1, cover and seal the cylinder head, keep the oil inside, while the dirt and moisture pollutants isolated from the outside; 2, the oil and air isolation;
3, act as an oil filling port; 4, can be used as sensor mounting support, including camshaft position and camshaft timing sensors.
Cylinder head is mainly sealed cylinder, with the piston together to form a combustion space,
and withstand the role of high temperature and high pressure gas.