Diesel Engine Basics Quiz

Study Notes

In a 4-stroke engine, the camshaft operates at half the speed of the crankshaft.

Internal components of the inline pump are filled with diesel fuel, serving to cool and lubricate moving parts.
The plunger in the inline pump has two motions: reciprocating and rotary.
Reciprocating motion determines the plunger's stroke, while the rotary motion controls the effective stroke, thus modifying the amount of injected fuel.
Fuel enters through the inlet port; as the plunger moves up, pressure builds and fuel is injected into the combustion chamber via the nozzle.
When the plunger's helix opens the inlet port, fuel escapes, causing a loss of pressure and stopping injection.
Effective stroke is defined as the distance from inlet port closure to spill port opening.
Different helix configurations influence fuel injection timing and quantity:
- Variable closure and constant end of injection.
- Constant closure and variable end of injection.
- Both ends variable, allowing for adjustments to both timing aspects.

This pump features a single plunger that meters and distributes fuel to all engine cylinders, suitable for up to 6 cylinders.
Commonly used in small, high-speed diesel engines like passenger cars and light trucks.
Included components of a distributor fuel injection pump:
- Vane-type fuel supply pump, creating pressure.
- High-pressure pump to distribute fuel.
- Mechanical governor for modifying pump speed.
- Electromagnetic shutoff valve for fuel supply control post-engine shutoff.
- Timing device to adjust delivery start based on engine speed and load.

An integrated vane pump draws fuel from the tank into the high-pressure chamber.
The plunger combines rotary and reciprocating motions to manage fuel intake and distribution.
The effective stroke of the plunger correlates to accelerator pedal position, impacting fuel quantity delivered.
The number of cam lobes matches the number of engine cylinders, aligning plunger strokes with cylinder requirements.

The system includes sensors, an ECU, and actuators for efficient operation.
Solenoid actuators adjust fuel injection quantities and timing by managing cutoff ports and pressure applied to timing devices.

Combines the fuel-injection pump and nozzle into a single unit for each cylinder.
Capable of achieving maximum injection pressure around 2,200 bar.
Electronic control manages injection timing and duration, minimizing hydraulic delays for efficient operation.
Nozzle design impacts fuel atomization and optimal distribution within the combustion chamber.

Diesel injectors consist of a nozzle holder and injection nozzle.
Pintle nozzles are used in IDI diesel engines and vary in design: standard, throttling, and flatted.
Hole-type nozzles, used in DI diesel engines, are categorized as seat hole and sac-hole nozzles.
Differences in the nozzle types are primarily based on the geometry of the pintle, influencing performance and combustion efficiency.