The cylinder head is machined with exhaust valve seat holes, valve guide holes, spark plug mounting holes, and fuel injector mounting holes. In the cylinder head, there are also cast water jackets, intake and exhaust ducts, and combustion chambers or parts of combustion chambers. The function of the cylinder head is to close the upper part of the cylinder and form a combustion chamber together with the top of the piston and the cylinder wall.

What is the composition and function of the cylinder head

The cylinder head belongs to the valve mechanism in the internal combustion engine. It is mainly used to close the upper part of the cylinder to form the combustion chamber, as well as the camshaft and rocker shaft as well as the intake and exhaust pipes. The main purpose is to suck air into the cylinder, the spark plug ignites the combustible mixture, and drives the piston to do work, and the exhaust gas is discharged from the exhaust pipe.

Cylinder heads are generally made of high-quality gray cast iron or alloy cast iron, while gasoline engines used in cars mostly use aluminum alloy cylinder heads. Aluminum alloy has good thermal conductivity, which is beneficial to improve the compression ratio of the engine. Secondly, it has excellent casting performance and is suitable for casting parts with complex structures. However, attention must be paid to the cooling of the aluminum alloy cylinder head, and the temperature of its bottom surface should be controlled below 300 degrees Celsius, otherwise, the bottom surface will be overheated and plastic deformation and warping will occur.