1. Cylinder liner Cylinder barrel: It is inlaid in the cylinder barrel of the cylinder block, and forms the combustion chamber together with the piston and the cylinder head;
2. Piston: It is a reciprocating part in the cylinder block of an automobile engine;
3. Piston ring: It is a metal ring used to embed in the piston groove, and is used to scrape off excess oil on the cylinder.
4. Piston pin: It is a cylindrical pin installed on the skirt of the piston, which is used to transmit the gas force borne by the piston to the connecting rod, or to make the small end of the connecting rod drive the piston to move together.

1. Definition and classification of engine: An engine is a machine that converts other forms of energy into mechanical energy. The current engines are divided into internal combustion engines, external combustion engines, jet engines and electric motors.
2. The birthplace of the engine: The engine is an important part of the vehicle, and the earliest engine was born in the UK.
3. The method of distinguishing the engine: The parameter for distinguishing the engine is the engine displacement. The larger the displacement, the stronger the power output of the engine, and the stronger the power.