These segments fit the engines, Dirt bike, LIFAN 140cc, suitable for piston diameter of 55mm.
the segmentation of an internal combustion engine has the task of sealing the piston in the cylinder. The segmentation helps to ensure even cooling of the piston crown, the transfer of heat to the shirt cooled. You can also spread a thin layer of oil (a few µm) on the t-shirt to limit the wear and tear. Finally, it prevents the return flow of oil in the upper edge of the cylinder.