Piston Rings Polini d.49mm Piaggio / Vespa 50cc 4-stroke

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.

Tuning Level: Sport

We categorize our products into different performance levels  Original, Sport, Racing and High End , so that our customers can choose the right parts for their setup. It is really important to combine parts that belong to the same tuning level, this is especially true for cylinders, crankshafts and exhausts.

The products listed under Sport yield better performance than Original parts. They may have technical differences, such as the use of higher quality materials, a larger displacement or a performance-enhancing design. They are suitable for everyday use and have a long service life.

Aluminium cylinders

Aluminium cylinders are more powerful than cast iron cylinders, but require more regular maintenance and must be combined with different components such as a reinforced crankshaft and a larger carburetor.

How to run in an aluminium cylinder?

Aluminium cylinders should be run in for about 200 kilometers , and you should use a fully synthetic engine oil.

Note: To ensure optimum performance and reliability, it is advisable to measure the squish clearance. Just have a look at our tutorial How to adjust squish clearance.