Polini segment chromé MBK 51 H2O d.39mm

piston ring

Piston rings are sealing elements. They are inserted into the grooves of the piston to ensure sealing between the piston and the cylinder wall. Piston rings vary in size and shape and can be chrome-plated or cast iron, depending on the type of cylinder.

2-stroke piston Ring

The upper ring (often chrome-plated) is fireproof and seals the combustion chamber. The lower ring provides lubrication to the cylinder liner. 1-ring pistons perform both functions, but this results in a shorter service life.

4-stroke piston Rings

The upper ring also has the function of sealing the combustion chamber, while the middle ring collects excess oil and contributes to engine compression. The lower ring, known as the oil scraper ring, prevents engine oil from entering the combustion chamber.

Piston rings play a crucial role in the proper functioning and service life of the cylinder, whether on a motorcycle, scooter or moped.