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How a Car Engine Works

Stephen Rampur
Knowing about car engines, how they work, and what parts are involved can really be interesting. Here is a basic guide on the working of an engine.
We drive cars everyday, but have we ever thought of how they work, and what makes the vehicle move? If you are a car lover, you would surely be excited to know more about car engines and the different parts of the engine.

Basic Parts of a Car Engine

Spark Plugs

In simple words, spark plugs are auto parts that help the engine start. They provide a spark to the air and fuel mixture, which results in combustion. If you want the engine to start and run smoothly, replacing the spark plugs at prescribed intervals is essential.


Pistons are components that are cylindrical in shape, and move in the cylinder in an upward and downward motion. The main job of the piston is to compress the air and fuel mixture that comes in the cylinder.

Piston Rings

These are rings present around the piston, which preclude the fuel and air mixture from going into the sump during the process of combustion. Moreover, they also do not let oil from the sump get into the combustion area.


In the engine, there are two types of valves, the intake valve and the exhaust valve. The intake valve opens at the appropriate time to let the fuel enter the combustion area, while the exhaust valve operates to let out the exhaust after combustion.


As the pistons move in the upward and downward direction, the crankshaft moves in a circular motion, adjusting with the up/down movements of the pistons connected to it.


The flywheel is situated behind the crankshaft. When you turn on the ignition, the starter releases a gear on it, which makes the engine start functioning.

Connecting Rod

This is a metal rod that maintains a connection between the crankshaft and the piston. Both its ends are not fitted tightly, so as to have a change in its angle when the piston moves and the crankshaft rotates.

Car Engine Mechanism

Do not get confused by looking at the complicated parts of the engine that make it run. The engine runs in a very simple manner. Essentially, there are four stages after which power is generated for the automobile to move. These four stages, also known as four strokes, are intake, compression, power, and exhaust.
The first intake stroke starts when the cylinder's intake valve opens to let the air and fuel mixture enter the cylinder for compression and combustion. When the valve opens, the piston moves in the downward direction which creates space for the mixture to enter the combustion area.
The second compression stroke is operational when both the intake as well as exhaust valves are closed, and the piston starts coming in the upward direction for compressing the mixture.
The third stage is the power stroke, where power is generated by igniting the mixture. As the piston comes up, compressing the mixture, the spark plug fires and ignites the mixture, causing the piston to move in the downward direction again, which ultimately produces power.
The fourth stage is the exhaust stroke, where leftover fumes are thrown out of the cylinder by the opening of the exhaust valve. To generate power to the engine, this whole process is repeated.
This is the basic manner in which an engine works. When you sit in your car, turn on the ignition, and start to drive, the mentioned process has started to run repeatedly in the engine, which is providing the motion to your vehicle.