The cylinder head is used to seal the upper part of the engine and forms a combustion chamber with the cylinder block. A water channel is connected to the cylinder block to cool the engine. The valve assembly and spark plugs are installed on the cylinder head.

The cylinder liner of the cylindrical piston diesel engine bears the thrust of the piston side and becomes the lead of the reciprocating movement of the piston. Transfer the heat of the piston assembly and itself to the cooling water to make it work at a proper temperature.

The cylinder liner is a cylindrical part, which is placed in the cylinder body hole of the machine body, and the upper part is pressed and fixed by the cylinder head. The piston reciprocates in its inner hole and is cooled by cooling water outside.