A gasket fills the small irregularities between two mating surfaces so fluids and pressure stay where they belong. Each joint on an engine has different demands — temperature, pressure, movement and the fluid being sealed — so gaskets are designed and made from different materials for each location.
The Main Engine Gaskets
- Head gasket: seals combustion pressure, coolant and oil between the head and block. The most demanding sealing job in the engine.
- Intake manifold gasket: seals air and fuel, and on many engines coolant, between the manifold and head.
- Exhaust manifold gasket: withstands very high temperatures and the expansion and contraction of the manifold.
- Valve cover gasket: seals oil at the top of the engine, often with spark plug tube seals.
- Oil pan gasket: seals the oil sump to the bottom of the block.
- Timing cover gasket: seals the front of the engine around the timing drive.
- Water pump and thermostat housing gaskets: seal the cooling system.
- Front and rear main seals, camshaft seals: seal around rotating shafts rather than between flat surfaces.
Common Gasket Materials
- Multi-layer steel (MLS): layers of embossed steel with coatings; common for head gaskets and exhaust joints on modern engines.
- Composite: fiber or graphite facings bonded to a steel core; used on many head and manifold gaskets.
- Molded rubber: precision rubber seals, often in a plastic or metal carrier, used for valve covers, intakes and oil pans.
- Cork-rubber: conforms well to stamped-steel covers on older engines.
- Fiber and paper: used for low-pressure joints such as some water pump and thermostat housings.
- Formed-in-place sealant (RTV): used where the manufacturer specifies a liquid sealant instead of a cut gasket.
Matching Gasket to Engine
Using the gasket designed for the specific engine and joint matters. Material, thickness, coatings and bead design all affect clamp load and sealing. A gasket that fits the bolt pattern is not necessarily correct for the application.
Eversealed Technologies
Every Evergreen gasket is engineered with Eversealed Technologies, matching the right sealing material to each engine for dependable performance. Use the Evergreen eCatalog to find complete gasket sets and individual gaskets for your engine. Browse Evergreen gasket sets and seals.
