Manley Valve Stem Oil Seal, SEALS-5/16 STEM

Manley Performance valve stem oil seals are what you need when you're rebuilding an engine or just replacing worn-out seals. These seals are designed to fit 5/16 inch valve stems, a common size in many performance and stock applications. Their job is critical: they prevent oil from the valve train from leaking down into the combustion chamber, which can cause blue smoke out the exhaust, fouled spark plugs, and increased oil consumption.

Manley is known for making well-built internal engine components, and these seals are no exception. They are made to handle the heat and stress inside an engine. When you're putting an engine back together, especially if you're going through the heads, replacing these seals is a straightforward step that makes a big difference in how the engine runs and how clean it burns. Make sure you have the right tool to install them so you don't damage the seal or the valve guide.