What Does a Piston Do in a Car Engine?

Introduction

A piston is a cylindrical-shaped component that moves up and down within a cylinder in an engine. It is connected to the crankshaft by a connecting rod and is responsible for converting the reciprocating motion of the crankshaft into rotational motion. Pistons are made of lightweight materials such as aluminum or steel and are designed to withstand high temperatures and pressures.

Function of a Piston

The primary function of a piston is to compress the air-fuel mixture in the cylinder and then force it out of the cylinder during the power stroke. The piston moves up and down within the cylinder, creating a vacuum that draws the air-fuel mixture into the cylinder during the intake stroke. Once the air-fuel mixture is drawn into the cylinder, the piston moves up, compressing the mixture and increasing its pressure and temperature. At the top of the compression stroke, the spark plug ignites the air-fuel mixture, causing it to burn and expand. The expanding gases push the piston down, creating rotational motion in the crankshaft.

Types of Pistons

There are two main types of pistons: flat-top pistons and dome-shaped pistons. Flat-top pistons have a flat top surface, while dome-shaped pistons have a raised top surface. Dome-shaped pistons are used in high-performance engines because they provide a higher compression ratio, which can increase power output.

Materials Used for Pistons

Pistons are typically made of aluminum or steel. Aluminum pistons are lightweight and have a high thermal conductivity, which helps to dissipate heat from the piston. Steel pistons are stronger than aluminum pistons and can withstand higher temperatures and pressures.

Piston Rings

Piston rings are used to seal the gap between the piston and the cylinder wall. They prevent combustion gases from leaking out of the cylinder and oil from leaking into the combustion chamber. Piston rings are made of a variety of materials, including steel, cast iron, and graphite.

Piston Connecting Rod

The piston connecting rod is a link between the piston and the crankshaft. It converts the reciprocating motion of the piston into rotational motion in the crankshaft. Connecting rods are typically made of forged steel or aluminum and are designed to withstand high loads.

Conclusion

Pistons are essential components in a car engine. They play a vital role in converting the reciprocating motion of the crankshaft into rotational motion, which is used to power the vehicle. Pistons are made of lightweight materials such as aluminum or steel and are designed to withstand high temperatures and pressures.