Valve Seals Viton Metal Jacket 3/8 x .625

The Cometic Gaskets Valve Seals Viton Metal Jacket 3/8 x .625 (part number 3198V-16) is a precision engine seal designed for applications requiring reliable valve stem sealing under high-temperature and high-pressure conditions. This set of 16 seals features Viton elastomer construction with a metal jacket, engineered to prevent oil leakage and maintain compression integrity in demanding engine environments.

These valve stem seals are engineered for a 0.373-inch valve stem with a 0.742-inch outer diameter and a 0.625-inch guide bore diameter. Viton material provides superior chemical resistance and thermal stability compared to standard rubber seals, maintaining elasticity across a wider temperature range. The metal jacket reinforces the seal geometry, resisting deformation under sustained pressure and preventing extrusion—critical factors in high-revving or forced-induction applications. Each seal in this 16-pack is manufactured to tight tolerances to ensure consistent fit and performance across your cylinder head.

These seals are used by engine builders, machine shops, and performance enthusiasts rebuilding cylinder heads for racing engines, street performance builds, and automotive restoration projects. Whether you're addressing worn seals in an existing engine or assembling a fresh short block, Cometic's valve stem seals provide the durability needed to control oil consumption and extend engine life. They fit applications where OEM seals have deteriorated or where enhanced thermal and chemical resistance is required.

Cometic Gaskets has established itself as a leader in precision sealing products for automotive and powersports applications. The Viton metal-jacket design represents a performance upgrade over standard rubber valve seals, particularly in boosted, nitrous, or high-rpm environments where seal failure can lead to costly engine damage. The 16-pack quantity accommodates complete cylinder head restoration with minimal waste, making this an economical choice for serious engine work.