What Is The Engine Cylinder Head Gasket For?
1. Function: To ensure the tightness between the cylinder head and the cylinder block, to prevent air leakage, oil leakage, and water leakage.
2. Meet the requirements:
(1) It must have sufficient strength under high temperature and high-pressure conditions, and it will not be easily damaged.
(2) It has a certain degree of elasticity, can compensate for the unevenness of the contact surface, and has better sealing performance.
(3) Heat resistance, high-temperature resistance, and corrosion resistance.
(4) It will not stick to the cylinder head or block and can be used repeatedly.
3. Classification:
(1) Metal asbestos gasket: Asbestos is used as the matrix, covered with copper skin or steel skin, and metal wire or metal scraping is sandwiched between the asbestos to enhance thermal conductivity and balance the temperature of the cylinder block and cylinder head. This cylinder gasket has good Elasticity and heat resistance, widely used.
(2) Metal sheet cylinder head gasket: stamped from low carbon steel or copper sheet. Generally, high-strength engines use pure metal cylinder head gaskets. In order to ensure better sealing, around the water passage hole, oil passage hole, and combustion chamber hole, Punch out a flange with a certain height, generally used 2-3 times.
(3) Metal skeleton--asbestos pad: It is made of metal mesh or punched steel plate as the skeleton, covered with asbestos and adhesive. The surface is coated with lubricants such as graphite powder, and the metal is only wrapped around the combustion chamber hole, water channel hole, and oil channel hole. This kind of cylinder head gasket has good elasticity but is easy to bond.
(4) With. In the development of new sealing materials, some engines use single-layer thin steel plates plus heat-resistant sealant or directly use heat-resistant sealant to replace the metal pad.
Generally, heat-resistant sealant or pure metal steel backing stone is used, which often requires higher surface flatness of the cylinder head and cylinder block of the engine.
4. The method and precautions for installing the cylinder head gasket:
(1) When installing a cylinder head gasket with flanging, if the material of the cylinder block and cylinder head is the same, the flanging side faces the cylinder head. If the cylinder body is made of cast iron and the cylinder head is made of aluminum alloy, the side of the flanging faces the cylinder body, and the cylinder body has higher strength and is not easy to wear and damage.
(2) If there is a letter mark on the cylinder gasket, the mark or letter will face the cylinder head.
(3) When press-fitting the cylinder head, in order to avoid serious consequences caused by uneven deformation of the cylinder head and cylinder head gasket, the cylinder head bolts should be tightened 2~3 times from the middle to both sides, and the last time should be in accordance with the manufacturer's regulations.
When disassembling, measure from both sides to the middle. Unscrew it in 2~3 times. It is strictly forbidden to disassemble and install the cylinder head in a hot state.
