COMP Cams Valve Seals 3/8in PTFE W/.500in - 512-12

Set of 12 PTFE Valve Seals for .500" Guide Size, 3/8" Valve Stem

Application: Engines w/ 0.500" OD Valve Guides and 3/8" Valve Stems

COMP's Positive Stop PTFE valve seals offer more clearance for dual springs with better sealing than o-ring or umbrella seals. These 512 seals have a .600" outer diameter and fit applications with 3/8" valves and .500" OD valve guides.

COMP Cams offers a complete line of valve stem Seals, from the stock GM "O-Ring" to the positive-stop PTFE Seal. These Seals are a must to keep unwanted oil from entering the combustion chamber through the clearance in the valve guides. The "O-Ring" Seals use the standard retainer and oil splash shield. The umbrella Seal is normally used when a larger-than-stock diameter spring is used, in the case of a double spring, the positive-stop PTFE Seal is used. We also have a smaller diameter Viton Seal available for triple spring Applications.

COMP Cams offers a complete line of valve stem oil seals, from the stock GM o-ring to the positive-stop PTFE seal. These seals are a must to keep unwanted oil from entering the combustion chamber through the clearance in the valve guides. The o-ring seals use the standard retainer and oil splash shield. The umbrella seal is normally used when a larger than-stock diameter spring is used, and in the case of a double spring, the positive stop PTFE seal is used. Smaller diameter Viton seals are also available for triple spring applications. Both the o-ring and the umbrella seals require no machining, but when using the PTFE seal it is necessary to disassemble the heads and machine the top of the guide with a special cutter.