Positive Stop PTFE Seals
PTFE; Seal; Valve Guide; Valve Guide Seal; Valve Stem Seal; Valve Seals; 5/16" Valve Seals; 11/32" Valve Seals; .530" Valve Seal; Umbrella; O-Ring Seals; Viton Seals; 8 mm Seals
COMP's Positive Stop PTFE valve seals offer more clearance for dual springs with better sealing than o-ring or umbrella seals. These 503 seals have a .630" outer diameter and fit applications with 11/32" valves and .530" 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. O-ring seals use the standard retainer and oil splash shield. Umbrella seals are normally used when a larger-than-stock diameter spring is used; in the case of a double spring, positive stop PTFE seals are used. There is also a smaller diameter Viton seal available for triple spring applications. O-rings and umbrella seals require no machining, but PTFE seals require the heads to be disassembled so the top guides can be machined with a special .530" diameter cutter. Whenever you're planning an overhaul or cam change, don't forget the valve seals!Features:
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