Modern automobile engine body group is mainly composed of body, cylinder head, cylinder head cover, cylinder liner, main bearing cover and oil pan. The body group is the support of the engine, and it is the assembly base of the crank connecting rod mechanism, the valve mechanism and the main parts of the engine system. The cylinder head is used to seal the top of the cylinder and, together with the piston top and cylinder wall, forms the combustion chamber.The cylinder head is used to seal the cylinder and form the combustion chamber. The cylinder head is cast with water jacket, water inlet hole, water outlet hole, spark plug hole, bolt hole, combustion chamber, etc.