Head gasket

Current technology OEM and racing head gaskets are designed to be used without additional sealant, however there are cases where head gasket sealants are required or helpful. Head gaskets sealants are specifically designed for the application; due to extremely high pressure within the combustion chamber which must be contained by the combustion seal, generic fluid sealants such as silicone should not be used for head gasket sealing. Unlike RTV silicone, head gasket sealants do not cure, they remain pliable indefinitely thereby allowing the head/gasket/block interface to achieve metal-to-metal contact under the compressive load of the tightened head bolts. Metal-to-metal contact insures a proper combustion seal. Conversely, curing sealants such as RTV silicone can form a 'rubber layer' upon which the head/gasket/block interface are separated allowing combustion pressure to eventually form a leak path to the coolant system or to the outside of the engine. Differential expansion rates of bi-metal engines are also accomodated by use of proper head gasket sealants which will not shear because they do not cure.<BR>