Presentation 1

A PROGRESS PRESENTATION ON

COMPARATIVE ANALYSIS OF CARBURETOR AND FUEL

INJECTION SYSTEM(a case study of Apache 160)

Presented by :Netra Jung Karki (41066)Prabesh Poudel (41075)Prajwol Shrestha (41086)

November 24, 2010

INTRODUCTION TO THE TOPIC This project aims to carry out the study and analysis

of different parameters of carburetor and fuel injection fuel supply systems and also analyses the necessity of either of the systems for locally available motorbikes.

Carburetor is the earliest form of fuel supply mechanism to mix just the right amount of gasoline with air for engine combustion.

Replacing the carburetor, fuel injection system has been developed for reliable and efficient fuel supply to the combustion process using sensors and electronics.

OBJECTIVES To perform emission analysis between

carburetor and fuel injection system

Analysis of sound level, pick-up, power, efficiency and economy between the two systems with reference to Apache 160 model

Selection of best alternative

WHY APACHE 160 ? Bajaj Pulsar 220 DTS-Fi, Hero Honda Karizma ZMR,

Apache RTR 160 Fi, Yamaha FZ16, Yamaha YZF R15 have introduced fuel injection system in Nepal

Apache has got both systems in identical engine in terms of cc.

- Apache FI 160 (Fuel Injection system)- Apache RTR 160 (Carburetor System)

Apache FI 160(Fuel Injection)

Apache RTR 160(Carburetor)

CARBURETOR Earliest form of fuel supply mechanism for modern

automobile Essentially a tube with throttle plate, venturi and jet

Schematic Diagram of a simple or elementary carburetor

CARBURETOR....

All carburetors work on the “Bernoulli Principle” Air flowing through the throat of the carburetor will be at a

pressure less than atmospheric pressure, and related to the velocity (and hence to how much air is being fed into the engine).

A choke is simply a plate that can be maneuvered so that it completely (or very nearly) blocks off the carburetor throat at its entrance.

The more air that the engine pulls through the carburetor throat, the greater the pressure drop across the jet, and the more fuel that gets pulled in.

A motorcyle carburetor

FACTORS INFLUENCING CARBURETION

The engine speed; the time available for the preparation of the mixture.

The vaporization characteristics of fuel. The temperature of the incoming air The design of the carburetor.

TYPES OF CARBURETORS- Open choke type - Constant vaccum typeventuri is of fixed dimensions area of the air passage

is varied automaticallymetering is affected by varying the pressure drop across it pressure drop is kept

approximately constant

Basic forms of Carburetor

Updraught Downdraught Horizontal

FUEL INJECTION fuel is directly supplied to the cylinder in the

intake chamber. Sensors located in such engines will regulate the flow; electronic system

three basic sub-systems; fuel delivery , air induction , and the electronic control system

Schematic Diagram of simple EFI system

HISTORY OF FUEL INJECTION Electronic fuel injection had its beginnings in Italy by an engineer

named Ottavio Fuscaldo in late 1880s in 1949, Stuart Hillborn featured a fuel injected Offenhauser with

indirect injection system Chevrolet introduced the Rochester Ramjet in 1957 GM then in 1975 introduced the first mass produced domestic fuel

injection system on the 1976 model Cadillac Seville Later in 1980, the first digital computerized control was introduced for

Cadillac called Digital Fuel injection (DFI), originally conceptualized as a multipoint injection, with two fuel injectors

In 1982, Pontiac introduced the single injector throttle body system on its 2.5L 4 cylinder "iron duke" engine

A technological milestone was reached in 1985 with the introduction of the Multiport Fuel Injection on its 2.8L used in the Celebrity, Camaro, Cavalier, Citation and a multitude of other GM division vehicles

In 1989, the cold start injector was eliminated. In 1990, the mass air flow was eliminated and speed density control was introduced

OPERATION CYCLE OF ELECTRONIC FUEL INJECTION (EFI)

Air enters the engine through the air induction system Fuel injectors are arranged in the intake manifold behind each

intake valve The ECU pulses the injector by switching the injector ground

circuit on, off When the injector is turned on, it opens, spraying atomized fuel It mixes with the incoming air and vaporizes due to the low

pressures in the intake The ECU signals the injector to deliver just enough fuel to achieve

an ideal air/fuel ratio The ECU determines the basic injection quantity based upon

measured intake air volume and engine rpm. Depending on engine operating conditions, injection quantity will

vary

ADVANTAGES OF FUEL INJECTION WITH RESPECT TO CARBURETOR

Uniform Air/Fuel Mixture Distribution Highly Accurate Air/Fuel Ratio Control Superior Throttle Response and Power Excellent Fuel Economy With Improved Emissions

Control Improved Cold Engine Startability and Operation Simpler Mechanics, Reduced Adjustment

Sensitivity

TYPES OF FUEL INJECTIONS Throttle-body injection: Commonly known as TBI, this

system injects fuel at the throttle body. Continuous injection: fuel sprays continuously from

injector rather than getting pulsed every time a stroke is given to the engine.

Multi-point fuel injection: the fuel is injected into the intake port along the side of cylinder’s intake valve rather than a central point.

Central port injection: tubes along with valves are used to spray fuel at each intake rather than full throttle body.

Direct Injection: the nozzle used for injection is placed in the combustion chamber and the piston causes a depression when an initial combustion takes place.

RISKS OF FUEL INJECTION

Due to the high pressure developed in the engine, a fuel injection system causes some potential hazards

A residual pressure may remain in the engine even after the engine is turned off and it may cause an injury to the operator

PROGRESS...Work targeted for this semester Detail study of Carburetor and Fuel Injection Detail study about Emission standards Sound and Economic Analysis Progress report and Presentation

Work completed : Study of Carburetor and Fuel Injection Study about Emission standards (in progress..) Sound Analysis (in progress..)

Remaining Work :⇑ Economic analysis

CONCLUSION As, fuel injection system bikes has been

recently introduced in Nepal, we will find out the importance of it in present context.

provide the comparative data between power, economy, efficiency which can be used for different class of people for the bike selection.

Project is running smoothly..