 The role of valve stem seal is to limit the amount of oil which enters the cylinders by way of the valve guides. At the same time, the seal must let a certain amount of oil into lubricate valve stem and valve guide in order to avoid excessive wear and/or sticking.
The first seals were made of polyacrylic elastomer. As valve stem seal technology progressed, fluoro-eleastomers (FPM) became the material of choice.
 The valve stem seal aslo helps limit the pollution resulting from the combustion of the lubricant and the possiblecontamination and destruction of the catalytic converter by certain components present in the oil.
Valve stem seals type has VA3, VA9, also VA0, VA1, VA2, VA4, VA5, VA6, VA7 etc. |
