In this article, you will learn what is a gasket, how it works? types of gaskets used in the engine, its properties and more.
Gasket and Types of Gaskets
In the engine, the gasket is placed between the cylinder head and cylinder block to prevent leakage, to ensure metallic tight fit joint and also to maintain compression in the cylinder. The gasket should be able to withstand the high pressure and extreme temperature.
Gaskets are found in
- Between the cylinder head and the cylinder block
- Between crankcase and oil pan.
- In the cylinder block and manifold.
Requirement/properties of the gasket as follows
- Conformity: The gaskets should conform to the mating surfaces which may have roughness or warpage.
- Resistance: It should have resistance to high pressures, extreme temperature and vibrations.
- Impermeability: The gasket must be impermeable to the fluid.
- Resistance to chemical attack: The gasket should have resistant to the chemicals such as fuel, coolant, products of combustion and engine oil.
- Provision of apertures: The gasket must have apertures for any studs, bolts, opening etc.,
Types of Gaskets
Following are some of the different types of gaskets:
- Cylinder head gasket
- Oil pan gasket
- Manifold gaskets
- Pump gasket
Cylinder Head Gasket
- The metal sandwich-type gasket is made of either copper and asbestos or steel and asbestos. It is mainly used on passenger cars and trucks.
- Embossed steel or shim type gasket is generally used on I-head engine.
- Shimbestos is a combination of thin steel heat shield on one side and a high resilient metal-reinforced asbestos on the top side.
- Felbestos is made of perforated steel sandwich between two asbestos sheets.
Oil Pan Gasket
Oil pan gaskets are made of three different materials:
- Cork has the advantage of high compressibility but it is subject to shrinkage and expansion.
- Felcoid is an improvement on the cork. It is also highly compressible but is less subject to shrinkage and expansion. It can withstand considerable bending and twisting without breakage.
- Felcoprene is a synthetic rubber compound. It is highly resilient and compressible. It is not affected by oil and greases also not subject to expansion and shrinkage.
- Metal encased asbestos gasket is more resistant to burn out but is more expensive.
- Felbestos is a perforated steel base with asbestos, mechanically bonded to one or both sides.
- Metal embossed shim gasket is also a good type of gasket for the manifolds.
Pump gaskets are made of a number of materials such as asbestos, karropak, felcoids, and more. They are treated to withstand oil, water, petrol and anti-freeze liquids. Karropak is a high-quality vegetable fibre. While Felcoid is a combination of fibre and cork granules that is more compressible and resilient.
Gaskets Coating Materials
Often the gaskets are coated with a special varnish which melts and seals all the small interstices of the block and head when the engine warms up. Some of the coating material are as follows.
- Single steel ridged or corrugated gasket
- Stainless steel
Suitable holes are made in the gasket to pass the studs and for cylinder bore. Gaskets are also used to seal joints between other parts, such as between oil pan, manifolds, or water pump and the block.
That’s it, thanks for reading. If you have any question or doubts about types of gaskets ask in the comment section below. Share this article if it is worth sharing.