The function of a first compression ring (top ring) is that it maintains a seal and prevents escape of burned gases and loss of pressure in the combustion chamber.
The function of a first compression ring (top ring) is that it maintains a seal and prevents escape of burned gases and loss of pressure in the combustion chamber.
The function of a second ring is that it is a compression ring and aids the top ring in sealing and cooling.
The function of oil control rings is that it prevents engine oil from going into the combustion chamber and returns excess lubricating oil off the cylinder wall through the return holes in the piston to the oil pan.
Piston rings are commonly made from cast iron. Cast iron retains the integrity of its original shape under heat, load, and other dynamic forces. Piston rings seal the combustion chamber, conduct heat from the piston to the cylinder wall, and return oil to the crankcase.
The lower cylindrical portion of the piston which improves piston cooling performance is called piston skirt.