Maintenance of Diesel Engine(Version2)

1 Abstract

The training was in Suez Canal authority – dredging department, which

contains a workshops to make maintenance for it and other tugs, boats and

ferry.

At motor workshop we have seen total overhauling to Volvo diesel motor and

total assembly and disassembly of it also during the overhauling the engineer

explained the machine parts and its function, mechanism of motors and

problems and its remedy.

At the machinery workshop where the motor parts and boats and dredger

parts are made, and we have some information about the production

machines and how to work on them.

2 Table of Contents1 Abstract.........................................................................................................................................1

2 Table of Contents..........................................................................................................................2

2.1 List of figures :........................................................................................................................3

3 Main text.......................................................................................................................................4

3.1 Introducton............................................................................................................................4

3.2 Historical background............................................................................................................6

3.2.1 Suez Canal Construction History....................................................................................6

3.2.2 Suez Canal Use and Control...........................................................................................7

3.2.3 The Suez Canal Today....................................................................................................8

3.2.4 Significance of the Suez Canal........................................................................................8

3.3 Main component of Diesel engine:........................................................................................9

3.3.1 Cylinder Head:-..............................................................................................................9

3.3.2 Cylinder Head Gasket:-.................................................................................................10

3.3.3 Valves:-........................................................................................................................11

3.3.4 Piston:-.........................................................................................................................11

3.3.5 Piston Ring:-.................................................................................................................12

3.3.6 Connecting Rod:-..........................................................................................................13

3.3.7 Crank Shaft:-................................................................................................................14

3.3.8 Camshaft:-....................................................................................................................15

3.3.9 Cooling system:-...........................................................................................................15

3.3.10 Fuel injection:-.............................................................................................................16

3.3.11 Turbo Charger:-............................................................................................................17

3.3.12 Lubrication System:-....................................................................................................18

3.4 4 stroke................................................................................................................................19

3.4.1 The Intake Stroke:........................................................................................................19

3.4.2 The Compression Stroke:.............................................................................................19

3.4.3 The Power Stroke:........................................................................................................20

3.4.4 The Exhaust Stroke:.....................................................................................................20

3.5 2 stroke:...............................................................................................................................21

4 References...................................................................................................................................22

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2.1 List of figures :

Figure 1 ( cylinder head)........................................................................................................................9Figure 2 (studs)....................................................................................................................................10Figure 3 (gasket)..................................................................................................................................10Figure 4 (valves)...................................................................................................................................11Figure 5 (piston )..................................................................................................................................12Figure 6 (piston rings)..........................................................................................................................13Figure 7 (connecting rod)....................................................................................................................14Figure 8 (crank shaft)...........................................................................................................................14Figure 9 (camshaft)..............................................................................................................................15Figure 10 (fuel injector).......................................................................................................................16Figure 11 (turbo charger).....................................................................................................................17Figure 12 ( intake stroke).....................................................................................................................19Figure 13 (compession stroke).............................................................................................................19Figure 14 (power stroke).....................................................................................................................20Figure 15 (exhaust stroke)...................................................................................................................20Figure 16 (two stroke )........................................................................................................................21

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3 Main text

3.1 Introducton

The diesel engine has been the engine of choice for heavy-duty applications in agriculture, construction, industrial, marine unit and on high way.

The diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine.

The injector on a diesel engine is its most complex component and has been the subject of a great deal of experimentation -- in any particular engine it may be located in a variety of places. The injector has to be able to withstand the temperature and pressure inside the cylinder and still deliver the fuel in a fine mist. Getting the mist circulated in the cylinder so that it is evenly distributed is also a problem, so some diesel engines employ special induction valves, pre-combustion chambers or other devices to swirl the air in the combustion chamber or otherwise improve the ignition and combustion process.

The main differences between the gasoline engine and the diesel engine are:

A gasoline engine intakes a mixture of gas and air, compresses it and ignites the mixture with a spark. A diesel engine takes in just air, compresses it and then injects fuel into the compressed air. The heat of the compressed air lights the fuel spontaneously.

A gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 to as high as 25:1. The higher compression ratio of the diesel engine leads to better efficiency.

Gasoline engines generally use either carburetion, in which the air and fuel is mixed long before the air enters the cylinder, or port fuel injection, in which the fuel is injected just prior to the intake stroke (outside the cylinder). Diesel engines use direct fuel injection -- the diesel fuel is injected directly into the cylinder.

One big difference between a diesel engine and a gas engine is in the injection process. Most car engines use port injection or a carburetor rather than direct

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injection. In a car engine, therefore, all of the fuel is loaded into the cylinder during the intake stroke and then compressed. The compression of the fuel/air mixture limits the compression ratio of the engine -- if it compresses the air too much, the fuel/air mixture spontaneously ignites and causes knocking. A diesel compresses only air, so the compression ratio can be much higher. The higher the compression ratio, the more power is generated.

The four strokes of the internal combustion engine are as follows (and in order): Intake, Compression, Power, and Exhaust. These four strokes require two revolutions of the crankshaft. The process continuously repeats itself during the operation of the engine. So, if a four-cylinder engine requires two complete revolutions of the crankshaft to ignite all of its cylinders.

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3.2 Historical backgroundThe Suez Canal , located in Egypt, is a 101 mile (163 km) long canal that connects the Mediterranean Sea with the Gulf of Suez, a northern branch of the Red Sea. It officially opened in November 1869.

3.2.1 Suez Canal Construction HistoryAlthough the Suez Canal wasn't officially completed until 1869, there is a long history of interest in connecting both the Nile River in Egypt and the Mediterranean Sea to the Red Sea. It is believed that the first canal in the area was constructed between the Nile River delta and the Red Sea in the 13th Century B.C.E. During the 1,000 years following its construction, the original canal was neglected and its use finally stopped in the 8th Century.

The first modern attempts to build a canal came in the late 1700s when Napoleon Bonaparte conducted an expedition to Egypt. He believed that building a French controlled canal on the Isthmus of Suez would cause trade problems for the British as they would either have to pay dues to France or continue sending goods over land or around the southern part of Africa. Studies for Napoleon's canal plan began in 1799 but a miscalculation in measurement showed the sea levels between the Mediterranean and the Red Seas as being too different for a canal to be feasible and construction immediately stopped.

The next attempt to build a canal in the area occurred in the mid-1800s when a French diplomat and engineer, Ferdinand de Lesseps, convinced the Egyptian viceroy Said Pasha to support the building of a canal. In 1858, the Universal Suez Ship Canal Company was formed and given the right to begin construction of the canal and operate it for 99 years, after which time, the Egyptian government would take over control of the canal. At its founding, the Universal Suez Ship Canal Company was owned by French and Egyptian interests.

Construction of the Suez Canal officially began on April 25, 1859. It opened ten years later on November 17, 1869 at a cost of $100 million.

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3.2.2 Suez Canal Use and ControlAlmost immediately after its opening, the Suez Canal had a significant impact on world trade as goods were moved around the world in record time. In 1875, debt forced Egypt to sell its shares in ownership of the Suez Canal to the United Kingdom. However, an international convention in 1888 made the canal available for all ships from any nation to use.

Shortly thereafter, conflicts began to arise over use and control of the Suez Canal. In 1936 for example, the U.K. was given the right to maintain military forces in the Suez Canal Zone and control entry points. In 1954, Egypt and the U.K. signed a seven year contract that resulted in the withdrawal of British forces from the canal area and allowed Egypt to take control of the former British installations. In addition, with the creation of Israel in 1948, the Egyptian government prohibited the use of the canal by ships coming and going from the country.

Also in the 1950s, the Egyptian government was working on a way to finance the Aswan High Dam. Initially it had support from the United States and the U.K. but in July 1956, both nations withdrew their support and the Egyptian government seized and nationalized the canal so passage fees could be used to pay for the dam. On October 29 of that same year, Israel invaded Egypt and two days later Britain and France followed on grounds that passage through the canal was to be free. In retaliation, Egypt blocked the canal by intentionally sinking 40 ships. These events were known as the Suez Crisis.

In November 1956, the Suez Crisis ended when the United Nations arranged a truce between the four nations. The Suez Canal then reopened in March 1957 when the sunken ships were removed. Throughout the 1960s and 1970s, the Suez Canal was closed several more times because of conflicts between Egypt and Israel.In 1962, Egypt made its final payments for the canal to its original owners (the Universal Suez Ship Canal Company) and the nation took full control of the Suez Canal.

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3.2.3 The Suez Canal TodayToday, the Suez Canal is operated by the Suez Canal Authority. The canal itself is 101 miles (163 km) long and 984 feet (300 m) wide. It begins at the Mediterranean Sea at Point Said flows through Ismailia in Egypt, and ends at Suez on the Gulf of Suez. It also has a railroad running its entire length parallel to its west bank.

The Suez Canal can accommodate ships with a vertical height (draft) of 62 feet (19 m) or 210,000 deadweight tons. Most of the Suez Canal is not wide enough for two ships to pass side by side. To accommodate this, there is one shipping lane and several passing bays where ships can wait for others to pass.

The Suez Canal has no locks because Mediterranean Sea and the Red Sea's Gulf of Suez have approximately the same water level. It takes around 11 to 16 hours to pass through the canal and ships must travel at a low speed to prevent erosion of the canal's banks by the ships' waves.

3.2.4 Significance of the Suez CanalIn addition to dramatically reducing transit time for trade worldwide, the Suez Canal is one of the world's most significant waterways as it supports 8% of the world's shipping traffic and almost 50 ships pass through the canal daily. Because of its narrow width, the canal is also considered a significant geographic chokepoint as it could easily be blocked and disrupt this flow of trade.

Future plans for the Suez Canal include a project to widen and deepen the canal to accommodate the passage of larger and more ships at one time.

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3.3 Main component of Diesel engine:3.3.1 Cylinder Head:-The cylinder head (or cylinder cover) is bolted to the top of the engine block and forms a gas tight seal over the end of each cylinder. The head may be cast as a separate head to cover each cylinder as is usual with the larger engines or in the case of smaller engines a single casting covering all cylinders. A number of engine parts that are essential to engine operation may be found in or attached to the cylinder head. The cylinder head for a 4-stroke cycle engine will house intake and exhaust valves, valve guides, and valve seats. The cylinder head will also carry the valve rocker arm assembly, fuel injection valves, heater plugs, the cover for the rocker gear as well as providing for the flow of:- cooling water to essential areas of the head, air supply for combustion and discharged exhaust gases.

Maintenance:-

Remove cylinder by sliding it up over the four stud.

In the case of v-twin engines, the cylinders used on air cooled units are interchangeable as a new part, but if they are to be used again, the should be suitably marked to ensure they will be replaced in their respective left and right hand position.

Remove the gudgeon pin cylinder and push gudgeon pin out of the piston, remove piston from connecting rod, in the case of v-twin engines, mark the piston to ensure correct replacement in their respective bores.

3.3.2Cyl

inder Head Gasket:-A gas tight seal between the cylinder head and the block depends upon surfaces being level and smooth, good quality gaskets, and the correct tightness (torque settings) of the head studs.

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Figure 1( cylinder head)

3.3.2.1 Stud:-Cylinder head studs are manufactured from round rod, generally of alloy steel. Threads are cut on both ends. The threads that screw into the block are generally made with finer threads than those on the nut end. This design allows for a tighter fit in the block, which keeps the stud from loosening when the stud nut is removed.

Figure 2 (studs)

3.3.2.2 Gasket:-Gaskets are used to provide a seal between two surfaces. The type of duty may vary greatly from the somewhat rough surfaces of water pipe flanges to the carefully ground faces of high pressure superheated steam pipes; from the valve cover on a cylinder head to the highly polished surfaces of hydraulic pump components. Each duty requires the correct type and thickness of material so it is important to understand the properties of the various gasket materials and the exact nature of the duty

Maintenance:-

When the gasket has leakage it must be removed and replaced and must be ensured, and stud are replaced when it brokedown.

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Figure 3 (gasket)

3.3.3 Valves:-All four-stroke internal combustion engines employ valves to control the admittance of fuel and air into the combustion chamber. Two-stroke engines use ports in the cylinder bore, covered and uncovered by the piston, though there have been variations such as exhaust valves.

3.3.3.1 Piston Engine Valve:-

In piston engines, the valves are grouped into 'inlet valves' which admit the entrance of fuel and air and 'outlet valves' which allow the exhaust gases to escape. Each valve opens once per cycle and the ones that are subject to extreme accelerations are held closed by springs that are typically opened by rods running on a camshaft rotating with the engines' crankshaft.

3.3.3.2 Control Valve:-Continuous combustion engines—as well as piston engines—usually have valves that open and close to admit the fuel and/or air at the startup and shutdown. Some valves feather to adjust the flow to control power or engine speed as well.

3.3.4 Piston:-A piston is a component of reciprocating engines. It is located in a cylinder and is made gas-tight by piston rings. Its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and or connecting rod. In two-stroke engines the piston also acts as a valve by covering and uncovering ports in the cylinder wall.

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Figure 4 (valves)

Figure 5 (piston )

Maintenance:-

If the piston has breakdown and has a leak, it must be replaced with another piston with the same dimension to ensure that the piston will work normally.

3.3.5 PistonRing:-Piston rings perform three functions: seal the cylinder, distribute and control lubricating oil on the cylinder wall, and transfer heat from the piston to the cylinder wall. All rings on a piston perform the latter function, but two general types of rings compression and oil are required to perform the first two functions.

Figure 6 (piston rings)

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3.3.5.1 Oil Ring:-Although oil rings come in a large variety of designs, they must all do two things:

1. Distribute enough oil to the cylinder wall to prevent metal to metal contact.

2. Control the amount of oil distributed.

3.3.5.2 CompressionRing:-The principal function of compression rings is to seal the cylinder and combustion space so that the gases within the space cannot escape until they have performed their function. Some oil is carried with the compression rings as they travel up and down the cylinder for lubrication. Most compression rings are made of gray cast iron.

Maintenance:-

When the piston ring leak it must be removed and replaced and must ensure when replaced that it has the same dimension of the old ring and ensure it is put at the right place on the piston and two ring opening are opposite to each other.

3.3.6 Connecting Rod:-The connecting rod or connecting rod connects the piston to the crank or crankshaft. Together with the crank, they form a simple mechanism that converts reciprocating motion into rotating motion.

As a connecting rod is rigid, it may transmit either a push or a pull and so the rod may rotate the crank through both halves of a revolution, Piston pushing and piston pulling. Earlier mechanisms, such as chains, could only pull. In a few two-stroke engines, the connecting rod is only required to push.

Maintenance:-

Remove the inspection cover on the side of the crank case which provides access to connecting rod big end.

Replace the connecting rod bolts through the exposed opening in the cover and remove them, then remove the connecting rod upwards through the cylinder bore.

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Figure 7 (connecting rod)

3.3.7 Crank Shaft:-The crankshaft changes the movement of the piston and the connecting rod into the rotary motion required to drive such items as reduction gears, propeller shafts, generators, or pumps. As the name implies, the crankshaft consists of a series of cranks (throws) formed as offsets in a shaft. The crankshaft is subjected to all the forces developed in an engine. Because of this, the shaft must be of especially strong construction. It is usually machined from forged alloy or high carbon steel. The shafts of some engines are made of cast-iron alloy. Forged crankshafts are nitride (heat-treated) to increase the strength of the shafts and to minimize wear.

Maintenance:-

Remove the nuts holding the main bearing plate flywheel side and remove the plate using two forcing screws .

At the first time we used the lathe to repair the shaft and put it back in the engine, and more over until it reaches the minimum allowable thickness so, it will be replaced in its next overhaul

3.3.8 Camshaft:-

Figure 9 (camshaft)

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Figure 8 (crank shaft)

It transmit the cam action of the crankshaft for the valves to open and close in the right time as needed. The relationship of camshaft and crankshaft is very important to an engine. The valves control the flow of air intake and exhaust gasses. For this purpose camshaft is connected to crankshaft either directly by a timing gear, by a timing belt or by a timing chain. Depending on the position of the camshaft, the cams operate the valves directly or by the use of a push rod and rocker arm. Direct operation of the cam to the valve is much simpler valve mechanism. It leads to fewer parts needed and which means fewer mechanism to fail. It will require that the camshaft is to be positioned at the top of the cylinder.

Maintenance:-

The camshaft replace after a long time of using because it is not broke down easily as there are no high stress on it.

3.3.9 Cooling system:-Combustion generates a great deal of heat, and some of these transfers to the walls of the engine. Failure will occur if the body of the engine is allowed to reach too high a temperature; either the engine will physically fail, or any lubricants used will degrade to the point that they no longer protect the engine. The lubricants must be clean as dirty lubricants may lead to over formation of sludge in the engines, Cooling systems usually employ air (air-cooled) or liquid (usually water) cooling.

3.3.10 Fuel injection:-Fuel injection is a system for admitting fuel into an internal combustion engine. It has become the primary fuel delivery system used in automotive engines, direct injection diesel engines have injectors mounted at the top of the combustion chamber. The injectors are activated using one of two methods - hydraulic pressure from the fuel pump, or an electronic signal from an engine controller.

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Maintenance:-

Remove the injector form the engine and then replace it, If its tested and found not spraying well

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Figure 10 (fuel injector)

3.3.11 Turbo Charger:-A turbocharger is a turbine-driven forced induction device that increases an engine's efficiency and power by forcing extra air into the combustion chamber. This improvement over a naturally aspirated engine's output results because the turbine can force more air, and proportionately more fuel, into the combustion chamber than atmospheric pressure alone.

Figure 11 (turbo charger)

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3.3.12 Lubrication System:-

The movement of various engine parts under high speed and load conditions creates the requirement for an engine lubrication system. Without some lubricant, friction between parts would quickly wear and generate heat causing severe engine damage and eventually seizure. A number of other lubrication system functions, while not obvious, are critical to good engine operation and durability. Lubrication systems in a diesel engine accomplish the following tasks:

1) Maintain oil film between piston rings and cylinder wall2) Provide proper lubrication of camshaft valve gear3) 3) Provide oil film between shafts and bearing surfaces at main, crank

pin wrist pin thrust bearings and all other bearing.4) 4. Assists sealing of the combustion chamber by forming a film between

the piston rings and the cylinder wall. 5) 5. Absorbs shock loads between bearings and gears thus, cushioning and

protecting engine parts while minimizing engine noise production. 6) 6. Stores an adequate supply of oil for lubricating internal engine parts. 7) 7. Minimizes corrosion of internal engine components

lubrication system components. o Oil pan : it is the reservoir for the oil, located in the bottom cover of

the engine.o Oil Pump : it supply oil under pressure. It draws oil from the reservoir to

the oil nozzles. bearings, and other parts that needs lubrication.

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3.4 4 stroke

3.4.1 The Intake Stroke:On the intake stroke, the intake valve has opened. The piston is moving down, and a mixture of air and vaporized fuel is being pushed by atmospheric pressure into the cylinder through the intake valve port.

3.4.2 The Compression Stroke:After the piston reaches the lower limit of its travel, it begins to move upward. As this happens, the intake valve closes. The exhaust valve is also closed, so the cylinder is sealed. As the piston moves upward, the air/fuel mixture is compressed. On some small high compression engines, by the time the piston reaches the top of its travel, the mixture is compressed to as little as one-tenth its original volume. Thus, the compression of the air/fuel mixture increases the pressure in the cylinder. The compression process also creates the air/fuel mixture to increase in temperature.

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Figure 12 ( intake stroke)

Figure 13 (compession stroke)

3.4.3 The Power Stroke:As the piston reaches the top of its travel on the compression stroke, an electric spark is produced at the spark plug. The ignition system delivers a high voltage surge of electricity to the spark plug to create the spark. The spark ignites the air/fuel mixture. The mixture burns rapidly and cylinder pressure increases to as much as (600psi). All of this pressure against the piston forces it down in the cylinder. The power impulse is transmitted down through the piston, through the piston rod (connecting rod), and to the crankshaft. The crankshaft is rotated due to the force.

3.4.4 The Exhaust Stroke:As the piston reaches the bottom of its travel, the exhaust valve opens. Now, as the piston moves up on the exhaust stroke, it forces the burned gases out of the cylinder through the exhaust port. When the piston reaches the top of its travel, the exhaust valve closes, and the intake valve opens. The cycle repeats again with the intake stroke. The four strokes are continuously repeated during the operation of the engine.

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Figure 14 (power stroke)

Figure 15 (exhaust stroke)

3.5 2 stroke:

A two-stroke or two-cycle engine is a type of internal combustion engine which completes a power cycle in only one crankshaft revolution and with two strokes, or up and down movements, of the piston in comparison to a four-stroke engine which uses four strokes. This is accomplished by the end of the combustion stroke and the beginning of the compression stroke happening simultaneously and performing the intake and exhaust or scavenging functions at the same time.

Figure 16 (two stroke )

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4 References

1. Volvo Marine Diesel Engine2. http://actualrepair.com/how-to-overhaul-a-diesel-engine/

(20/11/2014)3. Diesel workshop at Suez Canal Authority4. http://geography.about.com/od/specificplacesofinterest/a/

suezcanal.htm (20/11/2014)5. http://www.suezcanal.gov.eg/ (20/11/2014)6. http://en.wikipedia.org/wiki/

Component_parts_of_internal_combustion_engines (20/11/2014)

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