What is the basic function of a piston in an engine?

The basic function of a piston in an engine is to receive the force of the expanding gases caused by combustion. When fuel and air are ignited in the engine's combustion chamber, the reaction generates high-pressure gases that push down on the piston. This force is what drives the piston down the cylinder, converting the energy from combustion into mechanical energy that ultimately powers the vehicle. This process is essential for the engine's operation, as it is the expansion of gases that propels the piston and, in turn, the crankshaft, leading to vehicle movement.

The other functions mentioned, such as cooling the engine or controlling the air-fuel mix, are handled by other components. The piston does not serve as a support for the cylinder head; instead, it moves within the cylinder to perform its primary purpose in the combustion process.