This presentation was the result of a semester studying automotive engineering and systems.

1. Fuel Injectors MAE 442 Mitch Rieck, Arie van Eyk and Brandon Kaufman 12/9/2009

6. Types After the carburetor there are two main types of fuel injection, direct and indirect. The main difference between direct and indirect injection is the layout of the injection system, the indirect injection system actually has a small swirl chamber above the cylinder, where the fuel is injected, this chamber also contains the spark plug, which is needed to start the engine, the direct injection system has the injection nozzle actually fixed to the top of the combustion chamber, usually the piston on the engine with this type of injection system has a crown shape in the top to create the needed air/fuel mixture.

7. Indirect Injection Indirect injection is used on most automobiles today. Before the fuel enters the piston cylinder it mixes with the air in a separate chamber. When the correct pressure is reached it is released into the piston cylinder for combustion.

8. Open view diagram Indirect Fuel Injector

9. Exploded view diagram Needle Valve Multiport injector Compression Bushing Valve Spring Injector Housing Nose Cover

10. Direct Injection In a direct-injection system, the air and gasoline are not pre-mixed. Air comes in through the intake manifold, while the gasoline is injected directly into the cylinder. The piston head is curved to create a swirl at high pressures in order to ensure a balanced air-fuel mixture.

11. Open view diagram Direct Fuel Injector Photograph courtesy of Mitch Rieck Spray Tip Fuel Passageway Valve Spring Air Intake

17. Formulae (cont.)

19. Graphs

20. Graphs

21. Graphs