The cylinder head is generally made of gray cast iron or alloy cast iron, but in order to improve the fuel economy of the vehicle, the weight of the engine is imminent, and the use of light materials can effectively reduce the quality of the engine. Light engines (gasoline engines and diesel engines with a displacement of less than 3L) widely use alloy materials for cylinder heads. Under the same structure, compared with cast iron materials, the mass can be reduced by 40% to 60%.

Aluminum alloy has good thermal conductivity, good cooling performance, and is an excellent cylinder material. The addition of Cu to the aluminum alloy can improve the thermal stability, and the addition of Mg can increase the hardness of the casting.

The cylinder head is installed on the cylinder block to seal the cylinder from above and form the combustion chamber. It is often in contact with high-temperature and high-pressure gas, so it bears a large thermal load and mechanical load. A cooling water jacket is made inside the cylinder head of a water-cooled engine, and the cooling water hole on the lower end of the cylinder head communicates with the cooling water hole of the cylinder block. Use circulating water to cool high temperature parts such as combustion chamber.

The cylinder head is also equipped with intake and exhaust valve seats, valve guide holes for installing intake and exhaust valves, as well as intake and exhaust channels. The cylinder head of the gasoline engine is machined with holes for installing spark plugs, while the cylinder head of the diesel engine is machined with holes for installing fuel injectors. The cylinder head of the overhead camshaft engine is also machined with a camshaft bearing hole for installing the camshaft.