bored with the capplace. Normally the match marks are installed so they face t~

intake side of the engine.

Reconditioning: A rod bearing failure can create heatwhich in turn may cause distortion. Rods which have beenexposed to excessive heat must be replaced. If there is noevidence of heat, the rod can be reconditioned. The firstreconditioning step is to machine the parting edge of the CG~

necting rod cap, which offsets the center of the bore. The ccnecting rod can then be re-bored to the original tolerances.addition, the piston pin bore on occasion is not parallel wi:the large bore and corrections have to be made to assure the:they are properly aligned and perpendicular to the thrustfaces.

W P.

PISTON PIN

The piston pin lS also shown In Figure 5. It is a hollowtype design. The pin has cupped freeze plugs in each end toretain the lube oil and is designed to transmit the maximumhorsepower from the power piston to the connecting rod. The pinshould be inspected for scratches, dye checked for cracks andmeasured for wear after disassembly.

The pln has several holes drilled into the center portionof the pin for the distribution of oil to the bushing and alsoout to the edge of the pin for oil flow up into the top of thepiston.

PISTON

General: As shown in Figure 5 and in the cut-away, thepiston receives an oil supply from the pin and flows throughthe top of the piston. The oil flows through the "cocktailshaker" and gravity flows out of the piston below the pin area.The oil being drained from the piston creates "splash" lubricant for the piston and the cylinder liner.

A plug is located in the top of the piston. The plugserves three purposes: it is used as a rough casting corecleanout; it seals the upper oil cooling area; and, it servesas a means of balancing the piston. The plugs are manufacturedout of different materials and have three different weights. Ifthese plugs are removed it is important they be installed withthe same piston. Piston weights are also maintained by machining the inside diameter of the skirt area. The original plugdesign had an interference fit, and the new design pistons havea flange. Locktite should be applied to the threads of bothdesigns and torqued. If the plugs are not installed properlythey can back out during operation and strike the connectingrod and break off the top half of the piston or the plug itselfwill break and fall down into the crankcase. In either case thenext event is a major failure.

Superior pistons are of a tapered design and it is lmportant to maintain the proper clearance between the piston andliner at all times. The two most common pistons for the 825series are the 10:1 and the 8-3/4:1 compression ratio. The 83/4:1 ratio piston was designed for the low compression engines(GTL), but also can be used for high BTU fuels. There are also8-1/4:1 and 7:1 low compression pistons for the 510 series, aswell as, '7:1 pistons for the 825. The 10:1 ratio pistons havebeen manufactured in a four ring design as well as a six ringdesign. The four ring design was introduced with the SGT seriesengines with the intent of reducing manufacturing cost and oilconsumption. These pistons are totally interchangeable and can

93

PISTON

be intermixed within an engine with no problems. All new pitons today are of the six ring type and have proven to be tbest design.

Another basic change that has been made during the pastfew years is the method in which the piston pin is retainedwithin the piston. The original designed retainer was a castiron cap and the new design pistons use snap rings.

New pistons look black in color because of the ParkerLubriting or phosphate coating process. This coating is a basicpart of the piston design and is functional during the break-ir:period. It actually acts as a lubricant for the piston duringthe normal thrust loading and assists in the piston to linerseating process. There are special tools that are required tolift the piston from the engine, and after removal a completeinspection of rings, the piston and the ring groove dimensionsis required. Carbon build-up within the ring groove is normal.Some other normal conditions that are experienced is scratchln~

in the thrust area. Excessive scratches would be the result ofoverloading or due to an unbalance of an individual cylinder.Another major problem would be detonation. If a removed topcompression ring is broken into a large number of small pieces.it is a good indication that the failure was caused by detonation. It should be noted that the top compression ring isavailable with a chromed outside edge or a moly-insert edgeBoth types are acceptable and equal in performance and li"addition to ring breakage, detonation will cause a comple~.

piston failure (cracked top) and/or cracked cylinder head.

Detonation is auto-ignition of the unburned mixture afre~

the timed spark and is the greatest single factor involvingpiston damage. Detonation is caused by several factors inclJding advanced timing, overloading, excessive oil or otherdeposits in the combustion chamber and high cylinder temperatures. Hot spots on the piston crown or cylinder liner ordeposits can lead to detonation due to the increase in cylinccpressures. Proper piston temperature is regulated by a propercooling system and cooling system maintenance. Cooling systercdeposits such as oxide deposits anywhere on the 0.0. of thecylinder liner will inhibit heat transfer even though the jac}et water temperature is normal. Deposits are formed by imp~o~

erly treated jacket water which allows a corrosive layer tobuild up.

Piston problems can also result from carbon type deposi~

from the fuel gas or lube oil on the cylinder liner or pis~o~

These deposits can lead to detonation and inhibit normal hec~

dissipation. Oil oxidation and nitration can cause a thick isquered deposit to develop in the piston crown and ring areawhich will inhibit heat dissipation.

4

1e

PISTON

Another problem is carbon raking. Carbon type deposits canform on the ring grooves and on the liner above the ring turnaround area. These deposits inhibit heat transfer from the piston and rub against the liner wall scratching or burnishing itsinner surface.

The solution to these types of problems is to properlymaintain the lube oil system and jacket water system. It isrecommended that the oil and coolant be analyzed and the oilchanged on a regular basis. A good quality water and a propercoolant additive package should be used.

The thrust area of a piston is normally between the thirdcompression ring to one inch below the upper oil ring. Whenload is applied to the piston, it thrusts and makes contactwith the liner in the direction perpendicular to the pin. Excessive clearance between the piston and liner causes this normal thrust to become piston "slap". Therefore, the piston mustbe carefully measured in this area during the inspectionprocess.

Reconditioning: If the scuffing progresses below the topoil ring and discoloration is found, it is recommended that thepiston be replaced or tinnized by metal spraying to build itback up to standard.

Starting at the third compression ring to one-inch belowthe upper oil control ring, .003 to .005 can be removed toclean up scratches and the piston can be re-Iubrited and used.Scratches in excess of .005 require metal spraying back tostandard or replacing with new pistons.

Rinas: The recommended piston ring design for the 825series is the six ring set-up. The top four rings are compression rings, the fifth ring is an oil control ring, and the bottom ring is an oil scraper. Inspection should note specificpatterns of twisting or bending of the rings. Prior to installation of new rings, it is recommended that the new rings beinstalled in a new liner and end gap checked. It is also important that the rings be properly installed because they aredesigned with a tapered edge. The purpose of the taper is topush oil toward the top of the piston on the upstroke and during the downstroke to scrape the oil from the cylinder wall.The old oil is actually moved back to the crankcase andreplaced with new oil.

INSTALLATION OF ROD & PISTON

General: Extreme care must be exercised ~n the installation of the piston-rod assembly. The piston and ring should becoated with lube oil for break-in. It is also important to

95


stagger the rings so the end-gap is a different positions oneach and every ring. A 90° staggering method is recommended.This will help to maintain compression and will eliminate excessive blow-by.

In lowering the piston into the cylinder, a properly designed tapered entering sleeve should be used. The originaldesigned sleeve furnished with the engine is not correct. It isrecommended that a sleeve with a longer taper and slot port beused; the ring can be checked to make sure it is properlyembedded in the groove prior to the piston entering the liner.If the ring is improperly installed a ring can be broken without notice during the installation process. It is importantthat the piston be lowered in the cylinder liner very slowlyand that the piston rings are not in a bind in any way. Ringsare very susceptible to breakage. If springs are located behindthe oil control rings, make sure that the combination springand ring can be completely collapsed within the groove.

It is also important to make sure that during the installation process that the piston is properly positioned withregard to power valve cutouts. The largest cutout is for theintake valve and the smaller cutout is for the exhaust valve.These cutouts are for the 10:1 compression ratio piston. Thehillside of the piston should be positioned toward the intakeside of the engine. In the lowering process care must also betaken to make sure the rod is properly guided into position iorder to protect the connecting rod bearing and crankshaft. o.V engines it is necessary to make sure that the rod doesn'tscratch the liner. The use of a piece of felt or leather willhelp hold the rod off the liner wall during the installationprocess. The rod bearing must be well lubricated prior toinstallation and extreme care must be exercised to be assuredthat there are no foreign particles between the bearing 0.0.and rod or the bearing 1.0. Lube oil, STP, or lubriplate areall good installation lubricants.

After the connecting rod is installed in its proper position, the rod bearing clearance should be checked even with newbearings. Since it's impossible to use a feeler gauge, the mostcommon method is the use of plastic gauges. After torquing therod cap the plastic gauge thickness is measured to verify aclearance of .003 to .007. It is also important to note that inthe installation of tang type bearings that the tang has beenproperly located.

Rod Cap Torquing: The connecting rod has four fasteningbolts. Some of the older engines use cotter key type bolts. Analternating torquing sequence stepped in specific increments isrecommended. One problem with the cotter key type bolts is thatafter the connecting rod is properly torqued, it is sometimes


~eqUired to either increase or decrease the torque to obtainproper alignment of the cotter pin hole. This torque variance,in some cases, cause mechanics not to pay close enough attention to the required torque valve and the bearings can becomeloose in the bore. Under these conditions the bolts can comeloose in operation, the rod and cap separate, damage the crankand/or cylinder block.

The new design rod bolts have elastic stop nuts torqued to350 foot-pounds. One question that always comes up is how maytimes can the elastic stop nuts be used. Some customers go tothe extreme of replacing them every time they remove the nut. Ageneral rule of thumb is that if it takes less than 30 footpounds of torque to run the nut down on the bolt, then itshould be replaced. It should also be pointed out that any timea Superior torque value is given, the torque value is based onclean threads on both the bolt and the nut, and the threadslightly lubricated.

CAMSHAFT ASSEMBLY

General: The camshaft on inline engines (as shown inFigure 33) is located in the center of the cylinder block onthe intake side. The V engine has two camshafts, one on eachside. New and reconditioned cam shafts are fitted with solid

~ushings. Split bushings are available for field repairs.~ushings are located on each side of each power cylinder and

there are the same number of bushings as there are main bearings.

The camshaft is driven from the crankshaft at the flywheelend by a roller chain on V engines and at the front end on Inline engines. The camshaft rotates one revolution with two revolutions of the crankshaft. The camshaft sprockets are doublekeyed to the shaft and clamped to the hub by a ring and capscrews which allows rotation of the shaft for timing. A gearoff the end of the shaft drives the governor, overspeed shutdown, magneto, and tachometer.

The camshaft is made of steel and is ground to assurestraightness. The cam lobes are attached to the shaft by aninterference fit and keys. Each power cylinder has an inletcam, exhaust cam and gas cam installed on turbocharged units.In addition, an air starting cam is added for internal startengines. The lobes are made of a high alloy steel, heat treatedand ground.

There has been only one major design change in the camshaft since the advent of the 825 engine. This was the changerequired for the GTL Model and new cylinder block. As mentioned

~he shaft diameter was increased to 2-1/4 inches and the inlet

97

CAMSHAFT ASSEMBLY

and exhaust lobe contour was changed. The only other change,which was made many years ago, was that the lobe track waswidened.

fLEXIBLE ORRIGID DRIVE

FIGURE 45

CAMSHAFT

AIR START 'NC.CAM

rLYW><ELEND IlUSH'NG

Inspection: Part of an inspection program should be aperiodic check for excessive wear on the cam lobes. When wearis found the first suspicion is that the cam lobes are toosoft. In most cases, the wear will continue until the shaft isre-conditioned with properly hardened lobes. Other maintenanceitems which require inspection are the drive gears, chain,sprocket, and fixed and adjustable idlers. These items may beinspected through a rounded cover at the sprocket, which isconsidered a continuous oil leak problem. The cover has amachined out area in the corner. The corner contains a rubberstrip or rubber grommet that has to be replaced each time thecover is removed. RTV or a silastic sealant should be used withthe grommet to provide an additional sealant. It is importantthat the covers be properly installed to stop oil leaks.

Ie

CAMSHAFT ASSEMBLY

Reconditioning: The repair of the camshaft is not considered a "field fix." The camshaft should be taken to a shopthat has reconditioning experience.

The lobes are marked with the part number on one side andon the other side the word "governor end." It is important inany repair that during the process of putting the lobes on,attention is paid to which end is the governor end and whichend is the flywheel end.

The evaluation of the most economical way to recondition acamshaft should be of first consideration. If there is a badlobe that is close to the flywheel end, then the reconditioningprocess is easy. The old lobe is cut off with a torch and a newlobe installed. with a bad lobe near the sprocket end, thedecision should be to save the lobes since they are the mostexpensive part of the shaft. Under this circumstance first measure the lobe locations from the sprocket end. After removal ofthe sprocket, the shaft is then cut between cylinders and thelobes pressed off.

After machining a new shaft the lobes can be re-installedalong with a new lobe or lobes to replace the failed part. Alllobes should first be measured to make sure the interferencefit is approximately .004. The lobes are then heated by aninduction heater or in an oil bath to 450 0 to 500°F. The lobesare installed one at a time making sure to keep the correct endorientation. If a lobe hangs up it can not be heated for removal and then re-used because heat softens the lobe. Spacersmay be used between cylinders so the lobes can be rammed intoposition without hesitation.

Camshafts with a majority of bad lobes are reconditionedby hanging the shaft from the sprocket end and heating eachlobe and pulling it off the shaft. The re-Iobbing process isthe same as described above.

The cyclic problems associated with camshaft lobe androller wear required that operators and maintenance personnelvisually inspect the lobes and rollers on a periodic basis.Years of redesign of both the lobes and roller material as wellas the lubrication system makes the present set-up suspicious.It has been our experience that the lobes and rollers do notreceive adequate splash lubrication from the rocker arm area.In fact, several customers have solved their 825 lobe androller wear problems by adding an oil header along the outsideof the camshaft and installing orificed spitters on the lobes.Others have solved their problems by making sure that the rocker arm bushing side clearance is set properly and the rockerarm passage is clear so that adequate oil can gravity flow downthe valve train.e

L

CAMSHAFT ASSEMBLY

In addition, it is recommended that STP be poured overlobes and into the valve cover cavities prior to starting anewly overhauled engine. This will insure adequate lubricat10nfor those units without pre and post-lube pumps.

The hub assembly is not normally considered a maintenanceitem, but can be repaired in the same manner as the lobes. Thehub is doubled keyed and must be heated for removal after making dimensional checks to make sure it is re-installed at thesame position.

Installation: The hub is used for the mounting of the governor drive gear and the camshaft sprocket. The governor drivegear and camshaft drive sprocket are held in place by a retaining ring and capscrew. The next item to install is the governordrive gear, the sprocket, and the retainer ring. The capscrewsapply pressure to the retaining ring and hold the sprocket andthe gear tight against the hub during operation. After thecams~aft is timed, the caps crews are tightened and lockwired.

Prior to and/or after installation of the camshaft thethrust must be set. As shown in Figure 45, there is a camshaftmounting bracket located behind the sprocket (toward number onecylinder). This bracket contains the front cam bushing which isa bronze bushing flanged on the sprocket side. Immediatelybehind the bearing bracket bushing is a thrust coll~r. Thebearing bracket bushing is set against the hub, which is fjinto position with two keys and a tapered pin. The thrust clar is then adjusted to .004 to .006 thrust clearance. Thethrust collar is fixed to the shaft by two cup point setscrews. One may be locked after clearance is set. Then thecamshaft is rotated 180 0 and the shaft may be drilled to helpsecure the second.

The bearing bracket has an oil hole drilled on both sides,but only one hole goes all the way through to the bearing. Itis important that the oil hole that feeds the bushing be located outward, because there is a lubricating line that is tiedinto the oil galley on the bedplate that is tubed to the bearing bracket. The bracket is then fastened to the cylinder blockwith a bolt that goes through the block and is threaded intothe bracket. Once the bolt is tightened, it is wired to a wirelock screw, which is also a part of the cylinder block.

Chain tension is of major importance because too much tension will result in crankshaft distortion and/or camshaft bushing failure. Too little tension results in a chain failure.Chains have a tendency to stretch, so once they are set, it 1Snecessary to make periodic adjustments using the adjustableidler.

1

CAMSHAFT ASSEMBLY

The chain slack should be equal on both sides of the camshaft sprocket. Prior to checking chain tension, load one sideso all the slack is on the side being checked. The chain shouldbe able to move in either direction approximately 1/16-inchwith approximately 20 pounds force applied to a 20-inch 2 x 4.The adjustable idler should be adjusted so that there is a 1/16inch free movement in the timing chain, when measured betweenthe center of the adjusting idler bracket and the first toothengagement of the camshaft sprocket. When chains are adjustedthere is a tendency to rotate the camshaft; therefore, the timing should be checked after the tension is set.

Timina: The engine is now ready to be timed. The valveclearance and timing set points are included in the informationfurnished with each specific engine. The following is only aprocedure review and all valves are approximated for discussionpurposes.

For Inline Engines (Turbocharged)

(1 ) Adjust both the intake and exhaust valve tolash clearance between the rocker arm levervalve stern on number one cylinder.

.125 inchand the

(2) Bar the engine over until the pointer on the flywheel is indicating 40° before top dead centeron the intake stroke for #1 cylinder.

(3) Remove the lockwire and loosen the camshaft sprocketclamping ring capscrews. This permits independentrotation of the crankshaft and camshaft. With arachet and socket slowly rotate the camshaft clockwise (viewed from operating end) until the intakevalve just starts to open.

The opening of the intake valve can be determined byusing a dial indicator on the valve retainer.

(4) Next, tighten two or three capscrews on the retainer ring, which will lock the camshaft sprocket against the hub; the crankshaft and thecamshaft will then rotate together.

(5) Bar the engine in reverse direction 10° to 15°.Then slowly bring the flywheel down (normalrotation), with the dial indicator, recheck toverify that the intake cam is opening the intakevalve at the proper point on the flywheel.

--

( 6 ) For verification of proper timing, now make thesame check for the exhaust valve closing on #1cylinder.

101

CAMSHAFT ASSEMBLY

(7) For additional verification of timing the next st 0

is to check the cylinder adjacent to the flywheel .nthe same manner, check intake valve opening and theexhaust valve closing. This check will indicate anytwist in the camshaft and if the shaft is properlymachined.

(8) After verification at both ends of the shaft,bar the crankshaft over and tighten, pluslockwire all retaining ring capscrews.

(9) Check, as outlined above, on an annual basis.

The timing of V engines incorporates the same principlesas the Inline with a few exceptions. Since the number one onthe right bank fires first, the valve events are first checkedon this cylinder. Next, number one of the left bank is set.Verification is then checked on both banks at the flywheel endpower cylinders.

AUXILIARY END DRIVE

Figure 46 is a cross section of the auxiliary drive forthe overspeed governor and magneto on an Inline engine. Themain drive gear for these components is located in the front ofthe camshaft. As indicated, a stud holds the drive gear on thecamshaft, with shims 'between the gear and the end of the shaf'Shims are also located between the two driven components. Trbacklash can be set by the adjustment of these three sets oishims with the camshaft thrusted forward. Once the backlash isset, the housing must be dowelled in place.

r -------------II

! ..... ····_--1' .'I',:"':""""

~_Bi-nt-l:: MAG.~ 'f:

FIGURE 46AUXILIARY DRIVE

C-,xz.lASS

)'e

AUXILIARY END DRIVE

One thing that needs to be noted is that anytime a geardriven assembly requires shims after the backlash adjustment ismade, the mounting housings should always be dowelled. The samething would apply to the lube oil pump, that is gear driven offthe crankshaft, as well as any other assembly.

Overspeed Governor: There are several types of overspeedgovernors available for either pneumatic or an electric shutdown of the engine. One type is mounted to the control paneland is operated electrically off the ignition system. There isalso a magnetic pick-up arrangement that is installed in thegovernor. The one shown in Figure 46 is a mechanical overspeedgovernor and is the most common.

Overspeed governors are normally set at 10% above operating speed. So if a Superior 825 engine is operating at the max-'imum speed of 900 rpm, the governor is set to trip at 990 rpm.The device that is triggered by the governor is a micro-switch,which is available in either pneumatic or electric. The governor and gears are pressure lubricated from the engine lube oilsystem and then the oil gravity flows back to the crankcase.Being mechanical the governor's internal parts will wearthrough operation and vibration. However, experience indicatesthat it is more economical to completely replace the governorrather than reconditioning. Repair kits are available, however.

e Ignition System: The magneto drive arrangement, as indicated by Figure 46, is basically the same as the overspeed governor drive with the exception of a coupling. The coupling is agear type with a lock nut that is keyed with a cotter key. Inmounting the magneto, the flywheel is rotated to the specifiedfiring degree before top center on the compression stroke fornumber one cylinder. Next, manually rotate the magneto untilthe firing indicator is in number one position. (In all casesmagneto timing indicators and pointers are referencing the number one firing cylinder.) Then adjust the screw type clutch, byremoving the cotter key, loosening the nut and turning thescrew with a ratchet in either direction to align the magnetoin the firing position. This procedure adjusts the coupling tofit the magneto which is pre-set for number one cylinder firingindicator. After tightening the coupling screw, the engine isready to start.

By the use of a timing light the ignition timing can bechecked. If the timing is found to be off, it can be advancedor retarded by adjusting the drive coupling.

There are several ignition systems available, all of whichare acceptable. The most popular one today is the capacitordischarge type system, which is a significant improvement over

103

AUXILIARY END DRIVE

the breaker type system. In addition to the magneto, the ignition system consists of wiring, coils and spark plugs as shownin Figure 47. The sparkplugs are the one item that normallyrequires the most attention. The cost of labor makes it almostprohibitive to clean and re-gap plugs. It is more economical toremove, inspect and replace, if required with new spark plugs.

A proper spark plug installation check list would includecleaning the threads within the cylinder head, cleaning thespark plug gasket seating surface and torquing the plug to thespecified foot-pounds. Over torqued spark plugs create a numberof problems. Over torqued spark plugs increase the possibilityof the plug becoming galled to the cylinder head and during thenext removal, it could require that coils or thread insertshave to be installed in the head. The other problem caused byover torquing is that it may result in distortion of the endgap. Normally, over torquing will result in increasing the gap,requiring increased voltage from the coil.

It is recommended that both the primary and secondarywiring be replaced during major overhauls because it will deteriorate over a three to four year period. It is also importantto keep the coils free of dirt, oil, other foreign particlesand absent of paint. Paint is one of the major causes ofimproper grounding and damage or loss of ignition to engines.Each wiring connection should include a boot to protect it fromoil and water. If an engine is exposed to rain, then water covers, or some type of covering, should be installed to protectthe magneto and coils.

FIGURE 47

IGNITION

VALVE TRAIN

~ The valve train consists of the cam rollers, guides and~ush rods as shown in Figure 48. As indicated the roller isattached to an inner sleeve and a guide arrangement, normallycalled the cam follower assembly. The roller, which is surfacehardened, should be inspected periodicallY for wear and shouldbe checked for flaking. The roller width has been recentlyincreased to reduce lobe loading.

The pushrods are not of major maintenance concern unlessthey are bent by sticking valves. However, some of the olddesigned push rods had the ball end and socket end loctitedinto the tube. After extended operation, the loctite will comeloose and cause damage to the tubing. The proper push roddesign is one with welded sockets and balls to the push rodtube.

SVP[RCMAAQ[OtNOIHt ONlY

FIGURE 48

VALVE TRAIN

105

VALVE TRAIN

When the push rod is out of the engine, always make Sl'

that the roller and guide are free. If pushed to its maxinheight, the guide should free-fall back against the cam lobe.The rollers should be carefully inspected along with the camlobes.

The bracket that holds the cam follower assembly in place iscalled a yoke. Breakage is quite common due to over tightening.The yoke was originally made of cast iron and so sensitive tobreaking that it was impossible to go much beyond the crushingof the lockwasher that holds the yoke into place. Yokes are no~

available out of cast steel which eliminates the breakage problems.

Another part of the cam follower assembly fasteningarrangement is a sheet metal deflector that mounts on top ofthe yoke. The purpose of this plate is to decrease the amountof oil splashing against the side cover plate, so as to reduceoil leaks. It should be installed prior to assembling the pushrod and not in such a way that it can make contact with theside of the push rod.

The item to the far right of Figure 48 is for turbochargedengines only and is the gas injection valve push rod. The topof the push rod is ~lotted and recessed for the gas emissionvalve stem. The slot is used to adjust the gas valve cleara r

Engines with internal air starting have an addition c .1

lobe shown in Figure 48. This mechanism consists of an airstart valve push rod which is spring loaded. The push rod doesnot make contact with the lobe during normal operation.

CYLINDER HEAD

The power cylinder head, shown in Figure 49, is the heartof any four cycle engine. If maintained properly, the mechanicand operator are 60 to 70 percent down the road to having anengine which runs trouble free at design load and speed.

Superior engines have individual heads cast of an alloyiron with only two power valves, inlet and exhaust. In additic~

turbocharged engines have a gas valve located where the plug i~

in Figure 49, and engines with internal starting have an airstarting check valve.

The joint between the head and liner is sealed with a firErlng gasket. This area is made gas tight by torquing the headdown on the liner to approximately 400 foot-pounds. The air,fuel and exhaust connections are also sealed with gasketsbetween two machined surfaces.

1e

Ie

CYLINDER HEAD

The head is designed for jacket water internal cooling,which enters the head by way of a gasketed jumper from thecylinder block. The coolant water leaves the head on theexhaust side in order to be directly admitted to the exhaustmanifold.

With the advent of air cranking motors, the internal airstarting valve has been all but eliminated from new engines.They are, however, still in enough of the older engines to warrant discussion.

FIGURE 49

CYLINDER HEAD

The main problem associated with air start valves issticking open, making it impossible to start the engine.valve is actually an air check valve and is mounted as aof the combustion chamber. When pressure is applied fromair start valve lever, air is admitted through the checkto the cylinder. On a periodic basis the air check valvebe removed, cleaned and reseated.

Thepartthevalvemust

107

CYLINDER HEAD

Some of the older heads were also equipped with sniftervalves. The purpose of the snifter valve was to decrease thetorque required to bar the engine over. Past experience hasshown that the snifter valve did not help, so it was eliminated. The other misleading point associated with snifter valveswas that some customers felt they could remove the sniftervalve and fit the head with indicator cocks for firing pressureindicators or analyzers. This procedure is not recommended. Ifa firing pressure indicator is installed during operation thefirst thing that happens is the cavity (approximately l-inch indiameter and 6-inches long) fills with a combustible mixtureand at ignition, either creates a late burn or pre-ignition onthe next stroke. This can cause the head to crack in thesnifter valve port area and rupture an instrument. In addition,due to the long porting area of the snifter valve connection,analyzers are not recommended for power cylinder performanceevaluation on Superior engines.

There are many ·war stories· associated with the designand development of Superior heads. The head is such an important part of the total engine operation, it might be helpful toreview, the different success and failures that resulted intodays proven design. It is unfortunate, but the final conclusion took years of work and is not necessarily the answer forother 4-cycle engines since each engine type has its own designparameters and operating characteristics.

(1) The original cylinder head (prior to 1965) had ste 1

lited valves and seats. The valve stem was 4140 andthe valve seat was of a 45° design. When the turbocharged engine was uprated from 1000 to 1100 horsepower, the valve and seat life decreased considerablyto approximately 8,000 to 12,000 hours. Engines with75% to 100% load experienced excessive valve seatwear.

(2) This resulted in experiments with various types oflube oils and lube oil additives to increase valvelife. The success was minimum. The various changesincreased the valve and seat li~e to a maximum 16,000hours which was unacceptable.

(3) The next experiment was the various angles on thevalves and seats. First a 15° valve and seat wastried. A minimum amount of wear was experienced butthere was a tendency to loose the valves centeringability. When the springs brought the valve againstthe seat, the seating patterns were distorted. Excessive wear in the valve guides was also noted.

( 4 ) The valve and seat angle was then changed to 30°

, -',.4.9&£4£2 -

CYLINDER HEAD

centering capability was retained and the valve andseat wear was minimal.

(5) The material of the valve and seat was then changedto inconel, but no improved life was experienced.

(6) The next change that was made was to tighten up theclearance between the guide and the valve stem. Theclearance was reduced from .004 to .003 and the valvestern was chromed. These changes improved the centering capability even more and without guide wear. Inaddition, 1/2 to 1 percent ash content in the oil wasspecified. This change resulted in an ash build-uparound the power valves and seats, which acted as anadditional lubricant, and cut valve "sink" to a minimum.

In review the four items which improved the head life from8000 hours to in excess of 25,000 hours were:

(1) Change from 45° to 30° valves and seats(2) Reduce the guide to valve clearance from .004 to .003(3) Chrome the power valve stem(4) Run a 40-weight oil with 1/2 to 1% ash content

Valves. Seats. and Guides: It is worth stressing again,~e fact, that nothing but premium valves with 4140 chromed~tems, welded to a stainless steel head, and a hardened seat

area with stellite "F" should be used in Superior gas engines.The hardened surface of the valve is approximately l/8-inchthick. The reason this is pointed out, is that if the valve isre-ground many times it is possible to grind through the stellite and the valve will completely sink into the seat.

One other important note is that experience indicates thatrebuilt valves do not perform satisfactorily in Superiorengines. The concern is that a rebuilt valve core could havebeen damaged due to excessive heat. The welding process whichis used to re-stellite also generates an excessive amount ofheat. The results are a valve that is very susceptible tocracking. Anytime a crack starts, the gas acts as a cuttingtorch and a section of the valve is burned out.

Seats are also of seating surface. Often but the cost savings is a premium design, a stellite "F" or equal times a lessexpensive seat is available not worth the gamble.

Guides are made of cast iron and the 1.0. has a rifle boreswirled design to transmit lubricating oil down the valve stem.Some people have attempted to reduce the guide bore to obtain a

•~1IIIlJ.1I.1III.&III!Wl'i'.. ",e,"-,'?<,..'----------

109

CYLINDER HEAD

.002 valve to guide clearance. Experience indicates that .003is the minimum clearance with today's materials.

One method of indicating valve and seat wear lS to use thedimension from the valve stem to the machined surface on thehead of the properly reconditioned or new head as a referencepoint. With a depth gauge suspected valve sink can then be measured and compared with the reference dimension. The more wearthat is experienced, the greater the height between the valvestem and the cylinder head.

Springs: As indicated by Figure 49, Superior heads haveinner and outer power valve springs. The purpose of the outerspring is to bring the valve back tight against the seat andsecure it, so there is no floating. The inner spring alsoassists in this purpose, but the main purpose is to keep thevalve from falling into the cylinder, in the event the outerspring breaks or if the outer spring wears through the retainer.

The springs are wound in different directions as indicatedby the figure.

The spring ends are ground cut and the coils are shotpeened. Discussions with various spring manufacturers and experience have proven that shot-peening can double or triple thelife of the spring. One method of making sure a spring has bshot-peened is to inspect the ground cut end of the coil. Aspring that is not shot-peened will discolor by the heat ofgrinding. Shot-peening removes this burn look. Both springshave dampening coils on one end; the dampened end is installedagainst the cylinder head.

In the past few years there has been a spring designchange. During the inspection of engines, pieces of metal wereoften found on top of the head or down in the cam followerarea. Further inspection revealed that the broken pieces werefrom the ground tapered end of the spring coils. Originallythey were ground to a sharp taper and the fatigue rate at thepoint was high; therefore, the end would break off. On the newdesign the spring ground taper is cut back to the larger thickness area, so the breaking was eliminated. The proper identif~

cation of the new design springs is a yellow stripe on the outside of the springs.

Retainers and Keepers: The valve spring retainer is a heattreated item. When the retainer is removed from the assembly athorough inspection should be performed on the inside taper a~c

also the spring contact area. If wear is experienced in theseareas, it indicates an improper hardness and the retainer mus:be replaced. It's important to note that if the inspection 0"

CYLINDER HEAD

4Ilny part that has been heat treated reveals wear, it is an1ndication of either improper lubrication or insufficient hardness. The cause of failure should be determined and corrected.The power valve keepers are also heat treated. They are not ofmatched design but once they are mounted onto a valve and installed into a head and operated for a period of time, theywill establish an certain amount of seat-in. Therefore, ifkeepers are re-used, they should be kept in the same set asthey were removed.

Lubrication: Another feature of the valve mechanism designthat should be reviewed is lube oil control. On the intakestroke of a four cycle engine there is always a vacuum at theinlet valve port. The greater the clearance between the valvestem and the valve guide, the more oil that will be drawn intothe combustion chamber, so oil consumption will increase alongwith excessive carbon build-up. To help control excessivelubrication, an o'ring is installed on the intake valve stem.The o'ring is installed after the retainer and springs are compressed, just below the valve keeper area. After the valvekeepers are in place, the o'ring will rest against the bottompart of the keepers, forming a positive type seal around thevalve stem. Oil that comes over the end of the rocker arm provides splash type lubrication around the valve and the o'ringwill restrict flow directly down the valve stem.

~ The exhaust valve always has pressure around the port.More heat is also experienced around the exhaust valve stem andstandard clearances control the lube oil without an o'ring. Itis very important that anytime new valve guides are installed,that the inside diameter of the guide and the outside diameterof the valve be measured to be assured a clearance of .003. Ifthe clearance is too small galling of the chrome valve stem orsticking valves will be experienced; if it is too great, excessive oil consumption will be experienced.

Reconditioning: The reconditioning of the cylinder head 1Sof such importance that a complete review of requirements isneeded. The first thing that should be done is to examine thehead in the "as received" condition. A complete tear down isnext required, with only the seat and valve guides remaining.

The valve seat is next checked for wear patterns, theamount of wear and a determination as to whether the seat canbe reground or if it needs to be replaced. In most cases theseats are replaced if they show wear. The cost of labor associated with this type of repair warrants that when parts are inquestion, they are normally replaced. The labor associated witha failure and the lost production time should also be considered. In most cases it isn't worth the gamble to reuse ques-

~ionable parts.

111

CYLINDER HEAD

The seat has an interference fit in the head. The normalremoving tool is an old valve that has been machined down towhere it would fit up inside the seat. With the old valveinstalled up into the seat, a small bead is welded on the I.D.of the seat and then the old valve is used to drive the seatout of the head. With the seat out, always clean the cylinderhead seat surfaces and measure the head to be assured that thenew seat will have the proper fit. The interference fit of theseat to the head varies with the O.D. of the particular seat.Normally the interference fit is approximately .004. Some people are of the opinion that the more interference you have thebetter the seat will hold, but that is not true. If a seat isinstalled with an excessive amount of interference fit, combustion temperatures, the combination of too much crush, and thecast iron expansion can cause the seat to drop out of the headduring operation. If the head is worn due to repeated installation of seats, oversize seats are installed to maintain therequired interference fit.

The next item that should be checked is the guides. Theguides are of cast iron construction and have an interferencefit in the head. Anytime there is an interference fitted part,it is recommended that the part be frozen so it can be easilyinstalled. Seats and guides can be frozen in dry ice or liquidnitrogen. If these parts are installed without freezing, cracking of the part may be experienced. If the guides have to bereplaced, they can be pressed out. The guide flange is normallinstalled so it seats against the cylinder head. In some caSEhowever, the bottom side of the flange is not exactly perpendicular with the O.D. of the guide resulting in distortion ofthe guide bore. Some customers and cylinder head repair shopsroutinely install guides with a clearance between the guideflange and the cylinder head of approximately .005 to .010.Since the guide does have an interference fit and this practicedoes not upset the fastening of the guide, this procedure isacceptable. During the head rebuilding process the cylinderhead should also be hydrostatically tested and dye checked forcracks.

From time to time it becomes necessary to clean up thehead fire ring gasket seating surfaces. It is acceptable tomachine this surface, but it is important to maintain the depthdimension of the combustion chamber area in reference to thebottom machine surface of the head. If the combustion chamberdimension is not maintained, it will affect the crush on thegaskets and the overall block to head dimension which will create an oil leak problem. Record the amount of material removedand remember that an excessive amount of machining could eventually cause a cracked head due to weakening of the deck.

"----------

CYLINDER HEAD

~ Rocker Arm: The rocker arm assembly is also shown in Fig~ 49. and is of cast i.ron construction. The main wear partsJf the rocker arm assembly are the internal lever bushings,which should be checked during a major overhaul. The bushing isbronze and has two different sized oil outlets. The small oneshould be installed toward the valves and the large hole shouldbe installed toward the adjusting screw. This installation procedure is required to control the amount of oil flow.

The valve adjusting screw has a ball that fits down intothe push rod. Some push rod breakage problems are caused byvalves sticking in the open position and the ball ending up ontop of the push rod. During the next opening stroke of the camload cycle. the springs will completely collapse causing thepush rod to break or a piece break out of the push rod socket.

Some people are mislead by a stuck valve being hit by thepiston. The valve can be in the completely open position without touching the piston. Valves hit pistons only after the complete collapse of the springs.

Another item that should be checked is the flow of lubeoil to the rocker arm assembly. It is important that after acomplete overhaul the pre-lube pump be started. Then make surethat the rocker arm bushings are receiving oil. If the engine~oes not have a pre-lube pump. it is important that after

4IJart-up (3 minutes or less) the engine be shutdown to makesure that there is lubrication to all components. If elected.the upper valve cover lid can be removed during operation to beassured that lubrication is received at the rocker arm bushing.

The correct adjustment of the valves will be found withthe data furnished with the engine. Normally on gas engines,the intake valve should be set at .018 and the exhaust valve at.030. This is an initial cold setting. After obtaining normaloperating temperatures, the engine should be shutdown and thevalves adjusted hot. It is not recommended that valves beadjusted while the engine is in operation.

Installation: The head fit to liner is sealed by a firering gasket. There are two types of fire ring gaskets forSuperior engines. The old type is a wide gasket. approximately1/2-inch wide. The main purpose for the change to a more narrowgasket was to decrease the contact surface between the head andthe liner. so a seal could be maintained with less torque. Thetorque required for the original gasket was 450 foot-pounds andthe torque for the new gasket is only 350 foot-pounds. No majorproblems have been experienced with the narrow head gasket. Dueto some gasket breakage, some customers, however, prefer tocontinue using the wider gasket. Both styles of fire ring gaskets are available.

e113

.;1 ':

CYLINDER HEAD

In torquing the cylinder head to the cylinder block, analternating torque pattern or stepped sequence approach, sho~_J

be used. The head should be brought down slow and as even aspossible, so as not to create any distortion. Prior to torquingthe head, however, it must be just tightened down to where thehead nuts are snug against the head. Next start both the intakeand exhaust manifold capscrews, so the heads are lined up withthe manifolds. The cylinder head can be moved as much as 1/16thof an inch in any direction to accommodate alignment. If thisprocedure is not used, the manifold can be put into a bind,which can result in manifold cracking after start-up. The reader is also reminded of the previous discussion concerning theuse of the sponge rubber gasket between the head and cylinderblock, when the new metal backed elastomer liner gasket isused.

STARTING SEOUENCE

With the engine now properly reconditioned and assembled,it is appropriate to outline the recommended starting sequence.After making the checks discussed under the lubrication, coolant and air fuel systems, the recommended starting sequence isas follows:

(1) Bar the engine over to make sure it turns freely.

(2) Turn on the pre-lube pump and with side door cover:removed, check that all bearings are receiving proper lubrication.

(3) With the ignition "OFF" purge the unit with theexternal cranking motor at 40 rpm for approximately15 seconds.

(4) With the ignition "ON", start the cranking motor andas soon as the crankshaft starts to turn, open thefuel valve approximately 1/8 open. Continue cranking while further opening the fuel valve to a maximum of 1/4 open. The engine should fire and startat this point. As the engine gains speed, shut offthe cranking motor and open the fuel valve to thefull open position.

(5) While running the engine at no load for a few minutes, check the oil pressure, water pressure, etc.and with valve covers removed check assemblies forexcessive heat.

< ma4C

11-

STARTING SEQUENCE

(6 ) Shut the engine down and check main and rod bearingcaps by hand for hot spots.

If all items are found to be normal, the engine lS readyto be started and loaded.

NOTE: THE ENGINE AND COMPRESSOR SHOULD BE PROPERLYALIGNED PRIOR TO STARTING

COMPRESSOR

GENERAL

The compressor is a heavy duty compact design used normally in injection, air, refrigeration or propane service, andgas gathering. The Superior compressor is a reciprocating, separable compressor. The compressor takes its total horsepowerrequirements from a separate driver, normally an electric motoror engine. The driver transmits horsepower to the compressorthrough the rotating compressor crankshaft that converts rotating motion to reciprocating motion through the connecting rods

~nd crossheads to reciprocating compressor cylinder pistons androd assemblies; thus, transmitting compressor horsepower tocompress gas in the compressor cylinders.

Superior compressors are identified by a logical nomenclature that defines the unit - W62, W63, W64, and etc.

W - Model6 - Stroke of Compressor in inches2 - Number of Throws or compressor cylinders

Compressor cylinders are numbered beginning at the flywheel end of the compressor frame. Standing at the auxiliaryend (opposite the flywheel) and looking toward the flywheel thecylinder on throw closest to the flywheel on the right side isNumber 1, the next cylinder closest to the flywheel on theopposite or left side is Number 2. The numbering sequence continues, depending on the total number of throws or cylinders.Odd numbered cylinders are always on the right and even numbered cylinders are on the left. Some compressor frames arefurther identified by the letters "M" or "L" in front of theOW". These letters identify the compressor with a specific rodload. (Rod loads will be discussed later.) The basic rod loadsizes of Superior compressors are 27,500; 30,000; and 35,000psi .•

115

GENERAL

Figure 50 shows a typical two throw (W62) compressor. Thebasic or standard compressor will have the following components:

( 1 ) Compressor Frameconnecting rods,port equipment.

- The housing for the crankshaft,bearings, and other auxiliary sup-

(2) Crosshead Guide - The compressor crosshead runs onbearings or crosshead shoes on the crosshead guideslide and is the part that converts a rotating motion from the crankshaft to a reciprocating motionthrough the connecting rods.

FIGURE 50

TRANSVERSE CROSS SECTION

(3) Distance Piece - This part is shown in Figure 50and when required, is located between the crossheadguide and the compressor cylinder. Requirements fora distance piece depends upon a number of variablessuch as compressor cylinder class, application, and/or the gas being compressed.

(4) Compressor Cylinder - This is the component thatcompresses the gas. Figure 50 shows a typical sec-

11

GENERAL

• tional view of a low and high pressure cylinder.Themain components of the cylinder are the cylinderbody, piston, rings, rod assembly, suction and discharge valves, and rod packing case.

OPERATING PRINCIPLES

The basic principle of operation of a typical compressorcylinder, similar to the cylinders shown in Figure 50, isrelated to the type of gas to be compressed, the volume of gasthat is to be transmitted, and the suction and discharge pressure ranges that the compressor cylinder will be exposed toduring operation. Each application or each type of service willalways have a design suction pressure or pressure range and adesign discharge pressure range. This depends on the horsepowerthat is available for a given cylinder or a given compressorunit.

A basic operating sequence of a compressor cylinder wouldbegin with the suction stroke and the piston and rod at thehead end of the cylinder. As the piston moves toward thecranked on the suction stroke, the pressure inside the cylinderis less than suction pressure coming into the cylinder, and thesuction valves open. They remain open until the compressor pis-'-'on reverses direction and starts to compress the gas inside

~he cylinder. During the compression stroke the pressure insidethe cylinder exceeds suction pressure and the suction valvecloses. As the compression stroke continues the pressure insidethe cylinder will eventually equal discharge pressure, and thedischarge valves open. To pass the gas on to the discharge sideof the compressor, the pressure inside the cylinder has toexceed the pressure in the discharge line. Line gauges do notreflect the actual pressures that are developed in a compressorcylinder. Valve loss (pressure drops across each valve) contribute to the differential pressure between the inside ofcylinder and the discharge line. The sequence just described isreferred to as peak to peak pressures within the cylinder.

This sequence occurs in a very short period of time. mostcylinders, as the head end of the piston is in the suctionstroke, the cranked is on the discharge stroke. This mode ofoperation is called "double acting".

Compressor valves are in both the head end and cranked ofthe cylinder in quantities based on the cylinder class or working pressure. The valves are constantly in an open and closedmotion, completing a full cycle on each end of the compressorcylinder per stroke .

•117


Each compressor is designed for a specific application.most cases there are changing conditions, varying suction I ssure or discharge pressure are not uncommon. These condi t iOl'sare calculated based on all variables, so that the horsepowerutilized for each condition can be determined.

Figure 51 shows a common engine-compressor loading curvegiving horsepower, capacity, and variable volume unloader pocket data for a varying suction pressure, constant dischargepressure and for a specific cylinder class and diameter. Todetermine the amount of capacity that the compressor is capableof producing, at a given suction pressure, simply locate thesuction pressure on the curve and read up to the capacity. Whenthese conditions change, it might call for unloading of thecylinder, such as indicated. This curve shows the variable volume pocket (VV Pocket) opening position for a particular suction pressure. It also indicates compressor horsepower for eachVV pocket setting and capacity.

550

H:lRSEPQWER500

«

~450

w'"§ 400

2S'" 350'"w«

15 9 300~«0 100

'"<2>

0 C,.p,.CllY 7LL

~ 6>-

0l-

V

'""" 55 2~

4

Zw2; 3

~ 2>>

SUCTION PRESSURE PSIG 0

25 75 125 175 225

FIGURE 51


- Jt ,p i .. iJ.ilt46 Ii

IIIe

1,

6


The basic reason for using the variable volume pocket isto limit the amount of horsepower so as not to exceed the ratedload of the unit. The variable volume pockets add additionalclearance to the compressor cylinder. To unload or reducehorsepower and decrease capacity, clearance is added to the Inside of the cylinder by opening the VV pocket. This permitsadditional volume, of the gas being compressed, to remaininside the cylinder during the discharge stroke. In some casesit is necessary to add additional clearance by removing a headend valve or a crank end valve to unload a particular cylinderand keep it within the rated horsepower of the driver.

Figure 51 has a varying suction pressure for 25 psi gaugeup to 225 psi. As an example, at 125 psi read straight up tothe VV pocket opening. The scale to the right side indicatesthe inches of VV pocket opening required at 125 psig, withoutexceeding design horsepower. At 125 psig the VV pocket shouldbe opened to 3-1/2 inches. The next curve is the capacity curveand at 125 psig suction pressure the capacity is 7 standardmillion cubic feet per day. The top curve indicates horsepowerand at 125 psig suction pressure, the compressor horsepower is540.

As the suction pressure increases, it is necessary to moveover to that pressure and again read up in the vertical direction to change the VV pocket setting and determine capacity andmaximum horsepower.

Differential pressure, or compression ratios across thecylinder, also affects horsepower. As the suction pressureincreases, the horsepower increases until it reaches a ratiolimit. At this point the ratios are so small the compressoractually starts to unload. At 183 psig suction pressure Figure51, horsepower begins decreasing. It is then necessary to closethe VV pocket to increase capacity while still not exceedingthe maximum compressor horsepower. The important thing aboutloading curves, is that they should be made available to theoperating personnel so that they can operate the compressor atfull capacity, but still not overload the driver.

FRAME

As shown In Figure 52, the compressor frame is of heavyribbed cast iron construction that is supported at the top byprecision machined tie bars. The frame houses the main bearings, the crankshaft and it also is the base for mounting thecrosshead guides, cylinders, and end covers. The compressorframe is of a "un shaped design that is open at the top.

119

, ,1.1 1, L. I

FRAME

Prior to the installation of the crankshaft, the frameshould be inspected in the main bearing area. With the match~

marked bearing caps torqued and in their proper location, thebores can be checked for distortion. The bores should also bewirelined or checked with a straight edge to insure straightness. If there is distortion, due to bearing failure, the capcan be milled off, refitted and line bored back to a standardsize.

In most cases, frame bearings are the same as those usedin the engine. They are identical to those used in Inline engines except for the higher rod load compressor frames. Afterinstallation of the crankshaft, bearings, and torquing the caps,the precision tie bars are installed. It is important that theyall be installed at the same time and torqued evenly. Tie barsare not match marked to a specific location and should slipinto place. They are a close fit with a very small amount ofclearance and no force should be applied in the installation.Tight tie bars can create a stress down to the bearing saddles.When stressed enough, the frame will crack.~

OPERATING PRINCIPLES .L-, --_l::-. ()/

FIGURE 52

FRAME

FRAME

The compressor frame is usually grouted to a skid. Thestandard approach is to grout the driven portion of the enginecompressor package. After obtaining proper alignment betweenthe compressor and the engine, the compressor is normally resting on jack screws in a grout box. with all of the items properly tightened to the skid or the foundation, the feet of thecompressor can be grouted. The grout is not run completelyunderneath the frame, because the curing heat will cause thegrout to expand and it could crack the frame.

Figure 53 illustrates the oil seal rings and covers oneach end of the frame. On the coupling or flywheel end, thereis a stepped slinger type seal to keep the oil in thecrankcase. Normally the only time an oil leak is experienced inthis area is when the frame is overfilled with oil. At the auxiliary end, the shaft extends through the auxiliary cover. Someinstallations utilize this shaft as an auxiliary drive and ithas a seal around the shaft which is bolted to the rear housing. This shaft may also be used to drive various types of analyzer equipment and is a convenient place to take compressorrpm with a hand held tachometer.

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AUXrLIAl'N

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FIGURE 53

LONGITUDINAL CROSS SECTION

121

FRAME

The last assembled component of the frame is the cover.is normally made out of aluminum and used as an access cover.The cover is vented to atmosphere. Due to the possibility ofgas leaks around the packing glands which can escape and enterthe compressor frame, it is recommended that the vent be pipedoutside if the compressor is located in a building.

CRANKSHAFT

The compressor crankshaft, shown In Figure 54, is a heavyduty forged steel shaft. It is ground in the same manner as theengine crankshaft and has highly polished journals. It is rifledrilled from the main bearing up to each connecting rod bearing. The number of throws and main bearings depends on the number of cylinders or frame size. As an example, a two throwframe will have two main bearings and two connecting rod bearings.

The same inspection procedures apply to the compressorshaft as the engine shaft. Anytime a bearing failure occurs,always check the shaft very carefully. If there are anyscratches or heat discoloration, in most cases the shaft willrequire conditioning after being magnafluxed or dye checked. Acomplete inspection should be performed each time there is anyquestion about whether the shaft has experienced some type ofdamage.

Figure 54 shows a steel gear on the auxiliary end of theshaft which has an interference fit. On the coupling end is aslinger ring seal that is also an interference fit. Both ofthese items have to be heated to remove them.

FIGURE 54

CRANKSHAFT

1

CRANKSHAFT

The compressor crankshaft like the engine crankshaft canbe repaired by chroming. It is recommended that the shaftalways be returned to standard deminsions even though undersized bearings are available. As with the engine crankshaft, itis best to have a good core and not weld on the shaft. Ideallythe shaft should be ground down and chromed back to standard,with 0.020 chrome plating as maximum.

Figure 54 also shows two connecting rod journals, side byside, between two sets of main bearings. Under balance, therewill be a discussion on balancing a typical compressor. No. 1cylinder should be balanced to No. 2 cylinder and No. 3 cylinder should be balanced to No. 4 cylinder. New style compressorshave counter weighted crankshafts, as opposed to older stylenon-weighted shaft, shown in Figure 54.

CONNECTING RODS

The connecting rod as shown in Figure 55 is a heavy dutyforged rod. It is the same basic design as in the engine with arod bearing bore and a piston pin bore. Lubrication passes fromthe rod bearing to the pin through a rifle drilled passage. Rodbearings are identical to the main bearings and are interchangeable, in most cases, with the engine main bearings. The

4Itin bushing is a steel backed, trimetal type bushing.

Anytime a connecting rod is out of the compressor, alwaysremove the bearings and the bushings. Completely inspect andmeasure the rod bearing bore with the bolts properly torqued.This will determine if it is out of round or egg-shaped. Repeatthe same procedure with the pin bore. Also check the rod forstraightness to make sure there is no bending in the rod. Ifthe rod bearing bore is found to be out of round, in mostcases, milling off the cap at the parting line and re-boringthe rod to standard size is an acceptable repair. Cautionshould be used anytime there is any amount of discoloration dueto extreme heat, and it is not recommended to rebuild any rodthat shows heat damage. Torquing is critical. Always use thespecified amount of torque and apply the proper torque sequencing steps in increments of various foot pounds until the fulltorque valve is reached.

During the inspection of the pin bushing there is one particular item that must not be overlooked, that is excessivewear on one side of the bushing. When experiencing wear,whether it be on the crank end side or the cylinder side, it isan indication that the problem might be associated with rodreversal. \The bushing 1.0. is grooved with an angle pattern toinsure a maximum amount of lubrication between the bushing and

123

CONNECTING ROD

FIGURE 55

CONNECTING ROD

pin. Whenever an operating condition requires the unloading ofa particular end of a compressor cylinder and it is necessaryto either pull a suction valve or unload the head end with theVV pocket, the gas pressure on one side of the compressor piston will have a tendency to hold the pin against one side ofthe bushing. This constant contact between the pin and thebushing will reduce lubrication and cause excessive wear whichcan result in a pin bushing failure. The problem in most casescan be av~ided by maintaining the engine speed above 750 rpm.This enables the inertia weight force to offset the compressionforce, thereby, maintaining clearance and allowing adequatelubrication to the pin bushing.

CROSSHEAD GUIDE

The crosshead guide is located between the compressorframe and the cylinder. Crosshead guides come in variouslengths and are of cast iron construction. Figure 56 shows atypical crosshead guide having two side cover plates on eachside. The larger cover plate, closest to the frame, is theaccess to the crosshead. The small cover plate is the access

1

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CROSSHEAD GUIDE

~to the rod packing and wiper packing glands. In a lot of casesthe small cover is removed so that operators can check forpacking leaks or wiper packing leaks. The crosshead guide hasoil drains and vents which are always vented outside the building.

Different length crosshead guides are required for different weight crossheads and for special sizes of compressorcylinders. Large cylinders make it very difficult to get inbetween the frame and the cylinder, so a longer guide may beused. The smallest crosshead guide is only fifteen inches longand the longer guides do help when it comes to getting to thevalves on the crank end side of a large cylinder.

Crosshead guides have limitations in the size of crossheads that will fit. In some cases, it may be necessary tochange the crosshead guide in order to change from a 50 to a150 pound crosshead.

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FIGURE 56 1pJCROSSHEAD GUIDE

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125

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CROSSHEAD GUIDE

The crosshead guide is mounted to the frame with a thinpaper gasket between the guide and frame. Care should be taketo insure that gasket surfaces are clean. The same care wouldapply to the cylinder end. The guide fit at the frame and atthe compressor is precisioned machined for alignment. In addition, the crosshead guide to frame has two dowel pins, one atthe bottom and one at the top, to frame has two dowel pins, oneat the bottom and one at the top, to properly locate the guideinto position. The cylinder side has a machined lip that thecylinder fits over for alignment.

At the cylinder side of the crosshead guide there is apedestal support. It is normally referred to as the "cold support," and between the support and guide there are shims tomaintain cylinder and rod alignment. The basic reason for thecrosshead guide support is to decrease the amount of stressthat could develop at the frame due to the guide and cylinderweight. If not properly supported, distortion occurs and thereis the possibility of experiencing cracks in the frame.

CROSSHEAD AND PIN

A typical crosshead is shown In Figure 57 and is a ductileiron casting. The crosshead is available in different weightsfor balancing opposing cylinders and has replaceable shoe typebearings on the top and bottom. Shims between the crosshead arshoes are not recommended. The crosshead and shoes are desigrfor a fixed clearance within the crosshead guide. Some of thelow rod load frames have crossheads without replaceable shoes.Crossheads are lubricated on the top and bottom from the framelubrication system.

Excessive wear of the crosshead guide slide areas mayoccur when the clearance between the guide and the crosshead isexcessive. In some cases, replacement shoes will not correctthe clearance. The guide slide area must be built back to astandard or the guide must be replaced.

Fastening of the shoes to the crosshead is accomplished bytwo methods, which depend on the size of the crosshead.Crossheads of 100 pounds and above have a threaded casting andnylock allenhead screws are used on each end. Figure 57 showsthe screw and elastic stop nut method of fastening on a 50pound crosshead. It is recommended to replace the small 1/2inch elastic stop nut each time it is removed. It is alsoimportant to have the proper length screw, to insure full contact with the elastic nut. When these screws come loose, theycome in contact with the guide and groove the guide slide

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CROSSHEAD AND PIN

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FIGURE 57

CROSSHEAD & PIN

area. This particular problem resulted in a design change whichresulted in lengthening the allen head cap screws and addingself locking nuts.

~ The crosshead pin, Figure 57, is tapered on both ends to~t the crosshead. There is a cap on each side of the pin and athrough bolt. The large cap actually pulls the taper pin intoposition and it is torqued to the proper value to fasten itpermanently and then the bolt is secured with a wirelock screw.The newest design has a through bolt with an elastic stop nut.It has to be properly tightened to insure that the pin issecured. To remove the pin from the crosshead, reverse the capsand the large cap can be used as a pulling tool. It is important to note that since this is a taper lock pin, the pin cancome loose all of a sudden and pop out of the crosshead fastenough to injure a mechanic. So remove the pin slowly and donot stand in front of the pin. If necessary, tap it with abrass hammer to assist with slow removal. The pin is a hardenedheat treated alloy steel and normally will not show wear, butit should be measured each time it is removed.

The crosshead bushing has incorporated helical oil grooveson the I.D. to aid and retain the lubrication. The load appliedto the crosshead pin bushing is developed from the forces ofinertia of the reciprocating masses and the forces resultingfrom compression of gas in a cylinder. The inertial forcesdevelop as a result of the weight of the piston, rod andcrosshead assembly being in reciprocating motion. Many problemsassociated with a failed bushing have developed in the past

4Itcause of operating under non-reversal loads.

127

CROSSHEAD AND PIN

In order to properly lubricate the bushing a load reversalmust take place on each stroke. When the load is applied to oneside of the bushing some finite amount of clearance develops onthe opposite side. This clearance is filled with oil lubricating and cooling the bushing. In order to lubricate and cool theother side of the bushing a clearance must develop there also.A reversal in the direction of application of the load mustoccur for this to happen. The duration of the reversal must besufficient to completely fill the clearance space with oil.

If a single acting cyl{nder configuration is required onSuperior compressors it is recommended that you operate thecrank end which has a smaller piston area, will produce asmaller gas load, and increase the reversal.

Some of the factors that will affect reversals and have atendency to produce non-reversals are:

(1) High compression ratios.

(2) High cylinder pressures. This normally involves highgas load and small cylinder bores.

(3) Low volumetric efficiencies. (VE). This results fromhigh clearances particularly when clearance is addeddeliberately for unloading purposes.

(4) Slow speed operation in conjunction with other factors such as small bores and high cylinder pressures.

(5) Single acting operation. Single acting head end isalways more susceptible to non-reversals than singleacting crank end operation.

The piston rod nut which is also shown in Figure 57 maycause piston rod failures. The threaded bore in the crossheadis where the compressor piston rod fits, and then is locked inplace with the piston rod nut. Piston rods will break at theflange of the crosshead if the crosshead threads are not perpendicular with the machined face of the crosshead. When thepiston rod or the balance nut is torqued, the rod is actuallybeing forced or cocked enough to create breakage. The crossheadshould be checked to insure that the threads are perpendicularand that the mating surface for the balance nut is clean andtrue. The balance nut should also be inspected. Check thethreads in the nut to make sure they are perpendicular with themachined surface on the nut. This can be done by dial indicating each piece, or by blueing the contact area of thecrosshead.

128

---------_a4�'4�'l4.. i_4l11111_.:. ••••••••••••••••

PISTON AND ROD

Compressor pistons vary in size from 2-3/4" to 26-1/2" and.re either an integral part of a piston rod or a separate casting of iron or aluminum. Size and material depend upon theapplication. Figure 58 shows a typical piston and rod assembly.The larger the piston the lower the pressure. A piston that is26-1/2 inches in diameter would normally be operating with discharge pressure below 150 pounds. Pistons of 4-inches in diameter and smaller, are usually integral with the rod. Normally,pistons 4-inches through la-inches are cast iron and 10-1/2inches through 26-1/2 inches are aluminum.

Wear is usually experienced in the compression ringgrooves and/or rider ring groove areas of pistons. This iscaused by the piston reciprocating motion. Each time the pistonchanges direction, piston ring slap occurs. The greater theclearance between the ring and the ring land the greater thewear. Once the wear begins, it continues to the point that pistons must be replaced. In some cases pistons can be remachinedin the ring groove areas and oversized rings can be installed.

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FIGURE 58

PISTON, ROD & PACKING

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129

PISTON AND ROD

This problem is much more prevalent in aluminum pistons. Castiron pistons sometimes experience scuffing on the 0.0. of thepiston when the piston comes in contact with the cylinderliner. Ring groove wear on cast iron pistons is normally minimal because the ring materials are softer than the cast iron.

Compressor rings and/or rider band material selection willvary with customer preference, operating conditions, and thegas being compressed.

Some examples of piston rings and rider ring materials areas follows:

BRONZE

THERMOPLASTIC

LAMINATES

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( 1 )

( 2 )

(3 )

( 4 )

TEFLON

( 1 )(2 )

( 3 )

Low temperature micarta-cotton based resinphenolicHigh temperature micarta-asbestos based resinphenolicLow temperature moli-di cotton based molydisulphideHigh temperature moli-di asbestos based molydisulphide

Carbon graphite filled teflonGlass filled teflonGlass moly-disulphide filled teflon

Temperatures often referenced with the laminate type ofring material refer to compressor cylinder operating temperature. Low temperature rings are good in applications up to275°F. High temperature rings are good in applications up to375°F.

Piston rods vary in length depending on the compressorcylinder classification. Rods are normally of a SAE 4140 material with and without rolled threads on the crosshead end. AllSuperior rods are flanged at the piston area diameter variesfrom 2-1/2 inches to 4-1/2 inches. On applications where thepiston is aluminum, the rod nut seats against a steel washerthat acts as a flange on the head end of the piston. This isrequired to give a hard seating area for the piston nut when itis torqued. Threads on piston rods with high rod loads (30,000to 35,000 pounds) are normally manufactured with rolledthreads.

131

gause

PISTON AND ROD

Rods can also be manufactured with sophisticated hardeningprocedures in the packing area. Typically, a rod could havetungsten carbide in the packing area to improve wear resistance. Piston rods are normally 2 or 2-1/4 inches in diameter.During inspection of a piston rod, one of the first things thatshould be checked is the threaded area that screws in thecrosshead, to make sure no threads are damaged. Then inspectand measure the area that normally runs in the packing to makesure that it is not worn to the point that there could beexcessive blow-by. In the case of bad thread or a worn rod,replacement of the rod is required. In installing the rodthrough the pressure packing and wiper packing, thread protectors are used around the threads to push the rod through thecase without damaging the packing sealing capability.

Rod load limits exist on all Superior piston rods and aredependent on several factors including piston and rod diameter,stroke, RPM, reciprocating weight, clearances, valve losses andsingle or double acting conditions. Several years ago ~hite

Superior developed a program to evaluate rod load. This programis used to size compressor cylinders for specific applications.Calculates the maximum compressive and tensile rod loads usingthe operating pressures external to the cylinder to obtainexternal rod load. External rod load is a close approximation

f the actual rod load and indicates whether a reversal exists.defining a limit for E.R.L. you can also determine if the

,agnitude of the rod load exceeds the design loading capabilityof the machine. This limit is set somewhat below the actual orinternal rod load which is based on pressures internal to thecylinder. The use of external rod load limits enables the customer to periodically examine their rod loads as operating conditions change. The rod load limit is provided for each Superior compressor and can be found in the front part of the compressor section of the parts manual.

PACKING

Packing can be classified into two types: pressure packingfor the compressor cylinder and wiper packing for the compressor frame. Figure 57 shows both of these types and gives a goodcross section of the pressure packing and the wiper packing.Note that the pressure packing assembly is bolted to the cylinder itself and the wiper packing assembly is bolted to thecrosshead guide. The pressure packing case has either a gasketor o'ring on the piston side that seals it against the cylinderbody. It is important that the bolts or cap screws are of theproper length in order to tighten the packing to the cylinder.If the bolts are too long they bottom out and then gas leaksaround the outside of the packing case. Anytime the packingcase assembly is leaking on the outside of the case, gas leaks4Ite going to be experienced externally to the crosshead guide

4i.

131

.. ;~,

PACKING

chamber. When the packing case leaks internally, it is ventecoutside the building through vent lines. The main purpose ofthe pressure packing is to seal the gases from escaping fromcompressor cylinder.

The wiper packing's purpose is to retain the lubricatingoil inside the compressor frame. Each time the piston rod movesto the outward stroke, the wiper gland is scrapping the oil offthe rod and returning it to the compressor frame.

There are several different type packing materials available. Some of the most common are bronze, moly-disulphide,teflon, thermoplastic, and cast iron. The material selecteddepends on the type of service and customer's preference.

It is recommended that the packing case be completelyremoved from the cylinder for inspection or repair. Some peoplehave tried to repair the packing assembly in place and in mostcases they end up causing damage to the packing or improperlyre-installing the packing. It is very important that prior todisassembly of the packing case, that it is marked by numberingthe individuaL sections so it can be reassembled in the samemanner. After disassembly of a packing case one of the mainitems to check is the diameter of the individual gland boresand the depth of th~ bores. A packing case that has run forawhile will show wear. What is required is to bring these cav'ties back to standard by machining and lapping each one. Thi~

applies to pressure packing as well as the wiper packing.

Most packing cases are oil lubricated - the only exceptionbeing non-lube applications such as a liquified natural gasservice. Some packing cases are both oil lubricated and watercooled. Water cooled packing cases will contain small o'ringsto shield around the water passages from one gland to theother, so extreme care should be exercised when assemblingthese parts.

The other item that should be noted during reassembly ofthe packing cases with new packing is that it is important thatthe type of packing be noted for each gland. There are doubleacting, single acting and wiper packing rings. It's importantthat these packing rings face the correct direction and areinstalled in proper sequence, so the packing case performs asit was intended.

CYLINDER BODY

~ Compressor cylinder sizes range from 2-3/4 to 26-1/2 inch.The cylinder body material varies from cast iron, to caststeel, to forged steel. The cylinder material depends on theoperating pressure required. Normally from vacuum up to 1500psi, cylinders are cast iron; from 2000 to 2500 psi, cylindersare cast steel; and from 3000 to 7500 psi, cylinders are forgedsteel. Some cylinder bodies are equipped with replaceable liners as shown in Figure 58 and some are not. The disadvantage ofa cylinder body that does not have a replaceable liner is thatit is very difficult to repair the cylinder, especially whenthere is not enough casting to machine out for a liner. Thesize and the class of the cylinder will determine if a linercan be installed. The most common method of repair of a cylinder that cannot be relined is to bore the cylinder out to thenext standard size or to the next fractional dimension andinstall oversized rider rings, piston rings, and in come cases,pistons.

Damage or wear to a cylinder liner simply requires replacement of the liner. Cylinder liners are available in twodifferent configurations, depending on the cylinder class.Standard 0.0. - 1.0. liners (without a flange) are held inplace with an interference fit. Flange type liners normallyhave a minimum clearance between the cylinder body and the 0.0.of the liner. Flanged liners are held in place by the cylinder

~ead torqued against the flange. Interference fit liners nor~ally have to be removed by machining and then the new liner is

frozen so that it can be pressed in, thus maintaining the proper interference fit. Most interference fit liners have to bemachined in the 1.0. after installation.

Any time a liner is removed from the cylinder, always makesure that the cylinder bore is clean and true. The bore shouldbe measured to insure the proper liner to body fit. Sometimesreplacement liners are not finish machined on the 0.0. Makesure the cylinder bore has been cleaned and that the replacement liner is machined on the 0.0. to get the proper interference fit between the liner and the cylinder.

Each cylinder has a water jacket built into the cylinder.The operating pressures and temperatures will determine therequirements to circulate cooling water through the cylinder orto have static cooling. Static cooling is accomplished by filling the cylinder water jackets with a liquid such as lightweight oil or antifreeze utilizing an expansion reservoir and avented cap to allow for expansion at normal operating temperatures.

133

j'1},

.,

CYLINDER BODY

FIGURE 59

CYLINDER BODY

Figure 59 show$ two passages at the bottom, which areindicator cock passages for both the crank end and head end.These passages are normally used for operating compressor an~

lyzing equipment. Instrumentation can be hooked up to thesepassages that will indicate pressure and volume from whichhorsepower can be calculated during operation. The indicatorpassage is drilled into the center, exactly mid-point on thevertical plane, and it can also be used to determine the totalvolume of the cylinder by use of a liquid.

One of the most important items associated with the compressor cylinder assembly is to properly set the piston tocylinder clearances. After installing a piston and rod completewith rings, it is then time to set the compressor piston clearance. First rotate the compressor unit until the crosshead isat its full inward position. Verify this by using a dial indicator. Next install the piston with the balance nut on thethreads to lock the piston rod to the crosshead. Screw the piston in until it touches the crank end side of the cylindersrear head. At this time install the cylinder front head andtighten several of the cylinder head studs to secure the headin its normal position. Rotate the compressor unit until thecrosshead is at its full outward position, again by using thedial indicator to indicate that position. -Then with the use ofa feeler gauge, measure the total cylinder clearance. The totalclearance will normally be .180.

CYLINDER BODY

One-third of that total clearance should be placed on thecrank end and two-thirds on the head end or .060 on the crankend and .120 on the head end. Next remove the front head,rotate the compressor unit again until the crosshead is at itsfull inward position, and properly adjust the crank end side ofthe piston to get one-third total clearance or approximately.060. After setting the crank end clearance lock the piston rodor balance nut to the crosshead. Then recheck the head end. Theprimary reason for the 1/3 and 2/3 setting is to compensate forthe rod expansion under normal operating temperatures. The piston and rod assembly will grow toward the head end and theclearances will become approximately equal during operation.The actual clearances should then be recorded for future reference.

PLATE VALVE

GENERAL

The plate valve, as discussed in our basic operating prin~

ciples of compression, is nothing more than a spring loadedcheck valve. As shown in Figure 60, the major components of acompressor plate valve, are the guard, seat, plates, springs,and the valve bolt. The valve guard is the housing for the

~prings and the guard is machined to a total lift depth accord~ng to the valve plate thicknesses and the required lift for a

particular application. The valve plates are held tight againstthe seat by the valve springs and the only time the valveplates will activate is when the pressure on the spring side ofthe valve is lower than the pressure on the seat side. Gas flowis always against the springs.

The valve plates are available in either stainless steel orthermoplastic. Both come in various thicknesses. The most common stainless steel plate thickness would be the .082. Thethermoplastic valve plate is available in .082 and .125 inchthicknesses.

The valve springs are wire coiled and shotpeened. They dohave a cast iron spring seat insert that makes contact with theplate instead of the end of the spring coil. The spring and theseats are color coded and it is very important that the properspring be used in a specific valve assembly at all times. It isnot unusual to use a different spring in the suction valve versus the discharge valve of the same cylinder. Springs come invarious sizes and each size will have various spring tensionsavailable. Just because a spring is of the same size it doesnot necessarily mean it is the same tension; that is the reasonsprings are colored coded.

135

I:.;GENERAL

The valve assembly is held together either by a stud or abolt. The valve will have a center sleeve to properly locatethe guard with the seat. The valve bolt will also have a gaskt~

underneath the head of the bolt which must be replaced any timeit is necessary to disassemble the valve .

VM...VE

•i

,"

RECONDITIONING

FIGURE 60

PLATE VALVE

After removing valve assemblies from a compressor andbefore disassembly of the valves for reconditioning, it isimportant to remember that the condition of each component bedocumented, whether it be worn valve springs, spring seatsplates, spring wear patterns or damage to the guards and seats.Valve seat surfaces must be free of nicks or cracks of anytype. One of the major problems in reconditioning compressorvalves, is that they are taken down, cleaned, the seat surfacelapped and no checks are ever made associated with the totalguard lift depth. It is important if the guards require to bemachined, that the design lift, with the specified plate thickness, be maintained.

Compressor valve guards should be inspected in the ringtravel area, checked down in the spring holes for wear patternsor excessively worn areas, valve seats should be inspected eventhough there are no signs of excessive wear or visual scratches.

RECONDITIONING

~ The seat should be lapped on a valve lapping machine toinsure a true flat surface. A valve seat that does not have atrue seating surface will bend the plates in operation and ifstainless steel type plates are in use it could create breakagebecause of a distorted seat. During this lapping processinspect the seat and the actual area that contacts the plate(small ridge). The main seating surface has a groove machinedin it. This ridge pattern assists in cooling the valve duringnormal operation. The gas that is flowing over the ridge willcool the valve quicker than having a common flat surfacethroughout the whole plate area. During the lapping processthis ridge could roll up on top of the seat and get b~tween theplate and the seat, therefore cracking the plate. If extensivelapping is required, it might be necessary to file off thissharp edge.

Valve failures are sometimes incorrectly solved by installing a thicker plate. Whenever thicker plates are installed, the original assembly design is changed. The one thingthat must be kept in mind is that the proper lift must be maintained. As an example if it is necessary to convert from an.082 inch thick plate to a .125 inch thick plate, then theguard must be machined to allow for the thicker plate and alsoto maintain the original lift. By decreasing the lift of thevalve assembly the pressure drop across the valve is increased,

~he capacity decreased, or the horsepower required to flow the~ame amount of gas will increase.

One of the most common items noted in repairing compressorvalves is spring failures. There are a lot of springs on themarket, some of which are properly designed, but many of whichare not. It is important to have the correct spring, shot peenedand with the correct spring rate, in order to have the compressor plate valve operate efficiently and with minimum failures.

Anytime continuous valve failures are experienced, goodrecords should be maintained so that the failure can be analyzed. It is also important that if the same failure occurseach time with a particular valve plate, this informationshould also be recorded. For example, if the outer valve plateis breaking on the same valve constantly, it indicates thatthere could possibly be a gas pulsation problem. The main purpose of the spring is to return the plate to the valve seatseating surface and to hold the plate against the seating surface so that it does not flutter or bounce back. This is whythere are the various spring tensions available. Ideally, thevalve plate should return to the seat and stay there. If gaspulsations are experienced, then the plate would have a tendency to bounce off the seat. This can usually be corrected byusing a stronger spring. Sometimes it might also dictate a

~eqUirement for orifice plates in the gas piping or pulsation

laiN

137

"

.~

RECONDITIONING

bottles to reduce pulsations. Emphasizing once more, it isimportant to keep proper records of valves because it will helIn determining the corrective action to be taken.

During the repair of the valve seat or the valve guard itis very important to maintain the total thickness of the valveon the flange area because every time the seat is machinedand/or lapped the total thickness of the seat is decreased. Asan extreme example, it could be possible to decrease the totalthickness of the outer flange of the valve, where the gasketfits, to the point that the valve cap would actually sitagainst or rest against the compressor cylinder body. In thissituation, it would not enable the mechanic to torque the valveproperly into place. The valve to cylinder gasket should bereplaced each time the valve is taken out and the seating surface should be checked to insure that there is a good surfacethat will enable the valve to seal from the cylinder compression chamber. The gasket is available in various material. Thedifferent materials are copper, aluminum, and different gradesof soft cast iron. Again, it depends on the type of service.One thing that should be noted is to never use any type of copper gaskets, bronze rings or bronze packing in a sour gas (H2S)application because the gas will attack the copper and bronze,which will result in a lost seal.

RETAINER

The valve retainer or chair is just a distance piece orspacer between the valve assembly and the valve cap that holdsthe valve assembly in position. The valve retainer should beinspected on a periodic basis. From Figure 59 it can be seenthat the valve retainer has a set screw in the side, on the capside. The only time the set screw is used is when the valve ison the bottom or discharge side of the cylinder.

After installing the valve retainers in the dischargevalve pockets, simply snug the set screw against the cylinderwall in order to hold it in place while installing the valvecap. Do not over tighten - just snug it up enough to hold thevalve retainer in place so that the valve cap can be installedproperly. Set screws located in the suction valves or the topvalves in the cylinder should be removed and discarded becausethey are not required and sometimes they come loose, fall downnear the valve and/or end up in the gas stream.

li. .44 ,l,_,LUxaa&ECSll ta"

130::

VALVE CAP

4It The valve cap will normally contain an o'ring. The o'rings~re supplied in two different types of materials, depending onthe operating temperatures. Normally the suction valve willhave a neoprene type rubber o'ring and the discharge will haveviton, because of the higher temperatures. The viton can withstand a much higher temperature than the neoprene. Mixing upcap o'rings and using a suction valve o'ring in place of a discharge valve o'ring will cause a leak. In some cases customersjust buy discharge o'rings and use them in both the suction anddischarge valves. The viton o'ring, or the discharge o'ring,will be marked with a white paint dot or stripe on the outeredge of the o'ring. It is recommended that the o'rings bereplaced each time the valve cap is removed. It is very important that the valve cap be torqued properly when reassembled.

UN LOADER

HEAD END

""--FIGURE 61

HEAD END UNLOADER•

As reviewed under operating principles, when conditionschange such as suction and discharge pressures, cylinder unloaders are used to control compressor horsepower and/or volume. Normally horsepower and volume are controlled by enginespeed; however, under overload conditions and volume requirements outside the driver speed range, unloaders must be

tlOyed. Figure 61 is a cross-section of a manual type cylinhead unloader which is most commonly referred to as a vari

e volume pocket (VV pocket). As indicated, the assembly consists of a piston, an operating screw, a locking handle and ahandle which turns the screw to set the piston position. Ascale indicates the amount of opening in inches

139

....,

1

Ir•~

HEAD END

A requirement to decrease capacity, or load, on the compressor necessitates an increased cylinder head end clearanceby backing out the piston and volume (clearance) is added tothe head end of the cylinder. To increase capacity the screw lS

turned so as to move the VV pocket piston in. Normally, thescale is graduated from 1 to 7 inches.

The main items requiring maintenance are the operatingscrew and piston. The piston is subject to a pulsating forcewhich results in fatigue breakage of the screw at the step downfit for the piston. Other maintenance items include the periodic replacement of the packing around the operating screw, whichis a rope type packing, held in the gland by a flange.

A new design for the operating screw and VV pocket pistonhas eliminated most of the maintenance problems. This changeincorporates a flanged operating screw with a series of studsthat extend through the piston with lock nuts on the cylinderside.

There are also pneumatic cylinder head unloaders that areof the same basic design as the one shown in Figure 61.

The differences in design is that the piston is positionedeither in the open or closed position by a pneumatic actuator.

VALVE

Figure 62 is a cross-section of a pneumatically operatedvalve unloader. This type of unloader is used on a suctionvalve and makes the valve "in operative" by holding the platesdown. The unloader is activated by pressure being applied tothe top piston, driving the fingers down and pushing the valveplates away from the seat. After the pressure is removed, aspring on the backside of the piston lifts the fingers back offthe valve plates. There is also an assist spring on the bottomof the fingers to give additional force to bring the unloaderto the de-activated position.

The unloader fingers on this type of design, vibrate dueto cylinder pulsations and breakage is common. Older designsattached the fingers directly to the actuating shaft without acentering bushing and tended to bind up because of side movement.

VALVE

FIGURE 62VALVE UNLOADER

Valve unloaders are-also available in a manual type whichincorporates a screw which moves the fingers in and out. Valveunloaders should be a last resort for controlling horsepower orcapacity because of the problems that have been experiencedwith present designs. In most cases valve unloaders have beeneliminated on equipment originally furnished with same, due tothe mentioned problems.

141

LUBRICATION SYSTEM

GENERAL

The compressor frame lubrication system is similar to theengine previously discussed. The system piping is shown inFigure 63 and incorporates a strainer, pump, pressure reliefvalve, cooler and filter. The lubrication system provides pressure lubrication at 30 to 40 psi to the main bearings, connecting rod bearings, and the piston pin bushings. Since the compressor frames are not subject to high temperatures and do nothave the combustion carbon problems like the engine's, oilchanges are minimum. Normally, customers change oil once a yearin compressor frames.

FILTER

~ili·~~=T~~--=-to ' "1

i

FIGURE 63

LUBRICATION SYSTEM

PUMP & RELIEF VALVE

The pump is a positive displacement type and is gear driven off the end of the crankshaft. Like the engine pump, it issubmerged in oil, so all parts are well lubricated and wear isminimum. On a major overhaul the bronze bushings around the oilpump shaft are normally replaced.

142

PUMP & RELIEF VALVE

The gaskets in the pump come in various colors and thecolor indicates the thickness. These gaskets are actually shimsand are used to set the end clearance of the pump. Care must betaken during reconditioning because the gasket thickness variesthe capacity of the pump.

The pressure control valve is a simple design and is nothing more than a spring loaded relief valve. To increase lubeoil pressure on the system, the lock nut is loosened and thescrew is turned clockwise, which increases the spring tensionand increases the oil pressure to the system. When the reliefvalve unseats, it bypasses excess oil back to the frame.

As recommended for the engine, a pre-lube type system isalso required for the compressor. The reason is that anytime acompressor is started without a pre-lube cycle, it will operatefor a short period of time without any lubrication to theinternal components.

Another maintenance tip that should be pointed out, isassociated with the pump and lubricator gear drive. Originallyall these gears were made of cast iron. Failures due to material in teeth design required a design change to steel gears. Itis recommended during compressor overhauls, that the pump and'ubricator gears be changed to the new design. It is not recom-

ended to only change one of these gears because of then having3 steel/cast iron running combination.

COOLER & FILTER

The lube oil cooler is a standard steel tube design. Waterflows though the tubes and the lubricating oil flows around thetubes. The important item to note here is that a temperatureindicator should be located on the cooler inlet and outlet. Thecompressor lube oil temperatures going into the frame should beIBO°F. In some cases, the oil must be heated so as to maintaina high enough temperature so that condensate will not form inthe frame. The compressor lube oil filter is of the same designas the standard engine filter. It will have an internal by-passvalve for cold start-ups. which normally causes no maintenanceproblems. The elements should be inspected periodically to seeif there is any babbitt or other foreign particles which maydepict a wearing part.

143

t

FORCE FEED LUBRICATION

METER PANEL o

PKG

O~1----"'-1 CYL

FEEDER MANIFOLD

PKG

CYL

MANIFOLD

LUBRICATOR

CHECK VALVE

PRESSURE INDICATOR

STRAINER

FIGURE 64

LUBRICATOR SYSTEM

SYSTEM

The force feed lubricating system provides oil to the various packing assemblies and the compressor cylinder, betweenthe piston and cylinder wall. The lubricator system is not whatis normally referred to as a closed system. All the oil thatpasses through this system is unrecoverable oil. It most commonly is removed by the gas stream of the compressor cylinderand therefore, becomes lost oil. The system design variesdepending on the compressor application and operating conditions.

Figure 64 shows the components of a basic system. Firstthere is a lubricator, that is driven off the auxiliary end ofthe compressor frame. The number of pumps varies depending onthe amount of oil needed throughout the system. In this particular example, two pumps feed into a common manifold. The manifold would normally have some type of high pressure indicatorthat would indicate if the system is overpressured. Includedwould be a small pressure indicator with rupture disc and a pinto indicate a high system pressure. Down stream of the manifoldthere should always be a filter or strainer to filter the

SYSTEM

lubricating oil. The system should also include a meter panelto indicate the amount of oil that the system is using.

Downstream of the meter panel is a no-flow valve and indicator. This valve signals a loss of oil or a no-flow conditionwithin the lubricator system. This alert or signal should shutdown the compression prior to damaging the unit due to lack oflubrication. The next item in the system is a feeder manifoldor distribution block. The block is sized to supply the variouslube points. This particular system shows three main lubricatordistribution blocks. One block feeding both packing glands andan individual block going to each cylinder. The size of theblock is dependent on the amount of oil required to that particular point.

The feeder manifold is sized to meter oil to specificpoints, in pre-determined quantities, so it is important toreassemble the manifold exactly as it was originally assembled.Mark each lube point connection to make sure that it is connected properly to the manifold. Pin indicators are also a partof the feeder manifold or distribution block. Indicators have arupture disc inside that is designed to burst under high pressure. When the rupture disc bursts, a pin pops out and indicates that the system is overpressured or has some other failIre within the system that needs to be corrected.

The amount of pressure on each lube point is dependenton the operating pressure inside that cylinder. The lubricationsystem pressure must exceed the compressor operating pressure,in order to deliver the required amount of lubrication to aspecific point. If the lube line is plugged or damaged, thesystem is protected by the rupture disc.

OIL VISCOSITY

The type of oil that is used in the force feed lubricationsystem is dependent on the type of compressor service.Pressures and the size of the compressor cylinder will affectviscosity selection. Figure 6S indicates various viscosityrequirements for Superior compressor cylinders. The only exception to this table is applications dealing with wet gas.Anytime there are liquids in the gas stream there is a tendencyto wash the lubricant from the cylinder wall and the only wayto maintain proper lubrication is to increase the viscosity ofthe lubricating oil. This problem would normally be indicatedby excessive piston ring wear or excessive cylinder wear orboth.

145

OIL VISCOSITY

MINIMUM VISCOSITY (SSU@210oF)o 10" 10"-15" 15" 20" ABOVf

PRESSURE(PSIG)

0-500

500 - 1000

1000 - 2000

2000 - 4000

4000 - UP

CYL,DIAMETERS

60-70

70-80

80-100

100-150

150-200

60-75

70-85

85-100

65-75

75-85

65-1

75- ~

, "

J:~:

FIGURE 65

OIL VISCOSITY

OIL QUANTITY

W64 900 RPM 900FT/MINLUBRICATOR RATIO 60:1 2 PUMPS

2X IX OIL OILCYL PKG BORE PKG CYL

1 4 6-1/2 8 122 4 5-1/2 8 123 4 6-1/2 8 lEi4 4 8-1/2 8 16

TOTALS = lEi + 27 = 43 INCHES

NORMAL OIL REQD = .2 PINT/DAY-IN X 43 IN = 8.6 PINT/DAY

BREAK-IN OIL REQD = 2 X NORM = 2 X 8.6 = 17.2 PINT/DAY

AT 900 RPM 7 60 OR 15 RPM CAPACITY/PUMP = 13.8 PINT/DAY

MAX CAPACITY FULL STROKE ON ALL 2 PUMPS = 27.6 PINT/DAY

NORMAL PUMP SETTING = 8.6 7 13.8 = ONE PUMP 63% STROKE

BREAK-IN PUMP SETTING = 17.2 7 27.6 = TWO PUMP 63% STROKE

FIGURE 65A

OIL QUANTITY

--------------

OIL OUANTITY

The amount of lubrication that is required for the lubrication system depends on the total area to be lubricated. Byadding the number of packings, the size of the rods, the sizeof the cylinder bores, and the area to be lubricated, the totalvolume of lubrication required at each point may be determined.Figure 65A gives a typical example and procedure for determining these requirements. A specific lubrication sizing sheet isa part of the data furnished with the equipment for a given application. There is a "break in" oil period, which is two timesnormal rate. After operating the unit for one or two weeks, thequantity may be cut to a normal lubrication quantity.

LUBRICATOR ASSEMBLY

Diacharge

Sight Cauge------~~t_ft

ooo

FIGURE 66

LUBRICATOR & DRIVE

I-

III

ooo

lII

147

~J<

LUBRICATOR ASSEMBLY

The lubricator assembly, or pump assembly, is availablefrom a number of suppliers and therefore there are varioustypes and models available. The one shown in Figure 66 is a boxtype lubricator assembly with individual pumps. Pumps can beadded or deleted depending on the amount of oil that isrequired. The lubricator has a right angle drive driven off theend of the crankshaft. The drive gear assembly contains bushings which would normally be replaced during overhaul. Thedrive coupling is normally a fiber disc type and it should bechecked for excessive wear or fatigue cracks. The lubricatorhas to be aligned with the drive coupling so there is end gap.Proper alignment can normally be accomplished by using a feelergauge or dial indicator.

To decrease the amount of oil pumped by an individualpump, loosen the lock nut on the plunger and screw in on theadjusting nut. By turning the nut clockwise, it restricts theplunger travel, which decreases the amount of oil output. Thesup~ly to these pumps is normally external and make-up tank, oran external supply source, must be available to the system.when the pump rocker arm is lifted by the rotating cam shaftwhich forces the piston in the upper stroke lubrication isforced into the system. The pump takes suction on the downwardstroke.

BALANCE

To assist in balancing Superior compressors there are ditferent weight crossheads and different weight balance nuts.Specifically, crossheads are available in weights of 50, 75,100 and 160 pounds. Ten different balance nuts are available in5-pound increments, from 5 pounds through 55 pounds.

Superior compressors are designed so that the reciprocating parts of opposing throws must be balanced within 1 to 2pounds. The reciprocating parts include the connecting rodassembly, crosshead pin assembly, piston-rod-piston nut-ringassembly and the balance nut. When a compressor is overhauledor revamped with different cylinders the weights of all reciprocating components must be recorded and balance nuts selectedso as to obtain the required mechanical balance.

It is only required to balance opposing throws. On a W64,for example, the total weights of throw number one are balancedagainst the total weights of throw number two. The same appliesto throws three and four. It is not necessary to balanceweights between throws number two and three because the crankshaft design is such that these two throws are not consideredto be opposing, for balancing purposes.

14

BALANCE

All the reciprocating parts vary in weight. Connectinge rods, with the same part number can vary in weight up to 2 -1 / 2pounds. Piston rods are either 2 or 2-1/4-inch in diameter andlengths vary depending on the guide, cylinder class and pistondesign. Pistons vary in weight due to material, diameter, ringrider grooves and different clearance requirements. Compressorswith consecutive serial numbers and pistons with identical partnumbers can vary in weight from 10 to 15 pounds. Obviously,rings also vary in weight depending on material, diameter,width and radial thickness. The point being, that any time anyof these components are changed, weights and balance must bere-checked.

Some of the parts are stamped with weights to assist themechanic in balancing. Crossheads have part numbers and areoften stamped with a weight. Balance nuts are identifiable bypart numbers. Compressor piston, piston nut, rod and rings arestamped on the outside edge of the head end with the assemblyweight and the piston weight is stamped on the same end nearthe nut area. Replacement pistons are stamped with the weightalso in the nut area and should be tagged with a balance warning note concerning the possibility of weight variations.

Figure 67 illustrates typical compressor balance data. As~n be seen, the parts for each cylinder is identified by part~mber and the actual measured weight of each part. A practical

:xample would be to first add the weights of the connectingrods and piston, ring and rod assemblies. For the 8-inch cylinder the weight of these two components is 232 pounds vs 289pounds for the 15-inch cylinder. There is a 57 pound unbalance.The first balance selection should be the crosshead. By choosing the lightest crosshead (50#) for the 15-inch cylinder,let's assume for the trial and error approach, that a 100#crosshead will work for the 8-inch cylinder. The actual weightsof the components are then 335 pounds for the 8-inch and 341pounds for the l5-inch or a six pound differential. By selecting a 5# balance nut for the l5-inch and a 10# for the 8-inchthe opposing throws are in balance within the specified tolerance of 0 to 2 pounds; 345 pounds vs 346 pounds.

The method of torquing balance nuts to the crosshead hasoften been in question. The torque that is normally called foron the nut is approximately 900 to 1,000 foot pounds. In thepast, because of the design of the compressor and the crossheadguides and the location of the various cylinders, it was verydifficult to install a torque wrench in the unit to obtain aspecified torque. In most cases this nut is torqued by using acrosshead balance nut wrench and a sledge hammer or a chainhoist. The most common problem in using this method is over'orquing, distortion of the threads, galling of the threads or

"erstressing the rod and/or nut.

149

P-920-175P-938-653

BALANCE

CYL. DIA. 8"GUIDE PT.NO.PISTON PT.NO.CONN. ROD TOTALPISTON, RINGS & RODCROSSHEAD P-901-076BAL.NUT P-900-962

TOTAL WEIGHT

CYL. DIA. 15"GUIDE PT.NO. P-920-175PISTON PT.NO. P-938-794CONN. ROD TOTALPISTON, RING & RODCROSSHEAD P-906-083BAL. NUT P-900-952

TOTAL WEIGHT

THROW HILENGTH 35"RING MATL-MOLY-DIWT. 96WT. 136WT. 103WT. 10

345

THROW H2LENGTH 35"RING MATL-BRONZEWT. 95WT. 194WT. 52WT. 5

346

~~

fiiI

FIGURE 67

COMPRESSOR BALANCE DATA

The procedure shown in the Figure 68 is a pre~calculated

method of obtaining a consistent torque. This method correlates nut rotation for different diameters with the requiredtorque of approximately 950 foot-pounds. For example, with a 5#hex nut on a 2-inch rod, the manner in which this nut would betorqued would be to first bring the nut up hand tight andinscribe the corresponding line on the nut and crosshead. Asindicated by the figure, then measure over on the nut counterclockwise a distance of 1/2-inch form the original line andinscribe a second mark. Then, tighten the nut with thecrosshead balance nut wrench until the second mark lines upwith the inscribed mark on the crosshead. The nut will then betorqued to approximately 950 foot-pounds. This value is basedon starting with clean, lubricated threads on both the rod andnut.

When excessive vibration on a compressor unit is reported,the first step is to determine if the unit is in mechanicalbalance. After removing all the valves from each cylinder thecompressor can be run in an unloaded condition. With the use ofa vibration analyzer horizontal and vertical amplitudes can bemeasured. Points of concern would be the crosshead guides andthe cylinders. The normal accepted vibration during mechanicaloperation is 0 to 8 mils. If vibration is excessive, then itmight be necessary to perform a tear down and a physicallyweigh all the reciprocating parts.

BALANCE

CROSSHEADINDEX LI NE

BALANCE NUTINDEX LI NE

CROSSHEAD NUT NUT CHORDALBALANCE NUT WEIGHT DIAMETER DISTANCE /lX/I ( IN. )PART NUMBER (LBS.) (I N. ) 2/1 RODS 2-:\;/I RODS

e P-900-952 (2") 5 4" HEX 1/2 5/8P-900-953 (2!t;")

P-900-962 (2") 10 6 5/8 3/4P-935-201 01,;")

BALANCE NUT TORQUE

FIGURE 68

If the vibration is found to be within the normal limits,then the next step would be to install the valves and load thecompressor to normal conditions. Rerun the vibration analyzertest and record the amplitude and frequency readings. If thevibration is found to be excessive, then it is probably causedby pulsation. The information should then be passed along tothe original packager who will run an analog study on the unit.Vibration caused by pulsation can usually be corrected by theaddition of orifices, chokes or re-designing the suction anddischarge bottles.

151

, .

f-,...,.

FOUNDATIONS

start with a geologist, since many problems have been experienced in the field because engines were installed over saltdomes, shale beds, or other structures which caused vibrationand/or alignment problems. Certainly, one should consult a goodfoundation specialist to assure that the location has propersoil bearing capabilities, that pilings are driven, ifrequired, and that the foundation is of adequate mass and properly reinforced with steel to support both the static anddynamic loads.

Drainage must be provided from the foundation. It is goodpractice to completely seal the foundation with one of the manyepoxy cement sealers now available. Oil and water impregnationhas probably resulted in more foundation damage than any othercause.

"J" hook bolts mounted directly in the concrete should notbe used, since they do not have enough holding power. Instead,one should go to a vertical foundation bolt design, grouted andin cans, which protect the bolt from concrete corrosion andpermit the utilization of bolt stretch.

Equipment installed on the foundation must be held down,supported and yet must be free to move horizontally for thermalexpansion.

---

~\" f- - ,

Ground;- \ ti- I

<

Level \ I~

\ I

I I

rFIGURE 70

FOUNDATION

1

BLOCK MOUNTING

GENERAL

For years, engines and related equipment were mounted onconcrete foundations, wherein sand and cement grout was pouredunder and around the engine and held down by foundation bolts.Later in time, new non-shrink grouts were developed, many ofwhich had metallic fillers from which they obtained their nonshrink characteristics. Many of these materials created problems because the fillers tended to expand due to chemical reaction with water and actually swelled and distorted the foundation support causing alignment problems. When engines aremounted in this manner, as the engine heats up it transmitsheat to the foundation on which it is sitting; therefore thefoundation swells from thermal expansion, as shown in Figure70. The ends of the engine and foundation radiate more heatthan the center, and this causes the entire mass to "hump" inthe middle and destroy alignment.

Relatively new epoxy grouts have also been tried on thistype of foundation but they do not solve the real problem. Tocure this humping problem, engine manufacturers went to railtype designs, wherein the engine sat on machined steel chocksand the chocks were positioned on rails. This type of mountingprovided relatively good ventilation under the unit and thesupport members served as heat dams, to reduce the heat transfer to the foundation. Rail type mounting was a considerableimprovement over solidly mounted units; however, despite theextended life afforded, many problems still continue to showup.

First of all, as the new epoxy grout came into being, theengine manufacturers tended to believe that epoxy bonded tosteel and keying was not necessary. This was a mistake. Railtype designs now have keys which tend to lock them into theepoxy grout.

Other problems also were encountered on these early raildesigns. Rails were of rectangular construction, with sharpcorners which tended to serve as stress risers and cause cracksin the epoxy material. Further, there was considerable failureat the bond line between the cement and the epoxy which, resulted in the foundation becoming saturated with oil and water.In addition, the epoxies were used in large quantities and notproperly contained. The extremely high coefficient of expansionof the epoxy, dictates that pour depths be kept to a minimumand long continuous pours be avoided.

Since there were many shortcomings with rail designs, thetendency now is toward sole plates, and this method offers manyadvantages. First, it is possible to set the sole plates in

155

GROUTING

FIGURE 72

EPOXY CHOCK

Whichever procedure is used, one thing must be kept inmind; the foundation design must be strong enough to supportthe skid and prevent movement. If the skid flexes, caused byfoundation deterioration, it will be impossible to controlalignment of the engine and driven members for any period oftime. Further, the skid itself must be strong and rigid andmust be gussetted. The skid must be also supported under thecross members with the chosen grouting approach.

Thermal growth between the skid and foundation presentsfar less of a problem than units which are block mounted, sincea great portion of the heat transferred from the engine is dissipated by the skid.

COLD ALIGNMENT

Since skidded units out number block units 10 to 1, thealignment discussion will be directed toward packaged units asshown in Figure 71. For those customers which have block mounted units, a very large portion of the following will alsoapply.

Prior to the unit being received In the field, the enginehas normally been test run at the factory or at the re-conditioning facility. In addition, the engine-compressor unit hasunder normal circumstances been test run at the packager and/orreconditioning facility. If these tests have not been performed, the customer should take that fact into considerationin the alignment and start-up of the unit in the field. For

15!

COLD ALIGNMENT

the purposes of this discussion it is assumed these tests havebeen made and that the compressor is permanently mounted bygrouting as reviewed above.

Ittested,that itcedure.correct

is important to note that even though the unit has been(it is mounted on a flexible skid) it does not meanis not necessary to go through the full alignment proThe skid is very flexible and alignment will not bein the "as received" condition.

The first objective is to rough align the unit in preparation for grouting the skid. Rough alignment includes levelingthe engine/compressor and taking a coupling alignment. By theuse of jack screws, raise the skid from I to 2 inches above thefoundation. Next, level the unit lengthwise and crosswise. Byusing a combination machinist levels and the skid jack screws,both engine and compressor can be leveled.

The next rough alignment check is made at the coupling.With the use of a mounting bracket and a dial indicator, asshown in Figure 73, the angular alignment of the coupling ischecked to determine the amount of twist and bending that hasbeen experienced during the transporting of the skid. The mainconcern at this point is the angular reading only.

The bracket that is used to measure coupling alignmentmust be of a design that has very little droop. The weight ofthe dial indicator and the clamping device will cause droopwhich will result in an erroneous alignment.

Bracket droop can be checked by the use of a 3-inch pieceof pipe with flanges and a handle, so the actual coupling canbe simulated. Next, mount the bracket and zero the gauges onthe top of the simulated stand. Then completely turn the standover so the gauges are hanging at the bottom and the dial indicator reading will be the droop of the bracket. Experienceindicates that the bracket with the least amount of droop is aflywheel flange bolt with a 3/4 to I-inch piece of thick walledsteel tubing welded to the head of the bolt.

By using the bracket as shown in Figure 73, the compressorhub side of the coupling is dial indicated with the shim packin place. The objective is to obtain an angular alignment within the specified coupling tolerances or as close to zero aspractical. The normal angular tolerance on a shim pack typecoupling is zero to .0003 per inch of indicator sweep diameter.For example, if the dial indicator is rotating on a 20-inchdiameter circle, then the maximum angular mis-alignment is.006. The angular reading can be corrected by using the jackscrews on the skid.

159

tCOLD ALIGNMENT

COMPRESSOR

FIGURE 73

COUPLING ALIGNMENT

- - -- -- ENGINE

,i

After completing the rough alignment, the next step wou)be to grout the skid to the foundation as outlined above. Onlthe grouting has set up, the skid foundation bolts can betorqued to secure the skid to the foundation.

FINAL

The next steps are required to complete the final coldalignment prior to start up. Included will be coupling angularand parallel alignment, engine pull down, setting the propertension on belts and chains, taking crankshaft deflections andfinally cylinder alignment/rod runout.

By using the bracket and two dial indicators as shown inFigure 73, angular and parallel misalignment can be detectedand corrected. Begin with the indicators at the top center position, the first step is to thrust both the compressor crankshaft and the engine crankshaft toward the coupling. Then zeroboth dial indicators, rotate the engine in a normal rotation toa 90° position and record both the angular and parallel readings. Repeat this procedure at 90° intervals, thrusting both

FINAL

crankshafts at this point. The crankshafts are thrusted becausefailure to do so will result in erroneous angular readings.

For illustration purposes assume that the following angular and parallel readings were recorded on an 8G825/W64 whilefacing the flywheel of the engine with an angular sweep diameter of 20-inches.

-.002

.000

-.003

ANGULAR

-.002 -.010

.000

+.030

PARALLEL

+.040

The maximum allowable angular misalignment is 20 x .0003 =.006; with the above readings we are only out by .003 in thevertical plane so the angular readings are well withintolerance.

The maximum allowable parallel misalignment is .004. Asthe various parallel readings are evaluated, the first indication is that at the side to side position, the engine and compressor are .025 off. Likewise the vertical reading is out ofalignment by .030.

The parallel readings indicate the need to rotate theengine to the 9:00 o'clock position. Next loosen all the enginehold down bolts and by using the jack screws move the engine tothe right (facing the flywheel) or toward the exhaust sideapproximately .025 inches. Both the front and rear ends of theengine must be slowly moved .025 inches because the angularreading is within an acceptable range. Now after making theside movement, retighten the engine hold down bolts.

Assume our next set of alignment readings were as follows:

161

FINAL

+.015

.000

+.030

+.015-.003

-.003

-.002

ANGULAR PARALLEL

These readings indicate that the angular alignment is stillwithin tolerance, the parallel side to side is within tolerance, but on the vertical a reading of +.010 indicates theengine is .015 inches too high. Therefore, the only additionalmovement that is required is to lower the engine .015 inches byremoving shims equally from front to rear.

An additional consideration, however, is the amount ofupward growth that will be experienced between the engine andthe compressor, when the engine warms up to normal operatingtemperature. On Superior units, the engine is normally set .OO~

to .003 lower than the compressor to compensate for the relative growth of the two units. Therefore, instead of lowerirthe engine .015 as first thought, it now should be lowered J18inches. Then an additional set of angular and parallel readingsare taken just to make sure everything is correct.

I

After completing the coupling alignment, the next checkthat should be made is to verify the coupling bolts are torquedproperly. After verifying that the thrusts are OK the engine isready to be torqued down.

With the engine sitting on shim packs at each hold downbolt, it must be made sure that each shim pack is tight andthat it is supporting the engine weight. As a final check during the process of torquing, it is recommended that a dialindicator on the bed be used at each foundation bolt. Intorquing the hold down bolts, if the dial indicator shows morethan .003 pull down, that particular hold down bolt must becompletely loosened and a .003 shim added. Be constantly awarethat the bedplate supports the crankshaft. Any distortion ofthe bedplate could be passed into the crankshaft and cause dis~

tortion of the crankshaft. On Superior units it is recommendedthat all of the hold down bolts on both sides of the bedplatebe used.

FINAL

The next alignment check would be to verify that there isno excessive distortion in the engine crankshaft. First checkthe radiator belts and water pump belts on the front of theshaft to make sure they are properly adjusted and will not distort the shaft in any manner. In addition, the timing chaintension should be checked as outlined under uCamshafts. u

The water pump drive belts and the radiator fan belt tension is a function of the centerline distance between the twosheaves and the sheave diameter. Figure 74 gives the recommended deflection force required to deflect a belt 1/64 of an inchfor each inch of span between the two sheaves. For example,assume a span of 24 inches and a small sheave diameter of eightinches. By applying a force of approximately nine pounds thebelt should deflect 24/64 or 3/8-inch. By applying from 8 to 11pounds force, if the deflection was less than or greater than3/8, the adjustable idler must be used to reset the belt tension. This is the same procedure that should be used on allbelt drives, in order to make sure that an excessive force isnot being applied to the crankshaft.

SITlall Sheave Speed Ratio ReCOITlITlended Deflection Force,lbs.DiaITleter Range Range Min. Max.

7.0 7. 1 107. 5 -- 8.0 2.0 7.9 118.5 - 10.0 to 9.3 13

10. 5 - 16.0 4.0 11 16

Span

Deflection1/6"''' per inch

span

FIGURE 74

BELT TENSION

163

,,-

FINAL

When starting the distortion check, keep in mind that tnormal limitations are not to exceed a total of .003 disto vnthroughout the crankshaft. It is recommended that special a~s

tortion gauge with graduations of 10 thousandths of an inch beused in checking web deflections on Superior engines.

Start the deflection with the throw adjacent to the flywheel. Install the distortion gauge in the center of the weband approximately one-inch in from the outside, as shown inFigure 75. After installing the gauge reverse the rotation ofthe flywheel, in an opposite' direction to normal, until thegauge is as close to the connecting rod as possible, but without touching the rod. Adjust the gauge so it has the capabilityof free rotation both in the plus and minus direction.Normally, a 100-thousandth spring pressure on the gauge issatisfactory.

Before the start of the deflection reading process, letthe ~emperature of the distortion gauge and the crankshaftequalize and then re-zero the gauge. As much as three to fiveminutes is required normally, but the required time is dependent upon the degree of temperature variance. Record the starting reading, then rotate the engine in its normal rotation downto the 90° position and record the third reading at top deadcenter. Continue to rotate to the next 90° position and recordthe fourth reading. Then rotate the engine until the dial inr'cator again gets as close to the connecting rod as possible 1

record the fifth reading.

75

CRANKSHAFT DISTORTION

_.. -------------

FINAL

We would continue to take distortion readings on each power cylinder as described above. An example of the normal reading at the throw adjacent to the flywheel would be as follows:

POSITION

I2345

DEFLECTION

.0000-.0005-.0017-.0005-.0000

The readings indicate the web is closed in the bottomposition, which is the normal reading because of the weight ofthe flywheel on the end of the shaft is pulling down on thecrankshaft indicating a minus reading, or closing of the web.It is not necessary to take the flywheel off the engine to takedistortion readings because experience indicates the normaldistortion in throw next to the flywheel on a Superior enginewill be between a -.0015 and a -.0018. When the engine is running the rotation of the flywheel will cause the flywheel torise and will bring the running reading close to zero.

As the readings are recorded toward the front of theengine the external forces such as the radiator belts, thewater pump drive belts and the camshaft drive chain will have atendency to lift the front of the crankshaft and the readingswill be in the positive at all recording points. Normal readingat the front of the engine would be a +.0005 to +.0008.

The concern when evaluating distortion readings would be ahigh plus reading on number one in comparison to the normalminimum reading on the throw adjacent to the flywheel. The maximum additive distortion cannot exceed .003. A +.002 on thefront throw and a -.0018 on the throw next to the flywheel, forexample, would be a total distortion of .0038 which exceeds themaximum.

It is important to again point out the objective of alignment, and that is to have the crankshaft run in the "asmachined" condition. The objective requires that the operationof the engine be taken into consideration when evaluatingcrankshaft distortion readings. Three classic examples ofcrankshaft distortion are as follows:

(A) (B) (C)

165

FINAL

Of the three examples MA H is the best crankshaft deflection shape because when the engine is running the force applto the shaft from the firing of power pistons will reduce thstatic distortion readings. HEH, in truth, is a hypotheticalexample because of the flywheel affect, but in comparison isnot as acceptable as MA H

, due to the fact that during operatthe static distortion readings will become worse. A deflectipattern similar to example He H is not acceptable. The continrotation of a crankshaft with distortion readings resultingthis static shape will result in a shaft excessively stresse

The next check that needs to be made is the alignment 0

the compressor cylinders. As shown in Figure 76, cold supporunder the guides, and bottle supports under the compressor cinders, help to decrease the amount of stress on the frame.

Prior to making the compressor rod run-out check, makesure that the bottle support is loose and is not applying anupward force on the cylinder. with the crosshead in its fullinward position, install a dial indicator in the vertical potion on the rod. Zero the indicator and rotate the unit untithe crosshead is in the full outward position. The indicatorreading is the rod run-out. The rod run-out should be check p

and recorded for each cylinder. The normal operating cha- would be for the piston rod to droop.

CROSS HEADGUIDE

COMPRESSORCYLINDER

HOT SUPPORT

FIGURE 76

COMPRESSOR CYLINDER ALIGNMENT

CLEARANCE

FINAL.010

.009

.008

I-:>

.007 0

z:>a:

.006 00a:

Z

.005 0l-V>

;;:.004 w

...J

"'..'".003 0...J...J..

• 002

.001

.000

12.5009.5005.750

DIA.CLEAR.

.038/.043

.020/.024

.015/.019

,6

.015 .020 .025 .030 .035 .0'<0 .045 .050

FIGURE 77

ROD RUN OUT

The amount of rod run-out that is allowed is dependent onthe cylinder diameter and the running clearance, as shown inFigure 77. An example would be a 12-1/2 inch cylinder with arunning clearance of .040. Allowable rod run-out for thatcylinder would be .008. If the run-out is found to be excessive, corrections can be made by the addition or removal ofshims between the cold support and the guide.

HOT ALIGNMENT

The engine and compressor is ready for the start sequenceand running up to temperature for hot alignment, when the proper alignment checks and corrections have been made. Afterobtaining full operating temperatures with the unit not loaded,the unit is shutdown and all the previous cold alignments arerepeated. Specifically the coupling, distortion and rod run-outchecks are each made and the readings recorded. After makingthe required changes and corrections, and it lS assured thatthe unit is aligned properly in the hot condition, the engine

.'" HOT ALIGNMENT

compressor package is ready for loading and the initial b ,K

in.

After the compressor discharge temperatures have reacheddesign levels, the discharge bottle supports, shown in Figure76, can be tightened to be just snug against the bottles. Excessive tightening of the support can destroy rod run-out.

As far as the suggested sequence of re-checRing the alignment, it varies with each installation, foundation, etc. On newinstallations it would be recommended that the alignment bechecked approximately 30 to 40 days after initial start-up. Ifthe alignment requires corrections, then the procedure shouldbe repeated within another 30 to 40 days. Once alignment isstabilized, the time span can be increased to 6 months. Theexperience at each interval will dictate if it's required todecrease or increase time period between checks. At a minimumit is recommended that a complete alignment check be made on arannual basis.

One thing that should be kept in mind, outside forces onthe piping of the compressor and/or engine can destroy alignment or create stress in cylinders, frames etc. These stressesare normally caused by misalignment and poor fabricating of th~

inlet and discharge piping. It is recommended that prior tostart-up of a new unit, the contractor be required to disnect the inlet and outlet flanges to the skid, to verify atthere is not any outside pipe force being applied directly tothe compressor unit.

PREVENTATIVE MAINTENANCE

PHILOSOPHY

There have been books on top of books written on the subject of maintenance of engines and compressors, all of whichoffer good suggestions, but none will solve maintenance problems without a continuous effort on the part of both theMaintenance and Operations Departments. Of course, even withconscientious people at the plant level, a good maintenanceprogram will die on the vine without proper company supportfrom the top.

All maintenance programs are influenced by company policies, which are many times outside the control of both themechanic and operator. Number one, if engineering does notproperly size or design the equipment to fit the application,then it will be next to impossible to maintain the engine andcompressor. Number two, if purchasing buys the equipment withonly cost in mind and does not consider quality, then the unitcould be a maintenance problem from the beginning. Number threeinvolves field operations. If it is the policy to have no downtime, then the people performing maintenance are going to patchand fix up items on a rush basis. In addition, if company policy does not properly define duties and classify jobs thenchances are good that the attitude of the people directlyinvolved in maintenance will be poor, resulting in a less thansatisfactory program.

The purpose of any maintenance program is to obtain maximum on line availability at a reasonable cost, on a dollar perbrake horsepower basis. The various types of programs are asfollows:

Catastrophic Type: Repair or overhaul after failure.

Progressive Type: Repair or overhaul one or two cylindersat a time.

Periodic Inspection: Inspect and replace as required.

Planned Overhaul: Based on equipment experience, overhauls are planned and scheduled well Inadvance of a major failure.

Maybe the reader can identify which of the above programsfits his company philosophies. Ideally the philosophy of goodpreventative maintenance program should be to:

16~

PHILOSOPHY

PERFORM

Inspections,Make Adjustments, TOService & Test

IDENTIFY

Minor Problems& MakeCorrections

TO

MAINTAIN

DesignEquipmentPerformance

The four keys to preventative maintenance are:

(1) Operation,(2) Inspection,(3) Troubleshooting, and(4) Overhaul.

All of the functions must be planned and executed with theone goal in mind, maximum availability at a reasonable cost.

OPERATION

As indicated above, close cooperation between the Maintp~

ance and Operations Department is the first key to good rna)tenance. Most problems can be detected by reviewing proper_maintained operating logs and detecting trends in pressure,temperature and speed parameters. The first item a mechanicshould ask for before inspecting or troubleshooting a unit fora suspected problem is the operating log. Well designed logsshould indicate alarm conditions for all readings.

Some suggested pressure devices that are recommended onthe engine for monitoring, alarm and/or shutdown ar.e: lube oil,jacket water, air manifold, and crankcase. Devices for monitoring temperature alarm and/or shutdown are lube oil, jacketwater and bearing temperature. Some additional recommended monitoring alarm and shutdown devices are overspeed vibration(both on the engine and radiator) lube oil level and expansiontank level.

Some recommended compressor pressure devices for monitorlng alarm and/or shutdown would be suction gas pressure, discharge gas pressure, lube oil pressure and lubricator no-flow.Compressor temperature monitoring alarm and/or shutdown devicesshould be suction and discharge gas on each cylinder and vibration_

•

INSPECTION

A typical inspection program for an engine and compressoris listed below. The customer is recommended to make up his owndetailed inspection program based on the particular operatingconditions of the installation. For those customers with limited personnel for a complete maintenance program, field serviceis available with competent mechanics, knowledgeable onSuperior engines and compressors. A well planned inspectionschedule is the second step in preventative maintenance.

Some suggested inspection type programs are as follows:

On a DAILY basis it is recommended that all logdata is recorded, check the load on the engine/compressor, check packing for leaks, check all theliquid levels, listen for excessive noise, andcheck lube oil consumption.

On a WEEKLY basis, the daily checks are made inaddition to making sure the linkage is free andcheck the lubricator.

On a MONTHLY or 1000 hour inspection, it is recommended that the valve clearances be adjusted, service the air and oil filters, as required, changesparkplugs, if required, and check the timing andchain/belt tension.

On a SIX MONTH or 4000 hours, it is recommended theair inlet side of the turbo be cleaned, run powercylinder compression test, check power valve sinkand alignment.

ANNUALLY or 9000 hour inspection should include rodand main bearing checks, inspection of bushings,compressor piston rings and compressor valveplates.

At TWO or THREE YEAR inspections or 18,000 to27,000 hours it is recommended the cylinder head bereconditioned. After three to four years of operation a complete overhaul is normally necessary.

Obviously the above recommendations or suggestions arebased on experience factors and are affected by many variablesand should be altered to meet the specific application. Thechecks and inspections listed are an attempt to set-up a disciplined program, instead of listing each item that requiresinspection at a given point in time .

171

TROUBLESHOOTING

The three most common errors in troubleshooting are:

(1) Not studying the operating log,(2) Failure to use available information as a mainte

nance tool, and(3) Making offsetting adjustments without fixing the

real problem.

It is amusing to see a troubleshooting operation startwithout at least referring to the basic operating data. In somecases, it may seem that this is an indication of lack of ability but the contrary is true. Troubleshooting operations oftenbegin with the arbitrary replacement of parts, or by adjustingbalance valves on all the power cylinders in order to improveload carrying availability. In both of these cases, many times,the real problem is not detected or fixed and, consequently,other parts of the engine can easily be overloaded to make upfor the deficiency of a single item. If time is of the essence,as ~~ always seems to be, the best way to maintain availabilityis to find the problem and fix it rather than skirting theissue.

OVERHAUL

In the same manner as described for inspection, overhaulsshould be thoroughly planned and a specialty company which willbe doing the work, consulted on a plan of action. The most common mistake in overhaul is one that results from an inspectionor troubleshooting excursion without pre-planning. Under theseconditions, the unit is torn down, parts inspected, and then anurgent call goes out for the required replacement parts. Ifscheduled properly by listing out carefully the items to bedisassembled, projecting the parts required and overhaul datasheets prepared in advance, costs can easily be cut by 25-30%.This cost savings will primarily result from proper utilizationof manpower and not having to push the panic button for therequired parts (air freight, etc.) A well planned overhaulwill consequently result in decreased down time.

A typical overhaul or inspection data sheet for main bearings is shown in Figure 78. Similar type recommended datasheets are available for rod bearings, pistons, connectingrods, heads, turbochargers, auxiliary equipment, setting alarmsand shutdowns, compressor valves, piston and rods etc. Thefirst step in setting up such data sheets is determining thecorrect procedure and then listing the data required to discipline the mechanics work.

OVERHAUL

CUSTOHER _ DATE, _

LCCATIOII _

MODEL'-- _ SERIAL NO. _

l\A.Ilf BLARI1lCS

fi~FCAP BASE

NO CAP BRG. ORIG. BASE BRG. ORIG. BRG. CAP cu:AIW'lCEA D B E C F TKICK AID BfE CfF THICK TORQUE BEFORE AFTER REIWlKS

1

2

)

4

5

6

FIGURE 78

MAIN BEARING DATA SHEET

MAINTENANCE COSTS

Figure 79 indicates the variable costs associated withpreventative maintenance programs. With no preventative maintenance the cost of repairs and lost production are prohibitive.With an excessive level of maintenance, the cost of repairs andlost production are minimum but the direct PM costs are prohibitive. Since product margins are dependent on the market level,the controllable factors are the cost of the PM program plusthe cost of repairs, Ideally, a preventative maintenance program should strike a medium between the two extremes, resultingin operating the engine and compressor at a competitive dollarsper brake horsepower which will allow a reasonable return onthe investment.

173

MAINTENANCE COSTS

xHIGH

MAINTENANCECOST

LOW~~••••Y

LOW , LEVEL OF MAU1TENANCE --------+-. HIGHNO PM EXCESSIVE PM

EXCESSIVE REPAIRS NO FAILURESAND FAILURES AND NO REPAIRS

• CONTROLLABLE MAINTENANCE COST = COST OF PM+

COST OF REPAIRS

FIGURE 79

MAINTENANCE COST

In summary, everyone involved has specific obligationstoward making sure the equipment performs at a reasonable cost.

VENDORS: Must furnish equipment and parts capableof specified service

OWNERS: Must maintain and operate the equipmentwithin designed specifications

MECHANICS & OPERATORS: Must be knowledgeable of allsystems, components and perform their dutiesin a conscientious manner

174

EnergyDynamics

PowerParts®

SUBJECT

PRODUCT BULLETINPB NO.lOl

To keep our Distributors and Customers informed of any changesor problems that may existing Superior Equipment, ProductBulletins and Technical Bulletins are pUblished and mailed on aperiodic basis. If a new part is being introduced or if adesign change has been made on a certain part, Product Bulletinsare printed to inform the end user. If a chronic problem existsin a Superior Engine or Compressor that has been resolved by orimproved upon by EnergyDynamics you are notified through printedTechnical Bulletins. Recommended repair and criticalinstallation procedures of certain parts are also defined in theTechnical Bulletins.

6-9-88

MARKETING DEPARTMENTENERGyDYNAMICS300 W. First, Alice, Texas 78332512/668-8311

EnergyDynamics

TECHNICAL BULLETINTB NO. 1018

PowerParts@

Proper Assembly procedures

SUBJECTREF: 4Y-1699 Governor Adapter & Drive Assembly For

In-Line 825 Series Engines.

Whenever assembling new or rebuilding the referenced assembly one(1) of a P-020-358 shim must be included in the parts list. Thisshim pack is required to properly set the end-play of the shaftand bearing assembly in the housing. The shim must be placedbetween the bearing spacer and the lower bearing. The correctassembly procedure is as follows:

1. Install the upper bearing onto the shaft (insure thatthe bearing is flush against the flange of the shaft).

2. Install the shaft & bearing into the housing.3. Slide the bearing spacer and the shim onto the shaft.4. Slide the lower bearing onto the shaft.5. Place the pinion gear onto the shaft and snug it up to

the shaft shoulder with the nut.6. Check the shaft and bearing assembly end-play (dial

indicator or other acceptable means). Record the amountof movement.

7. Remove the nut, gear, lower bearing & shim pack. Pealshims from the pack, equal to the amount of end-playthat was measured.

8. Re-install the shim pack, lower bearing, Woodruff key,gear, washer and nut. Torque the nut (per a standardtorque chart) .

This 'should result in the inner and outer races of the ballbearings being properly centered over the balls of the bearings.The remaining end-play will be limited to the clearance betweenthe balls and the races of the bearings themselves.

Failure to properly set the end-play of the assembly will resultin premature failure of the bearings and drive.

3-21-94

TECHNICAL SERVICE DEPT.ENERGyDYNAMICS300 W First, Alice, Texas 78332512/668-8311

EnergyOynamics

PowerParts®

SUBJECT

PRODUCT BULLETINPB NO.106

EnergyDynamics PowerParts® and Services

When the time comes to purchase replacement parts for yourSuperior and Ajax gas compression units, considerationsincluding the vendors quality, availability and price areinvestigated before making a final decision.

We totally support our customers research policies because wefeel that we should earn your respect and your business. Thefollowing points may be helpful in assisting you in making adecision when considering EnergyDynamics as your supplier.

A. PowerParts® Quality - Quality is the number one priority atEnergyDynamics. Comprehensive engineering studies areconducted in determining material selection and design. Thelatest technology utilized in the manufacturing process.Quality control and quality assurance programs are strictlyenforced to insure that all parts are dimensionally correctand meet manufacturing standards and specifications. If achange in design of a part is required extensive testing isconducted in-house and in the field, under actual fieldconditions, before it is made available to the market. Wecontrol the quality from initial manufacturing to thefinished product.

B. PowerParts® Availability - To support our customersoperation and our domestic and international stockingdistributor network, a multi-million dollar inventory levelis maintained by EnergyDynamics. Ninety-five percent of thenormal overhaul and repair items are shipped the same daythe order is received. Our computer-based system monitorsparts availability and production scheduling providingassurance that parts can be shipped world wide on a momentsnotice. You will seldom experience long lead times fromEnergyDynamics.


PB NO.106PAGE 2

C. PowerParts® Pricing - EnergyDynamics pricing is based solelyon the actual cost of manufacturing. You will neverexperience an across the board price increase that othercompanies use simply to cover overhead. Our pricing is themost competitive in our industry and is designed to offeryou a quality part at the best available price. Any priceincrease is announced well in advance and quotations areheld firm for a specified period of time.

D. PowerParts® Warranty - EnergyDynamics stands behind thequality of all PowerParts® as indicated in our clearlystated warranty policy, printed on all shipping documentsand invoices. Should a part become defective during thewarranty period and the problem is determined to be with thepart, our policy is to immediately repair or replace thepart to reduced any additional unscheduled downtime. Wetotally support everything we sell.

E. EnergyDynamics Technical Support - In addition to qualityPowerParts® the other thing that has set us apart from ourcompetitors is our reputation for technical service. Whenyou buy a PowerPart® you can count on the most knowledgeabletechnical support available anywhere today. To remain aleader in this area, we are constantly working to improveour technical service. As good as we are, we realize we canbecome even better.

F. EnergyDynamics Customer Training - EnergyDynamics providesprofessional training for customer personnel in themaintenance and operation of Superior and Ajax equipment.The training programs are conducted by experienced hands-oninstructors and can be held in our facilities or yours. Acomplete color slide presentation is utilized reflectingcross-sections of engines, compressors, sub-components andaccessories. Maintenance and operation manuals are providedfor all personnel.

QUALITY POWERPARTS~ AND TECHNICAL SUPPORTA WINNING COMBINATION

6-12-90

EnergyDynamics

PowerParts®

SUBJECT


Clean Burn Conversion KitsFor Superior Turbocharged EnginesRevision 1

EnergyDynamics continues to be the leading developerof updating kits for your Superior Engines.

The latest development is a Clean Burn ConversionKit which surpasses EPA requirements through outthe rated speed and BHP range of your turbochargedengines.

Contact EnergyDynamics or their closest distributorfor details and quotations prior to your nextoverhaul.


PB NO.I07PAGE 2

8GTLX CONVERSION KITSALES DATA SHEET

Company Name: __

Mailing Address: __

Engine Model: __

Operating Speed Range: _

Plant Location: _

Mailing Address: __

Serial Number: __

RPM To RPM

Engine Rating: __ BHP@ RPM Plant Elevation: __

Heating Value

Ambient Temperature Extremes: of to-----------------

Fuel Gas Temperature: oF

OF-----------------

BTU/SCF

Governor Manufacturer: --------------------------Serial Number: ------------

Mode1 : _

Designation: _

Turbo Manufacturer: ----------------------Part Number: _

Starting System (I): Internal

Mode 1 : __

Designation: _

External

Type and Model of Starter: __

Control System (I): Pnuematic

Manual Start

Air/Fuel Control Preference (I) Pnuematic

Electric

Auto Start

Electric

Ignition System Manufacturer: _

Type (I): Shielded

Model

Non-Shielded

Timing Control Preference (I) Manual Auto

Cylinder Head PIN: Camshaft PIN: -------------------Intercooler PIN: Jacket Water Pump PIN:

---------------

Oil Cooler Included with (I): Intercooler Water System

Jacket Water System

Air Manifold Temperature Controller YesType & Model

No

Additional Information:--------------------

7-25-90

EnergyDynamics

PowerParts®

SUBJECT

TECHNICAL BULLETINTB NO.l009

Development of Superior GT825Clean Burn Conversion Kits

GENERAL - In response to continued customerrequest EnergyDynamics made the commitment to bethe first to develop Clean Burn Conversion Kitsfor existing Superior turbocharged engines. Theinitial development incorporated a fully instrumented 8GTL engine with a H35 Elliottturbocharger, standard Altronic ignition, pneumatic air/fuel controls and loaded on a water brakedynamometer at varying BHP and RPM.

OBJECTIVE - Develop simplified best availabletechnology emission control conversion kits withminimum changes to Superior turbocharged enginesfor GTLA/B reduced maintenance, increased availability and comparable certified emissions.

RESULTS - As indicated by the attached, thedevelopment objective was exceeded.

TECHNICAL SERVICE DEPT.ENERGvDVNAMICS300 W. First, Alice, Texas 78332512/668-8311

•

TB.NO. 1009PAGE 2

8GTLX EXHAUST EMISSIONS

PERCENT IGNITION EMISSIONSRPM BHP RATED TIMING (GRAMS/BHP-HR)

LOAD ( 'BTDC)NOx CO

900 1100 100 20 2.0 3.0

900 825 75 20 1.5 3.5

900 550 50 20 1.5 4.0

750 917 100 12 2.0 3.0

750 688 75 12 2.0 3.5

750 459 50 12 1.0 3.0

600 733 100 6 3.0 3.5

600 550 75 6 2.0 3.5

600 367 50 6 1.0 3.0

NOTES:

1. FUEL GAS - 90% Methane and low heating value of 900 BTU/SCF with aconsumption of 7,100 BTU/BHP-HR at 900 RPM and 1,100 BHP.

2. TEMPERATURE - 100'F ambient, 130'F air manifold and 120'Fintercooler water.

3. HEAT REJECTION - at 900 RPM and 1,100 BHP: 7,500 BTU/MINintercooler, 37,000 BTU/MIN* jacket water and 4,500 BTU/MIN lubeoil.

* Engine equipped with standard water cooled exhaust manifold.

8-1-90

•

•

TB NO. 1009PAGE- 3

6GTLX EXHAUST EMISSIONS

PERCENT IGNITION EMISSIONSRPM BHP RATED TIMING (GRAMS/BHP-HR)

LOAD ( . BTDC)NOx CO

900 825 100 20 2.0 3.5

900 619 75 20 1.8 3.9

900 413 50 20 1.7 4.0

750 688 100 12 2.0 3.0

750 516 75 12 1.8 3.3

750 344 50 12 1.0 3.5

600 550 100 6 4.0 3.4

600 413 75 6 2.0 3.6

600 275 50 6 1.0 4.0

NOTES:

1. FUEL GAS - 90% Methane and low heating value of 900 BTU/SCF with aconsumption of 7,150 BTU/BHP-HR at 900 RPM and 825 BHP.

2. TEMPERATURE - 100'F ambient, 130'F air manifold and 120'Fintercooler water.

3. HEAT REJECTION - at 900 RPM and 825 BHP: 4350 BTU/MIN intercooler,26,000 BTU/MIN* jacket water and 4,000 BTU/MIN lube oil.

* Engine equipped with standard water cooled exhaust manifold.

9-9-94

EnergyOynamics

PowerParts®

SUBJECTPROBLEM

PRODUCT BULLETINPB NO.I02

Camshaft Lobe WearSuperior 510 & 825 (Inline-Vee) Series Engines

Premature Camshaft Lobe Wear Caused byInadequate Pin to Roller Lubrication

I. Backqround: For years now the OEM, specialty repair companies,and users have been fighting camshaft lobe wear problems on bothSuperior Inline and Vee engines. In the past five years thisproblem has become so prevalent that, with no solution, severalcompanies have developed split lobes for the convenience ofquick lobe replacement. Most OEM user supported repaircompanies are now refusing to recondition Superior camshafts.

EnergyDynamics has been working on the solution to the problemfor over three years and our 1987 extensive 825 enginelobe/roller assembly test uncovered the cause of lobe wear (seeattached Product Bulletin No.102) - inadequate lubricationbetween the roller and pin resulting in galling, causing theroller to hang-up and skid across the lobe.

•

II . Tests: Laboratory test of an Inline 825 consisted ofinstallation of eight (8) design and material variations withthe objective to: (A) find out why we had premature camshaftlobe wear, (B) find out if we had adequate lubrication betweenthe roller and lobe and between the roller and pin and, (C)which design/material combination solves the problem. Theprocedure included prelube with standard engine hand primingpump, maximum initial run time of six (6) hours, disassemblyinspection replacement of scuffed parts and reassembly. After

. promising design variations proved satisfactory in standardsplash lube environment each improved design was tested withextended one (1) week continuous runs with a guard to reducesplash lubrication to zero (lobe, roller and pin were lubricatedwith only oil running down push rods from head) and repeatingthe above disassembly, inspection, replacement and assemblyprocedure. Clear plastic side cover doors were used to visuallyobserve time required for adequate prelube as well as runningsplash lubrication.


•

•

PB NO.102

II. Tests: Cont'd .

Laboratory test results were as follows:

1. The required pressure for adequate prelube, using 40weight oil @ 85°F, and the standard hand priming point is 5to 7 PSIG and a minimum of 1-1/2 to 2 minutes of pumping isrequired to reach this pressure plus 3 minutes continuouspumping is required to adequately prelube of the lobe andguide assembly.

2. Lubrited guides, rollers and lobes reduce start-upgalling and scuffing.

3. Splash lubrication adequately lubricats the roller tolobe contact surface. No mat~rial or design problems werenoted with the standard PowerParts® lobe.

4. The new PowerPart® design prelubes the roller-pin areaby filling the pin top groove and through hole to the loadside of the pin.

5. All standard available designs showed roller to pingalling after as low as 1-1/2 hours of operation in splashenvironment. No roller to pin galling was present in thenew PowerParts® design in one (1) week continuous run withzero splash lubrication.

Field Test Results Were As Follows:

The new PowerParts® design was next field tested on an Inline825 engine. Procedure included hand pump prelube, maximumcontinuous initial run time of 70 days and repeating the abovedisassembly, inspection and reassembly procedure. We arepleased to report that field tests indicated no pin galling andno roller/lobe galling or wear.

III. Solution: The solution to the above problems a new'PowerPart® cam follower assembly with the state of the artmaterials and a design which increases the roller to pinlubrication over 10 times. The attached cross sections,compares the OEM and PowerPart® assemblies and indicates thedesign changes which result in proper pin to roller lubrication.

7-6-88

•

•

PB NO.I02PAGE 3

C/-I/\/ FOLLOWER ASSEMBLY-FOP. ,\!C'CEL SID SU~ERIDR ENGINES-

•

F-YG-6fB-O-X.FCVvERPflRTS @

ITEMNO

12.34

5

ENOYNPART NO.

F·C·cC0~-E

P-c-20-<4';:'-1~-x -2O.2cc- E-XF-C2342F-':-23E5-/

YG-0fiB-OOE/VI.

OEM.FrJAT fIK).

C-L{]'x-BC-20J4-A-lCC-20':G-BC-2342C-2:3E5

•

YD .::~V. iV""

PAGE 4

CAM FOLLOWER ASSEfVIELY- FOR MODEL 825 SUPERIOR ENGINES -

P-02G-B89-XPOWERPlJRTS@

',1-\-026-859OEM.

ITEM ENOYN OEMNO. PART NJ. PART tKl.

t P-C2G-Eff-X P-COI-O?I2 P-G/9-528-X-/ A-O/9-528J P-OI4-842-x £-014-E424 P·1I5-2C5 A-1J5-:305

EnergyDynamics

•PowerParts®

SUBJECTPROBLEM:

TECHNICAL BULLETINTB NO.1002

Camshaft Lobe WearSuperior 510 & 825 (Inline-Vee) Series Engines

Premature Camshaft Lobe Wear Caused byInadequate Pin to Roller Lubrication

Camshaft lobe wear problems have existed for several years withalmost everyone pointing the guilty finger toward lobe hardness,depth of lobe hardening or lobe-shaft assembly procedures. As aresult of extensive testing (see attached Technical BulletinNo.I002) we are pleased to introduce two new PowerParts®Assemblies which are designed to properly lubricate the roller topin area plus incorporating state to the art materials.

I. SOLUTION:

The attached drawing sections with the following outlinesthe solution to the above problem and the advantages of thenew PowerParts® cam follower assemblies over other availablestandard designs.

•

ITEM DESCRIPTION

1 Roller

2 Pin

3 Guide

ADVANTAGE

New material through hardened, widestpossible roller contact surface andlubrited.

New material through hardened, groovedand drilled for proper lubrication toroller contact surface.

Three holes for pin to rollerlubrication, knife top edge forincreased side lubrication and nospecial requirements on installationorientation.

TECHNICAL SERVICE DEPT.ENERGyDYNAMICS300 W First, Alice, Texas 78332512/668-8311

•TB NO.l002PAGE 2

II. INTERCHANGEABILITY:

Dimensionally all the components of the new PowerParts®assemblies are interchangeable with the OEM assemblies.Based on the fact that EnergyDynamics has an improveddesign, we, however, do not recommend using any of thecomponents of the PowerParts® assemblies in the OEMassemblies, nor using any OEM parts in our assemblies. Fordesired results worn guides, rollers and/or pins should bereplaced with the new PowerParts® complete assembly.

7-6-88

TB NO.l002PAGE 3

CAM FOLLOWER ASSEMBLY-FOR IY"CCEL 510 SUr:ERIOR ENGINES-

F-YG-6E8-0-XF('(/l/ERPfJRTS @

I7[MNO

1234

5

ENOV,NPART',C.

F-O"e:Cl'J' £:P-o-20:L;-j..-l~CKJ-2J::k-E-X

F-O- 2:5.:";2F-D-23E5-x

YG-fJDS-OOEM.

OENI.FiJRT I\Q.

C-2033-8C-L:034-A-1CC-203G-PC-e:342C-2385

CAM FOLLOWER ASSEMBLY- FOR MODEL 825 SUPEP,IOR ENGINES -

PAGE 4

P-02G-889-XPOWERFfJRTS@

)1-\-026-859OEM.

ITEM ENDm OEMNO. PART tV. PART W,

i P-02G-Ett-X B-aJI-0712 P-oJ9-528-kl A-O/9-52B.3 P-OI4-E"'2-X £-014-6424 P-IIS-XJ':: A-IIS-205

EnergyOynamcs

PRODUCT BULLETINPowerParts@

PB NO.109

SUBJECT Pilot Fuel Check ValveSuperior Clean Burn EnginePart Number P-031-665-Y-1

P-031-665-VIn1ine EngineVee Engine

PURPOSE: To advise our customers of our NEW IMPROVED DESIGN pilotfuel check valve for Superior Clean Burn Engines.

The attached drawing reflects another improved designPowerPart®. EnergyDynamics new pilot fuel double check valvehas been installed in Superior Clean Burn Engines in excessof (12) months resulting in no downtime for removal andcleaning.

The male thread size is 7/8" X 14 and is interchangeablewith your existing 7/8" check valve. The only requiredchange is a slightly longer piece of tubing to the inletconnection.

In older engines utilizing the smaller 3/4" X 16 checkvalve, it will be necessary to rework your existing cylinderheads to accept the larger 7/8" check valve.

Since the 1/4" tubing lines from the gas header to the checkvalve are custom made for each individual engine we recommendthat new tubing lines be installed due to a possiblevariation in the length of the line.

We also suggest that the combustion chambers be blown outafter removal of the old check valve and prior to theinstallation of the new valve. This will remove any excesscarbon stuck in the check valve passage way.

Our check valve is a stock item and can be shipped uponreceipt of order. To place your order or if you have anyquestions contact EnergyDynamics or your EnergyDynamicsdistributor.

7-19-93MARKETING DEPARTMENT

ENERGyDYNAMICS300 W. First, Alice, Texas 78332512/668-8311

e e eOATtl:ISYM R~VJSION RECORD AUTH.IOR.I CK.

~ /

II'(?'

"'~-(1)~

~I.;~

-"-':

,~

FOR "VEE" ENGINES lISE CJmCK VAJ,Vl\A::;::;lIMl3LY ttl'-O::ll-ooS- V

FOR "VEE" ENGINE APPLICATIONS, THEP-031-RR5-S-5 FITTING IS NOT Im(~{JlnED.

BILL OF MATERIAL

ITEM QTY PIN

TOLERANCES(Il)l(CIl,.T AS NOTIrOI

DESCRIP ENERGYOYNAMICS j INC.SCAL..£

C/-IECK VALVE ASSY: - PILOT FUEL

OEtlMAL DRAWN BY 1j I

J. Terrell :p I

NONE APPROVEO BY J..5 g; ,+ I I tv

i:RACT,ONAL.. ITITLE

CHECK VALVE I±

CHECK VALVE

BALL

FITTING

1'-0:31-665-S

P- 031-·665-S-1

P-031-665-S-5

P-031-665-3-4

1

1

1

1

1

2

3

4ANGULAR

+

DATE IDRAWING NUMBER

8-27-93 I P-O~/ -665-1" -J

EnergyDynamics

PowerParts®

SUBJECT


8GTL Conversion Kits forWhite Superior 8GT-825 Engines

Are you exeriencing problems with your older 8GT-825 engines suchas detonation, piston and liner scuffing, premature wear, andunbalanced due to the control system? If so, we suggest you joinour list of satisfied customers by installing an 8GTL ConversionKit during your next scheduled overhaul to reduce fuelconsumption, maintenance costs and downtime.

Major improvements include:

1. Lower Compression Six Ring Pistons

The new 8 3/4:1 compression ratio reduces peak firingpressures by 20%. This reduces dynamic stresses on thecylinder block, crankshaft, bearings and other internalcomponents.

In additional, the kit provides more stable operation andenhances engine tolerance for variations in fuel composition.

2. Fuel Supply System

The new larger diameter fuel header reduces pulsations andprecision orifice plates at each cylinder head improvescombustion stability and maintains balance of loading betweencylinders.

The fuel metering valve is controlled by the governor tomaintain speed regardless of load.


PB NO.103PAGE 2

3. Camshaft

The cam profile has been revised and material specificationsimproved to reduce wear. The timing has been changed tomaximize time for fuel mixing to reduce fuel consumption by 6%.

Air flows are greater and the lower average peak firingcompression pressure results in lower sensitivity todetonation.

4. Air/Fuel Control System

The new simplified system improves control of the air/fuelratio throughout various speed and load ranges. Pneumatic orelectrical controller positions a single air butterfly valve tomaintain air manifold pressure in relationship to gas headerpressure at all times.

Items included in the conversion kit are:

1. Pistons2. Piston Rings3. Piston Pin Snap Rings4. Cylinder Head Gasket Kits5. Camshaft Assembly or Re10be

Existing Camshaft6. Gas manifold Assembly

& mounting Elbows7. Gas Orifice Plates8. Gas Metering Valve & Control

Shaft Gas Inlet Piping9. Air Butterfly Housing

with Fixed Deflectors10. Single Air Butterfly and

Air Actuating CylinderInstalled by EnergyDynamics

11. Turbocharger Nozzle Ring12. Air/Fuel Control Pane1

Pneumatic or Electronic13. Starting System with Start

and Run Regulators(If Required)

14. All Necessary Fittings,Hardware & Gaskets forMounting

15. Assembly Drawing, InitialStart-up Adjustments andInstructions and OperatingData

•

Prior ·to your next overhaul, contact EnergyDynamics or your localEnergyDynamics distributor for a quotation on the complete kit andassistance in calculating your return on investment.

8-9-88

Energy[)ynamiCS

PowerParts®

SUBJECT

PROBLEM:

PRODUCT BULLETINPB NO.l04

Intake Jet Ram Manifold andImpco Carburetor ConversionSuperior 6GB25-BGB25 Engine

1. Inability to locate replacement parts for theold style Ensign carburetors and regulators

2. Engine hard to start3. Engine backfire at start-up and under loaded

conditions4. Need additional engine horsepower

If you have experienced any of the above listed problems you maywant to consider updating your old style GB2S Superior engine withthe installation of an Intake Jet Ram Manifold and ImpcoCarburetor Conversion kit. The new style one piece intakemanifold and single Impco 600 D carburetor provides more reliablestarting capabilities and eliminate engine backfiring which couldcause internal damage to your engine. If your engine is equippedwith (10:1) compression ratio pistons you could also realize a 20%increase in engine horsepower depending on the BTU of your fuelgas.

The kit includes an intake manifold air induction manifold, airbutterflies, Impco 600 D carburetor, linkage control shaft withmounting brackets and all of the required hardware and gaskets.An illustration of the major components is attached. The governoris not included in the kit but can be furnished as an additionalitem.

The kit part numbers are listed below.a quotation on the complete kit contactlocal EnergyDynamics Distributor.

For additional details andEnergyDynamics or your

Kit Part Number

P-027-l9lP-027-l92P-027-l93P-027-l94

Description

Kit for 6GB25 engine with mechanical governorKit for 6GB25 with Woodward governorKit for 8G825 with mechanical governorKit for 8G825 with Woodward governor


•

PB NO.I04PAGE 2

With the installation of the new Ram Manifold Kit you will alsoneed either the engine mounted air cleaner kit or the remotemounted air cleaner. The following is a list of the dry type oroil bath air cleaner kits.

Kit Part Number Description

P-027-l95 Engine mounted oil bath air cleaners for the6G825 engine.

P-027-196 Engine mounted dry type air cleaners for the6G825 engine.

P-027-197 Engine mounted oil bath air cleaners for the8G825 engine.

P-027-198 Engine mounted dry type air cleaners for the8G825 engine.

P-006-029 Remote mounted oil bath air cleaner for the6G825 and 8G825 engine.

9-20-88

TTO GOVERNOR

AIR

AIR INDUCTIONMAN I FOLD __--'\)

INTAKE MANIFOLD

l'CONTRDL SHAFT

IMPCO 600CARBURETOR

PB NO.l04PAGE :J

AIR INLET ADAPTERFOR ENGINE MOUNTEDOR REMOTE AI R CLEAI

•

EnergyOynamcs

PowerParts®

SUBJECTPROBLEM:

TECHNICAL BULLETINTB NO.1003

Cylinder Liner Installation ProceduresSuperior Engines

Inadequate Liner to Block Seal825 Series Engines - 10" Bore, 10-1/2" Stroke

If you are a Superior engine user you most probably have experiencedjacket water leakage past the liner either in the top or bottom borein the cylinder block or have had a piston seize in a new liner atstart-up. The following are procedures and recommendations to followwhen installing cylinder liners:

A. After removal of the liners it is imperative that the top andbottom bores in the cylinder block be clean and smooth to obtain agood seal in both areas. Additionally, any pitting will prohibitthe gasket on the top of the liner and the o'ring on the bottom ofthe liner from sealing properly. If severe pitting due tocavitation-corrosion is present consideration should be given tosleeving the bores. (See attached for correct dimensions.) Thecomplete lock does not have to be replaced in most cases.

1. The top counter-bore of the cylinder block should bethoroughly cleaned and the liner flange seating area lapped toobtain a flat sealing surface. A lapping tool can be made bycutting off the top of an old cylinder liner and turning itover where the liner flange will fit in the top bore of theblock. A fine grit lapping compound can be used. Be sure toclean this area after lapping and remove all grit and metal.

2. The bottom bore should also be thoroughly cleaned and all rustand residue removed. The o'ring seating area an be smoothedover by using emery cloth or a fine grade sand paper.

•

B. Thoroughly clean the new liners and measure the I.D. beforeinstallation to ensure that the liner is round and has not beendamaged or distorted in shipment or storage. Special attentionshould be given to the under side of the liner flange and o'ringgrooves to make sure that they are clean of all debris. Theo'ring grooves should also be checked for excessive buildup of anyspecial coating the has been applied, such as lubrite.

TECHNICAL SERVICE DEPT.ENERGyDYNAMICS300 W. First, Alice, Texas 78332512/668-8311

TB NO.I003PAGE 2

C. Install the top gasket and o'rings. Lubricate the o'ringsafter they are installed on the liner. Never lubricate both sideof the o'rings as they will tend to roll during installation. Ttbottom bore in the cylinder block can also be lightly lubricated.Do not use a heavy grease for lubrication.

D. With the use of the liner insertion tools slowly lower theliner through the top bore and press into position. Make surethat the liner to block gasket is not cocked and is seated in theblock counter bore before pressing the liner all the way in. Thiwill eliminate the possibility of the gasket catching the top edcof the block and rolling.

E. After the liner is installed it is recommended that the I.D.be checked and honed to ensure that an o'ring did not roll durin~

installation possibly distorting the lower liner inside diameter.You can measure the liner with inside micrometers, set your honeat engine bore and pass the hone through the liner in the pistontravel area. If the liner is out of round it will be immediateI)detected. This type of check will eliminate any possibility ofthe piston seizing in the liner after start-up or when the load j

applied to the engine.

F. Remember that cylinder head torque is the only thing thatholds the liner in the cylinder block and prevents excessive linemovement. If the head is loose the liner movement will beexcessive. The cylinder head should be torque in an alternatingsequence and be brought down as evenly as possible. It isimperative to keep the cylinder heads torqued to the proper valuEat all times.

G. To reduce liner movement and reduce the amount of water pressureon the head to liner gasket, some users have elected to go withoversize liners. The oversize portion of the liner is theshoulder just below the gasket or liner seating area. The lineris either built up or a .020" oversize new liner can be furnishe(by EnergyDynamics and machined to fit in the block bore.Clearance between the liner and block at this point is recommend!to be .001" to .002".

TB NO.1003PAGE 3

CYLINDER BLOCK - 825 SERIES ENGINESTANDARD DIMENSIONAL DATA

TOP OF BLOCK

{ ~_-,"[3.L--_c

~o

OLD STYLE BLOCK

A. Counter Bore Depth -.388"-.390"B. Counter Bore Diameter-11.625"C. Lower Top Bore Diameter-11.250"D. Bottom Bore Diameter-11.125"

NEW STYLE BLOCK

A. Counter Bore Depth-.432"-.434"B. Counter Bore Diameter-11.625"C. Lower Top Bore Diameter-11.250"D. Bottom Bore Diameter-11.125"

NOTE:

3-13-89

1. The top bore seating surface is to be perpendicular with thebottom bore diameter within .001" T.I.R.

2. The flatness of the liner seating area in the block shouldnot exceed a variation of more than .002" T.I.R. around thefull circumference of the seat. The finish on the seat areashould be a minimum of 63 RMS.

EnergyOynamics

TECHNICAL BULLETINPowerParts®

TB NO.lOO?

SUBJECT

Gentlemen,

Maintenance Programsfor Superior Engines

The basic intent of any maintenance program is for unitprotection to prevent major failures, insure on-lineavailability and to maintain cost of operating at a reasonablelevel per brake horsepower per year.

Each application must be reviewed and considerations wouldinclude: (1) annual operating hours, (2) load and generaloperating conditions, (3) importance of on-line availability,(4) manpower and (5) budgets.

The attached programs are typical for Superior gas enginesoperating under normal conditions. Please refer to each programas a reminder of important items which should be included inyour existing programs. The actual intervals of service mayvary dependent on your application.

If you need additional copies, have any questions or desireadditional information, please contact EnergyDynamics or theirlocal distributor.

5-10-90


MAINTENANCE PROGRAM - 51090-1(TYPICAL FOR SUPERIOR NATURALLY ASPIRATED GAS ENGINES)

f NTRODUCTIONThis maintenance schedule is for Superior G-825 Series Engines operating under normalconditions. It may be necessary to change some of the intervals of service due toabnormal conditions associated with load, fuel gas analysis, ambient temperatures, etc.

MAINTENANCE CHART

p~p::H::>0-~p::

(J)

(J) (J) (J) (J) (J) p::<: p:: p:: p:: p:: ::>

::> ::> ::> ::> 0-- 0 0 0 0 ::r:::r: ::r: ::r: ::r:

I T E M S E R V I C E >< 0..:l 0 0 0 0 0H 0 0 0 0 0

i <: 0 0 0 0 ~p ...... N ~ co N

!Operating Log Data XI TemperaturesI,

i Operating Pressures Log Data X

Load & RPM Log Data X

Air Cleaner Elements Check Differential X

..'ater Level Check X

Lube Oil Level Check X

I Lube Oil Consumption Check XI~

i Crankcase Vacuum Check XI

I Governor Oil Level Check X

I Starter Lubricator Fill XI

Check XI Oil Filter DifferentialI

: Leaks Check X

Control Lindage Lubricate X:

Fan Shaft Bearings Lubricate XI

l Valve Clearances Adjust (Hot) X

Oil Filter Elements Replace X

i Lube Oil Analyze X

r Spark Plugs Replace X,

Ignition Check~ Timing XI

I Drive Chains Adjust XI

~ears & Sprockets Inspect X

_Jrive Belt Adjust X

Air Filters Clean/Replace X

1 C2rburetor Adj us t\

XI~ - - - L_

Page 2Maintenance Program - 51090-1(Typical for Superior Naturally Aspirated Gas Engines)

p

g;jH:::>CYI£lP<:

C/)C/) C/) C/) C/) C/) P<:< P<: P<: P<: P<: :::>

:::> :::> :::> :::> 0--. 0 0 0 0 ;:I::;:I:: ;:I:: ;:I:: ;:I::

:>< 0I T E M S E R V ICE .-1 0 0 0 0 0

H 0 0 0 0 0< 0 0 o· 0 ~p -' N ~ co N

System Vents Check X

Lube Oil Change X

Crankcase Clean X

Lube Oil Strainer Clean X

Governor Oil Change X

Crankcase Breather Clean X

Safety Shutdowns Test/Adjust X

Starter Alignment Check X

Cam Lobes & Followers Inspect X

Coupling Alignment Check X

Crankshaft Distortion Check~

X

Magneto Replace X

Magneto Drive Coupling Replace X

Cylinder Compression Check X

Camshaft Timing CheckX

Main Bearings Spot Check XRod Bearings Spot Check X

Cam Bearings Spot Check X

Rocker Arm Bushings Spot Check X

Cylinder Head Torque Check X

Rod Bolt Torque Check X

Main Cap Torque Check X

Flywheel Torque Check X

Coupling Torque Check X

Foundation Bolt Torque Check X

Drive Belts Replace X

Thermostat Elements Test X

Backfire Relief Valve Inspect X

Lube Oil Relief Valve Inspect X

Secondary Ignition Wires Replace X

Gaskets & Seals Replace X

Page 3Maintenance Program - 51090-1(Typical for Superior Naturally Aspirated Gas Engines)

1'=1~~HDCY~~

'"'" '" '" '" (/) ~...: ~ ~ ~ ~ D

D D D D 0-.. 0 0 0 0 :x:::x:: :x:: :x:: :x::

I T E M S:>-< 0

E R V ICE ....:l 0 0 0 0 0H 0 0 0 0 0...: 0 0 0 0 ~

1'=1 ..... N ~ co N

Cylinder Heads Rebuild X

Exhaust Manifold Inspect & Test X

Thermostat Elements Renlace X

Piston Rines Renlace X

Pistons Inspect X

Cylinder Liners Inspect & Hone X

Cylinder Block Inspect i X

Rod Bushings Replace X

Connectine Rods Inspect X

Rod Bearings Replace X

Main Bearings Replace X

Crankshaft Insnect X

Cam Bearings Replace X

Drive Bushings Replace X

Roller Bearings Replace X

Oil Pump Drive Springs Replace X

Hubs, Gears & Sprockets Insnect X

Lube Oil Pump Rebuild X

Water Pump & Idler Rebuild X

Drive Chains Replace X

Carburetor Rebuild X

Linkage Rod Ends Replace X

Linkage Bushings Replace X

Throttle Assemblies Rebuild X

Governor Rebuild X

Primary Ignition Wiring Replace X

Fan Shaft Bearings Inspect I X

Lube Oil Cooler Clean & TestI,

X

Ignition Coils Clean & Test 1 X

Camshaft Idlers Rebuild X

Page 4Maintenance Program - 51090-3(Typical for Superior Clean Burn Engines)

t=l~p::H::>et~p::

CJ)CJ) CJ) CJ) CJ) CJ) p::...: p:: p:: p:: p:: ::>

::> ::> ::> ::> 0

--- 0 0 0 0 ::c::c ::c ::c ::cI T E M S E R V ICE

~ 0H 0 0 0 0 0H 0 0 0 0 0...: 0 0 0 0 --rt=l ...... N --r ro N

Primary lenition Wirine Reolace X

Fan Shaft Bearines Insoect X

Lube Oil Cooler Clean & Test X

, Ignition Coils Clean & Test XI


c)-lO-90

•

MAINTENANCe PKOGRAM - 51090-2

(Typical for Superior Turbocharged Gas Engines)

INTRODUCTION

This maintenance schedule is for Superior GT-825 Series Engines operatingunder normal conditions. It may be necessary to change some of the intervalsof service due to abnormal conditions associated with load, fuel gas analysis,ambient temperatures, etc.

MAINTENANCE CHART

0

~H::>0-~p::

UlUl Ul Ul Ul Ul p::..: p:: p:: p:: p:: ::>

::> ::> ::> ::> 0--.. 0 0 0 0 ::r:I T E M S E R V ICE

::r: ::r: ::r: ::r::>< 0H 0 0 0 0 0H 0 0 0 0 0..: 0 0 0 0 ""0 .-< N "" CX) N

Cylinder Balance Check & Adjust X

Operating Temperatures Log Data X

Operating Pressures Log Data X


Air Cleaner Element Check Differential X

Water Level Check X


Lube Oil Consumption Check X

Crankcase Vacuum Check X

Governor Oil Level Check X

Starter Lubricator Fill X

Oil Filter Differential Check X

Leaks Check X

Control Leakage Lubricate X

Fan Shaft Bearings Lubricate XValve Clearance Adjust (Hot) X


Lube Oil Analyze X

Spark Plugs Replace XIgnition Timing Check XDrive Chains Adjust X

Gears & Sprockets Inspect XDrive Belts Adjust X

J:'age "-Maintenance Program - 51090-2(Typical for Superior Turbocharged Gas Engines)

.

p~p::H;:J0'~p::

enen U) en U) en p::<>: p:: p:: p:: p:: ;:J

;:J ;:J ;:J ;:J 0--. 0 0 0 0 ::r:::r: ::r: ::r: ::r:

I T E M S E R V ICE :>< 0...:I 0 0 0 0 0H 0 0 0 0 0< 0 0 0 0 -:T

I p ..... N -.:T co N


Fuel Mixture & Balance Adiust X


Lube Oil Change X

Crankcase Clean X

Lube Oil Strainer Clean X





Cam Lobes & Followers Inspect XI


Crankshaft Distortion Check X

Magneto Replace X



Camshaft Timing Check X

Turbo-Impellar Clean & Inspect X

Main Bearings Spot Check X

Rod Bearings Spot Check X

Cam Bearings Spot CheckX

i Rocker Arm Bushings Spot Check X

I Cylinder Head Torque Check X

I Rod Bolt Torque Check X

i Main Cap Torque Check XI,I


I Coupling Torque Check X


Drive Belts Replace i XI


Page 3Maintenance Program(Typical for Superior

51090-2Turbochar$ed Gas Engines)

.

~~p::H::::>0'~p::

CIlCIl CIl CIl CIl CIl p::< p:: p:: p:: p:: ::::>

::::> ::::> ::::> ::::> 0

----0 0 0 0 :0:::0:: :0:: :0:: :0::

>< 0

I T E M S E R V ICE H 0 0 0 0 0H 0 0 0 0 0< 0 0 0 0 "'"I 0 ..... N "'" co N

Turbo-Turbine End Clean & Inspect X

.Lube Oil Relief Valve Insoect X

I Secondary Ignition Wires Reo lace X X

Gasket Seals Replace X

:Rebuild XTurbocharge


, Exhaust Manifold Inspect & Test X

IReplace Xi Thermostat Element

! Piston Ring Replace X

Pistons Inspect X

Cylinder Liners Inspec: t & Hone X

Cylinder Block Inspect X


Connecting Rods Inspect X,

i Rod Bearings Replace X


I Crankshaft Inspect XI

Cam Bearings Replace X

Drive Bushings Replace X

I Roller Bearings Replace XII Oil Pump Drive Springs Replace X

Hubs, Gears & Sprockets Inspect X

Lube Oil Pump Rebuild I X


Drive Chains Replace I XI

i Gas Valves Rebuild IX

I,

I Linkage Rod Ends Replace i X

Linkage Bushings Replace i XI

Governor Rebuild i I X

Primary Ignition Wiring Replace I t X

Page 4Maintenance Program - 51090-2(Typical for Superior Turbocharged Gas Engines)

p

'"0::H;:J0-~

0::(J)

(J) (J) (J) (J) (J) 0::~ 0:: 0:: 0:: 0:: ;:J

;:J ;:J ;:J :=> 0

---- 0 0 0 0 :r::r: ::c :r: ::cI T E M S E R V ICE >< 0

....:l 0 0 0 0 0H 0 0 0 0 0<: 0 0 0 0 -<tP ...... N -<t co N

Fan Shaft Bearings Inspect X

Lube Oil Cooler Clean & Test X

Ignition Coils Clean & Test X


MAINTENANCE PROGRAM - 51090-3

(Typical for Superior Clean Burn Engines)

INTRODUCTI ONThis maintenance schedule is for Superior GTLA & GTLB Series Enginesoperating under normal conditions. It may be necessary to change someof the intervals of service due to abnormal conditions associated withload, diesel and fuel gas analysis, ambient temperatures, etc.

MAINTENANCE CHART

p~~H::>0'~~

Cf.)Cf.) Cf.) Cf.) Cf.) Cf.) ~..: ~ ~ ~ ~ ::>

::> ::> ::> ::> 0

--- 0 0 0 0 ~~ ~ ~ ~

>< 0H 0 0 0 0 0

I T E M S E R V I C E H 0 0 0 0 0..: 0 0 0 0 -<j"p ...... N -<j" <Xl N

-- -~--------Cylinder Balance Check X

Operating Temperatures Log Data X-

Operating Pressures Log Data X


Air Cleaner Elements Check Differential X. - ..- - . . . , ., .' _. -Water Level Check X


Lube Oil Consumption Check X .•.

Crankcase Vacuum Check X~-_.- - .. _._------------- --- _.- .._-----

Governor Oil Level Check X

Starter Lubricator Fill XI Oil Filter Differential Check X

Leaks Check X

Control Linkage Lubricate Xi Fan Shaft Bearing Lubricate X

i Valve Clearances Adjust (Hot) X


Lube Oil Analyze X

Spark Plugs Replacei :

X I !Ignition Timing Check X i ,

Drive Chains Adjusti

I X- - . ~

I

Gears & Sprockets Inspect X I

Drive Belts Adjust X I



.

p~.x:H~

I·0'~.x:

~(/)

(/) (/) (/) (/) .x:<t: .x: .x: .x: ~

~ ~ ~ ~ 0-- 0 0 0 0 ::r:::r: ::r: ::r: ::r:

I T E M S E R V ICE >< 0.:l 0 0 0 0 0H 0 0 0 0 0<t: 0 0 0 0 -orp ,...; N -or a:> N

Fuel Mixture & Balance Adjust X


Fuel Cell Check Valves Clean & Test X

Exhaust Wastegate Inspect X

Lube Oil Change X

Crankcase Clean X

Lube Oil Strainer . Clean X





Cam Lobes & Follower Inspect X


Crankshaft Distortion Check X

Magneto Replace X



Camshaft Timing. Check X

Turbo-Impellar Clean & Inspect X

Fuel Cell Spot Check X

Main Bearings Spot Check X

Rod Bearings Spot Check X

Cam Bearings Spot Check X

Rocker Arm Bushings Spot Check X

Cylinder Head Torque Check X

Rod Bolt Torque Check X

Main Cap Torque Check X


Coupling Torque Check X


Drive Belts Replace X


.

p~~H;::>CY~~

CJ)CJ) CJ) CJ) CJ) CJ) ~

< ~ ~ ~ ~ ;::>;::> ;::> ;::> ;::> 0-- 0 0 0 0 ;I1;I1 ;I1 ;I1 ;I1

I T E M S E R V I C E >< 0,....1 0 0 0 0 0H 0 0 0 0 0< 0 0 0 0 -<tP .--< N -<t 00 N


Turbo Turbine End Clean & Inspect X

Lube Oil Relief Valve Insoect X

Secondary Ignition Wires Replace X!I

Cylinder Heads Inspect With Scope XiI,

Gaskets & Seals Replace X

Turbocharger Rebuild X


Exhaust Manifold Inspect & Test X

Thermostat Elements Replace I X

I Piston Rings Replace X,

I Pistons Inspect X

I Cylinder Liners Inspect &Hone X

Cylinder Block Inspect X


Connection Rods Inspect X

I Rod Bearings Replace X


! Crankshaft Inspect X

i Cam Bearings Replace ! X

! Drive Bushings Replace X

Roller Bearings Replace X

Oil Pump Drive Springs Replace X

Hubs, Gears & Sprockets Inspect X

Lube Oil Pump Rebuild X


Drive Chains Replace X

! Gas Valves Rebuild X

Linkage Rod Ends Replace X

Hinkage Bushings Replace X

Governor Rebuild X

EnergyOynamics

PowerParts®

SUBJECT

TECHNICAL BULLETINTB NO.l008

Procedure For AssemblyAjax Injection ValveP-YAE-S098-T-3

I. VALVE ASSEMBLY

A. The valve seat and guide are held in place by aninterference fit. They should be frozen by placing ina freezer, dry ice, or liquid nitrogen. The intent isto reduce the size of the part which reduces theamount of pressure reuqired for installation.

The seat (P-BM-1014l-A) should be installed in thehousing (P-A-2562-2) so that the seat bottoms-out inthe counter bore.

The guide (P-K-789l-A) should be installed so itprotrudes into the gas passage. The proper positioncan be confirmed by measuring from the outer mostsurface of the housing (seat-end) to the end of theguide. The guide is properly located when thedimension is 1 5/8 inches.

A hole must be drilled in the guide after installationto emit lubrication. A 1/8" drill it is required.Insert the drill in the lubrication passage of thehousing and drill through the guide wall.

B. The installed guide bore should be .437-.438 inches.In the event reaming is required, a .437 inch straightreamer should be used.

C. Standard automotive type valve seat grinding equipmentcan be used to finish grind the seat.

A pilot mandrel is inserted into the guide bore, toinsure the seat surface will be centered to the guidebore.


- - ---------------------

TB NO.IOOSPAGE 2

I. VALVE ASSEMBLY - CONT'D.

A power driven stone and holder is then piloted ontothe mandrel and grinding can begin.

The stone should touch the seat lightly at first toverify the seat is located in the housing boreproperly. If the stone contacts the seat in one smallarea, check to insure the seat is set squarely in thecounter bore and not cocked.

Grinding should continue until the stone makes fullcontact 360 0 around the seat.

D. Once grinding is completed the valve (P-BM-IOI40-A)should be lapped to the seat with fine lappingcompound.

E. Wash all parts before final assembly.

F. Lubricate the valve, seat, and guide bore with a goodgrade motor oil. Install the valve into the guide.Install spring (P-BM-IOS69-A) and retainer(P-BM-IOI45). Using a valve spring compressor,compress the valve spring and retainer far enough toexpose the two grooves cut into the upper valve stemand install two locks (P-BM-IOI43).

G. Install the grease fitting (P-BM-I0046) and prelubethe valve stem with two to three pumps ofhigh-temperature grease (P-BM-1173S).

II. VALVE ACTUATOR

A. Install seal (P-BM-11736-A) into bore of plungerbarrel. The flat side of the seal must be toward theinjection valve.

Lubricate the plungerfrom the flanged-end.end of the plunger andvalve when installed.

and insert itA short bossmust be away

into the barrelis machined on onefrom the injection

B. Install the o-ring (P-BM-1634S-A-215) and lubricatewith a good grade of motor oil. Install the plungerand barrel assembly (P-YAE-S097-H-3) through thebarrel retainer plate (P-A-4371-2), from the a-ringside. The barrel flange will seat against the a-ring.

TB NO.100SPAGE 3

II. VALVE ACTUATOR - CONT'D.

C. Install o-ring (P-BM-1634S-A-212) and spring(P-A-272S-A) into cap (P-A-2565-F-3) and assemble thecap to the barrel and retainer assembly, securing themwith three socket head cap screws (P-03CS0406PC).

D. Install two roll pins (P-BM-10245-B) into housing(P-A-256l-1). Install o-ring (P-BM-1634S-214) intothe groove in the barrel bore of housing (P-A-2561-1).

E. With the valve housing sitting in an upright position,place six springs (P-BM-11654) in the shallow counterbores of the housing.

F. Carefully install the cap and barrel assembly into thevalve housing.

Lubricate the adjusting collar (P-A-4370) threads with"Never-Seez" or a good grade anti-seize and installcollar over the cap assembly.

III. FINAL ASSEMBLY AND PRE-ADJUSTMENT

A. Install gasket (P-A-2569) between the valve assemblyand the actuator.

The assembly is held together with four (P-01CSOS32PC)cap screws and 1/2" nuts installed through four boltholes. These bolts should be tight enough to hold theassembly snug, but do not over tighten. At valveinstallation time, remove and discard 1/2" nuts.

B. The final bench adjustment can now be made.

Turn the adjusting collar clockwise (looking from thecap-end), until it bottoms out. !!CAUTION!! Do notforce the collar. Then turn the collar counterclockwise one and one half turns.

Install two socket head set screws (P-01SS0403PC) intothe threaded holes in the collar and tighten untilsnug. Do not over tighten. These screws are designedto prevent the collar from turning once set.

6-1-90

FLE.L IN

Ji1

P-YAE-5098-T-3BILL OF MATERIALS

TB NO.1008PAGE 4

ITEM123456789

101112131415161718192021222324

OTY1111I111II12I2161111142J

PINP-A-2561-1P-A-2562-2P-A-2565-F-3P-A-2569P-A-2728-AP-A-4370P-A-4371-2P-BM-I0046P-BM-I0140-AP-BM-I0141-AP-K-7891-AP-BM-1014JP-BM-I0145P-IlM-I0245-BP-BM-I0869-AP-IlM-11654P-BM-11736-AP-BM-16348-A--212P-BM-16348-214P-BM-16348-A-21SP-YAE-S097-H-Jp-OICS0832PCP-01SS0403PCP-OJCS0406PC

DESCRIPTIONHOUSINGHOUSINGCAPGASKETSPRINGCOLLARRETAINERFITTINGVALVESEATGUIDEKEEPERSRETAINERROLL P~NS

SPRINGSPRINGSSEALO-RING0- RINGO-RINGPSTN ASSYCAPSCREWSSETSCREWSCld)SCREWS

EnergyDynamics

PowerParts®

SUBJECT

PROBLEM:

TECHNICAL BULLETINTB NO.100l

Cavitation - CorrosionSuperior (Inline-Vee) Engine Block825 Series Engines

Deterioration of the cylinder block in the upperand lower liner bores. Premature liner pitting anddeterioration. Coolant leakage into the enginecrankcase or bedplate which could cause extensivedamage and costly repairs.

The cavitation - corrosion problem has existed for several yearsbecause of the cylinder block design and water-water treatmentprocedures. The two primary causes of cavitation - corrosion are:

1. Mechanical movement (vibration) of the cylinder linerat very high frequencies commonly referred to as thebell ringing effect. The movement of the liner isusually perpendicular to the axis of the crankshaft.In all water systems there is a certain amount of airentrained within the system and the mechanicalvibration of the liner causes air bubbles to form andcollapse on the liner and block surfaces. As thebubbles collapse shock forces are imparted to thesesurfaces causing pitting and erosion. This isreferred to as cavitation.

2. When a chemical change in a metal or anelectrochemical reaction occurs the metal exposed tothe coolant is changed into various compounds such asiron oxide which attacks the surfaces. Where and towhat degree it will progress depends on the quality ofthe water, type of corrosion inhibitor, the metalsthat are exposed, surface temperature, vibration andstress. As little as 1/16" of iron oxide bUildup canaffect the heat transfer and coolant flow. Thischemical reaction is referred to as corrosion.


TB NO.lOOlPAGE 2

RECOMMENDATION: Water and Water Treatment

It is recommended that the water be de-ionized rather than rawwater which contains high concentrations of chlorides, sulfates,dissolved solids and visible suspended solids such as silt. Ifraw water is used as a diluent or added to the system as make upwater it would not have a hardness in excess of 170 ppm. Thecoolant and additive package must provide adequate cooling to theengine, protect against freezing, give adequate boiling protectionand provide corrosion protection. The coolant is normally anethylene or propylene glycol based antifreeze. The propyleneglycol based antifreeze provides superior cavitation - corrosiveprotection. The commercial automotive type ethylene glycolantifreeze does not provide adequate corrosion protection forindustrial heavy duty continuously operated engines. The freezingpoint of pure ethylene glycol based antifreeze is OQF and when itis diluted with water it provides freezing protection below O~.

As the percent by volume of ethylene glycol is diluted from 100%to 60% the freezing point drops from OQF to -60 QF. As the percentis diluted further the freezing point raises to +32 Q F inapproximately a straight line relationship. The recommendedcoolant concentration for engines is not less than 33% ethyleneglycol and not more than 60%. The boiling point is also affectedby coolant concentration. The greater the coolant concentrationthe higher the boiling point. A good quality of water, the propercoolant concentration and the proper additive package will assistin reducing the severity of cavitation - corrosion problems.Coolant analysis programs are also very important and should beconducted on a regularly scheduled basis.

CYLINDER BLOCK REPAIR:

In a lot of cases cylinder blocks can be repaired in the upper andlower liner bores rather than purchasing a new block. The repairconsists of machining the upper or lower bores and installing aninsert to bring the bore back to standard dimensions.

Lower bore insert - PIN P-G825-203Upper bore insert - PIN P-G825-204

If one or two bores need repaired this can be accomplished in thefield however if the damage is extensive and several or all of thebores are in need of repair it is more economical to send theblock to a qualified machine shop.

TB NO.lOOlPAGE 3

IN ADDITION, listed below are preventive measures usedsuccessfully by various Superior engine users to alleviate theseverity of cavitation - corrosion.

1. Raise the elevation of the expansion tank 1'-2' toprovide more head pressure to the suction side of theengine water pump. In all instances the expansion tankshould be vented to the atmosphere.

2. Maintain at all times the recommended cylinder headtorque which reduces liner movement.

3. Coating on the 0.0. of the cylinder liner with chrome orpolymer coating. A nitrided liner shows no significantimprovement.

4. Pressurize the water system from 2 - 5 PSI by installinga cap on the expansion tank.

5. Use of oversize liners in the upper liner area just belowthe liner flange which reduces liner movement and waterpressure on the liner to block gasket reducing waterleaks in this area.

6. Vent the water pump suction housing to the bottom of theexpansion tank. This vents entrained air at the pumpsuction. This in in addition to venting the thermostathousing and the highest point in the cooler to the bottomof the expansion tank.

We recommend that you contact a reliable water treatment companyand review the details of the engine water system to be treated,metals in the system, operating temperature and pressures, historyof the cavitation and corrosion problems, the type of engine andthe engine operation.

6-9-88

EnergyOynamics

PowerParts®

SUBJECT

TECHNICAL BULLETINTB NO. 1010 - REV. 1

Water Cooled Exhaust Manifoldson Superior Engines

HISTORY: Water cooled exhaust manifolds on Superior as wellas other types of engines develop leaks. Some canbe attributed to the quality of the welding,internal design, but most can be created by externalstress or improper installation.

INSPECTION & INSTALLATION SUGGESTIONS

1. Use a machinist straight edge or string line to check forbending or warpage of the flanges on both the exhaust andintake manifolds. If required, the flanges can be milledinline to relieve stress or prevent leaks.

2. Fill the water section of the exhaust manifold with hotwater and hydrostatically test with air at 50 PSIG. Checkfor leaks.

3. With the cylinder heads installed, nuts hand tight,install the intake manifold and tighten the flangesslightly (approximately 15-20 ft. lbs.). Use machiniststraight edge or string line to verify the cylinder headexhaust flanges are inline.

4. Install the exhaust manifold and tighten the flanges thesame as the intake manifold (approximately 15-20 ft.lbs.).

NOTE: "V" series engines are equipped with exhaust elbows.Special adjustments and alignments are required asfollows:

A. With the intake manifolds installed as instructed in3 above, install an elbow on each cylinder head.

B. Use a machinist straight edge or string line toadjust and tighten all elbows (both right and leftbanks) slightly (approximately 15-20 ft. Ibs.).Install and tighten the exhaust manifold to theelbows.


----------

Page 2

5. With the manifolds or a combination of manifolds andelbows installed as instructed Torque all cylinder headsusing the proper sequence to the specified torque.

6. Tighten manifolds and elbows (flV" engines) to thecylinder heads. Normal torque for 1/2" - 13 capscrews is46-48 ft. Ibs ..

7. Exercise care and make the necessary checks to eliminatestress on the exhaust manifold during the installation ofthe water piping, expansion joint, exhaust piping, andturbocharger if applicable. The water piping should beequipped with Aeroquip type couplings, properly located.Expansion joints should be installed with the properstretch to eliminate stress at normal operatingtemperatures. Turbochargers require proper shiming andadjustments to avoid stress, and exhaust piping supportsshould not be connected to the ex~aust manifold.

For assistance and additional information, please contact ourService department or our Distributor within your immediate area.

11-17-94

------------

EnergyDynamics

PowerParts®

SUBJECT

TECHNICAL BULLETINTB NO .1011

VALVE CONVERSION - OLD STYLE "VEE" ENGINE45° TO 30°

•

OLD PAR'l' NUMBER REPLACEMENT PART DESCRIPTION

P-002-389 (45 0) P-023-971 (30°) EXHAUST VALVE

P-008-324 (45 0) P-023-969 (30°) INTAKE VALVE

P-002-391 (45 0) P-022-492 (30°) EXHAUST SEAT

P-012-224 (45 0) P-022-948 <30°) INTAKE SEAT

P-013-161 P-022-949 EXHAUST VALVE GUIDE

P-002-915 P-022-491 INTAKE VALVE GUIDE

P-4A-1581 P-022-490 SPRING RETAINER

P-022-489 SPRING SPACER

P-021-127 GAS VALVE SEAT

5-26-92


EnergyDynamics

TECHNICAL BULLETINPowerParts®

TB NO.I012

SUBJECT Oil leaks between the cylinder heads andcylinder block on Superior 6-G-SI0 engines.

PROBLEM: Existing engines are equipped with a rubbergrommet seal arrangement between the cylinderhead and block. Due to insufficient crush,hardening of the grommet due to hightemperatures, etc. leaks develop.

SOLUTION: The attached lists components drawing(P-SK-SlOO) outlines the procedure andcomponents list required for converting to anexternal oil supply system. This wouldeliminate the grommets.

For further details, components, and/orassistance, please contact EnergyDynamics ortheir distributor in your immediate area.

9-29-92


e e eP-SK -5700

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DR CK

5 6 P-061-012

DATE REV REVISION RECORDnn NOT USE GALVANIZEO nTTiNGS TAP [X/STING HOl[ 7/8"NPT ANO PLUG USING IT[M

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'!\JCHES

FRACTIONAL PowerParls e

± 1/64" TITLE CONVERSION FROM INTERNALROCKER ARM OILER- TO EXTERNAL OIL SUPPLY LINES

DATE SCALEAPPLICATION 6G5 10 SUPERIOR 7/15/93 NONE

JDRAWING NUMB~ REVDRAWN BY JS ,.- A r""\,..-'"\ ~,-. , /