RETHINKING OEM EXHAUST FLANGE GASKETS
You want to seal that flange with an OE MLS gasket? Good luck! — The same conditions now exist in exhaust flange technology as when the first MLS head gaskets were being replaced under repair conditions. OEM MLS exhaust flange gaskets just can’t create a lasting seal on a warped, pot marked and irregular sealing surface that is not straight. The MLS gasket may provide an initial seal but after a few heat cycles and a short period of time, the embossment that is designed to seal the gasket no longer recovers and the irregular surface of the flange allows leak paths to develop and the MLS gasket will fail very prematurely. — stainless steel armor for a positive seal around the exhaust ports and a composite graphite gasket body material that is designed to fill in minor imperfections in the surface finish allows for a more robust clamp load sealing the exhaust ports. When the imperfections in the surface are eliminated, the seal will be maintained for the life of the gasket. — To prevent future failure you should use a gasket that has been engineered utilizing the materials and design for the real world repair environment. By the way, that OEM exhaust manifold gasket failed for a reason. If you don’t fix the cause or redesign the gasket, why would you expect a different outcome?
Engine Pro Technical Committee