What do piston compression rings do?

Piston compression rings play a critical role in sealing the combustion chamber. Their primary function is to maintain a tight seal between the piston and the cylinder wall, preventing the escape of combustion gases from the combustion chamber during the power stroke. This seal ensures that maximum pressure is achieved within the combustion chamber, allowing the engine to produce optimal power and efficiency.

By effectively sealing the combustion chamber, the rings help in maintaining engine performance and fuel economy while minimizing emissions. The design of the rings, which typically includes a slight outward tension, ensures they make consistent contact with the cylinder walls, adapting to any minor irregularities and maintaining the integrity of the seal throughout the engine's operation.