Comments on Valve Stem Seals for Engine Application in Small Size Passenger Cars

Valve stem seals have been used for the various valve stem application of automotive engines by establishing the certain lubricating status between valve stems and valve guides. It is necessary that valve stem seals have stable controlled oil leakage characteristics relative to variables such as oil viscosity, shaft speed and shaft surface roughness. The practical aspect of the characteristics of the controlled oil leakage on valve stem seals for engine application in small size U.S. and Japanese passenger cars have been discussed in this paper.