Viton Valve Seals - 11/32 Steel Body .500

The Viton Valve Seals - 11/32 Steel Body .500 by COMP CAMS (MPN 517-16) are precision engine components engineered for high-performance and street applications requiring reliable valve stem sealing. These positive-stop valve stem seals are designed for 11/32-inch valve stems operating in guide bores of 0.500 inches, making them essential maintenance and upgrade components for engine builders, mechanics, and performance enthusiasts. The set of 16 seals addresses the complete valve train on most small-block and mid-displacement engines, ensuring consistent compression and reducing blow-by across all cylinders.

Constructed with a steel body and Viton elastomer sealing element, these valve seals deliver superior resistance to heat, oil degradation, and chemical breakdown compared to standard rubber compounds. The positive-stop design prevents the seal from rotating or shifting during engine operation, maintaining critical contact with the valve stem and guide bore under all load and RPM conditions. Viton's synthetic fluorocarbon composition remains pliable across a wide temperature range, preserving sealing integrity from cold starts through peak combustion temperatures, while the steel backing provides structural support and prevents extrusion under high cylinder pressures.

These seals are ideal for engine rebuilds, performance cam upgrades, and high-mileage restores where factory seals have hardened or lost effectiveness. They fit OEM valve stem and guide dimensions across domestic V8, inline, and specialty engines with 11/32-inch stems and 0.500-inch guides—common in Chevrolet small-blocks, Ford Windsor and Cleveland platforms, and comparable performance builds. Installation requires removal of the valve spring and retainer; proper seating ensures optimal oil control and extends engine longevity by preventing valve guide wear and oil consumption.