Published on July 7th, 2017 | by Guest


What are the Various Parts in a Diesel Engine Functions?

As you are trying to figure out the function of the diesel engine and generator in the car, you must know the individual engine parts for a better understanding of the mechanics. The car engine may have 2 to 8 cylinders depending on the power of the car. A small car will have 2 to 4 cylinders, while a medium sized car may have 6 cylinders and a bigger vehicle may have 8. The various configurations of the diesel engine parts will bring in different power output, smoothness of operation, costing of the car, etc. The engine parts are described below.


There are inlet and outlet valves in an engine. The inlet valves let in air and fuel, and the outlet valves let out the exhaust fumes. Both have high importance in keeping the engine running at optimum temperatures. When combustion and compression take place, then both the valves stay closed. The combustion chamber remains sealed at that time.


The piston moves up and down and is a vital part of the cylinder. It comprises of many parts.

Piston Rings

The edges, both outer and inner in a cylinder have a sliding seal made of the piston rings. The piston rings have two important roles, and they are:

  • The rings seal the valves, and hence the exhaust gases or the fuel or air mixture cannot leak out to the sump during compression and combustion.
  • The oil in the sump is not leaked into the combustion area, and hence the wastage of fuel by being burnt and lost can be avoided.

When these rings are worn off in an old engine of a used car, then the oil is lost and burnt and wasted. Thus, the car’s fuel consumption increases.

Connecting Rod

The piston and crankshaft are connected by the connecting rod. The power of rotation at both ends lets it change angles flexible as the crankshaft rotates and the piston moves.


The job of this part of the diesel engine is to convert the up and down motion of the piston into a rotational motion.


The sump contains some oil and surrounds the crankshaft.

Difference in Parts of a Diesel Engine

There are many differences between diesel and fuel engines:

1. The spark plus is missing in a diesel engine. That’s because the fuel-air mixture is ignited not through a spark, but by a simple compression.

2. The air drawn into a petrol engine is different in different strokes and varies in volume. But in a diesel engine, the air drawn is fixed with each stroke. There is only one inlet valve in the diesel engine. The butterfly valve and carburetor are not present in a diesel engine, unlike the petrol engine.

These makes the difference in the parts of a diesel engine car or vehicle.

How the Parts Make the Diesel Engine Work

  • The piston reaches the end through an induction stroke while the inlet valve closes.
  • Other pistons powered by the piston pressure and the flywheel momentum, reaches the cylinder top to compress the air to a volume which is 20 times lower than the original.
  • When the piston is at the top position, a small amount of fuel is injected into the combustion chamber.
  • The air-fuel mixture gets ignited from the heat generated by the high compression.
  • The burning air expands and forces the piston downward to turn the crankshaft.
  • While the piston goes for the exhaust stroke, the exhaust valve is opened. As a result, the exhaust gases travel through the exhaust pipe, and the end of the stroke makes the cylinder ready to take fresh air again.

Hopefully, the above mentioned information helps you to understand about various parts in a diesel engine. Let’s go here to get more details.

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