How do pistons work in a car engine?

A piston is a cylindrical-shaped component that moves up and down inside a cylinder in an engine. It is connected to the crankshaft by a connecting rod, and its movement converts the up-and-down motion of the piston into the rotary motion of the crankshaft.

The piston has a flat top and a slightly concave bottom. The top of the piston is exposed to the combustion chamber, where the air-fuel mixture is burned. The bottom of the piston is exposed to the crankcase, where the oil is stored.

The piston has two main functions:

To seal the combustion chamber and prevent the air-fuel mixture from escaping.
To convert the up-and-down motion of the piston into the rotary motion of the crankshaft.

The piston is made of a lightweight material, such as aluminum or steel. It is coated with a thin layer of oil to reduce friction between the piston and the cylinder wall.

The piston is moved up and down inside the cylinder by the connecting rod. The connecting rod is attached to the crankshaft, which rotates the crankshaft when the piston moves up and down.

The piston’s movement is controlled by the valves in the engine. The valves open and close to allow the air-fuel mixture to enter the combustion chamber and the exhaust gases to escape.

The four-stroke cycle

The piston moves up and down inside the cylinder in a four-stroke cycle. The four strokes are:

Intake stroke: The intake valve opens and the piston moves down, drawing the air-fuel mixture into the combustion chamber.
Compression stroke: The intake valve closes and the piston moves up, compressing the air-fuel mixture.
Power stroke: The spark plug ignites the air-fuel mixture, causing it to burn. The burning gases expand, pushing the piston down.
Exhaust stroke: The exhaust valve opens and the piston moves up, pushing the exhaust gases out of the combustion chamber.

The four-stroke cycle is repeated over and over again, powering the engine.

Conclusion

The piston is a key component in a car engine. It is responsible for sealing the combustion chamber, converting the up-and-down motion of the piston into the rotary motion of the crankshaft, and controlling the flow of air and fuel into and out of the combustion chamber.