1. The cylinder head bolts and nuts are elongated or loose.
Due to the extrusion deformation of the cylinder head and the engine body joint surface, the compression deformation of the cylinder head gasket, the accidental overload caused by the pressure of the high pressure gas on the cylinder head bolts and nuts, the cylinder head bolt screwing depth is insufficient, and the microscopic unevenness of the thread surface is pressed. Flatness and the necking of the bolt due to excessive torque can cause the cylinder head bolt nut to be elongated or loose, which results in insufficient pressure on the joint surface of the cylinder head and the engine body and uneven pressure everywhere, resulting in high temperature and high pressure gas from the local The part with less pressure is thrown out and the cylinder head gasket is burned out.
2. The cylinder head and the engine body joint surface are deformed.
If the two joint faces are deformed, the cylinder head gasket cannot be uniformly pressed, and thus the air leakage causes the cylinder head gasket to burn out, which is also the main cause of the cylinder head gasket burning.
3, the installation does not match.
During installation, the cylinder head joint surface is not clean, the order of the cylinder head bolts and nuts is not correct, the torque is not large or uneven, and the upper end surface of each cylinder sleeve is not high enough or not equal to the upper plane of the engine body, causing air leakage and burning. Cylinder head gasket.
4, the engine is overheated.
The engine cooling system is not working properly, the oil supply time is too late, and the long-term overload operation will cause the engine to overheat, especially in the part between the intake and exhaust valve seat of the cylinder head and the outlet of the vortex chamber passage, due to the high temperature. The role of the cylinder head gasket lost its original elasticity and became brittle, and finally burned.
5, the quality of the cylinder head itself is unqualified.
If the thickness is uneven, the roll is not flat, the elasticity is insufficient, the material is not good, the surface is not flat, etc., or the cylinder head gasket is not damaged during disassembly and assembly, and the cylinder head gasket is easily burnt.