Unburned fuel emissions
& Exhaust leaks

A primary function of the engine piston rings is to seal the combustion chamber from the crankcase. If excess combustion gases slip past the ring pack, they can enter the crank case and cause rapid deterioration of the crankcase lubricant. When these combustion gases escape the crank case they will bypass any exhaust gas treatment unless they are routed back to the intake manifold. Poorly sealing engine piston rings will eventually lower the compression ratio of the engine and reduce the fuel efficiency of the engine.

Piston rings will generally go through a break-in period where they slowly wear down the surface irregularities that allow a certain amount of combustion gases to slip past the rings. After the rings are properly broken-in they should normally function reliably for a long period. As the rings slowly wear out however, the end gap will grow, steadily increasing gas leakage and reducing the efficiency of the seal. When the leakage leads to unacceptable blow-by or poor fuel efficiency (and high oil consumption) the rings will have to be replaced.

By using Cooper’s Mo2 rings, thanks to the dual purpose coating, the break-in period will be much quicker and the long time wear rate will be slower leading to a better performing piston ring seal for a longer time compared to other types of piston ring coatings.