① The selection of piston shall be determined according to the repair size of the cylinder. Generally, the increased size value shall be marked on the piston crown;

② In the same series of fish feeding clusters, the piston structure is not necessarily the same, so when selecting pistons, the corresponding type of piston must be selected according to the type of engine On the same engine, pistons of the same brand, group or product code shall be used; Pistons with the same product code must be used for the same model to ensure that the piston diameter difference and quality difference do not exceed the range specified by the original manufacturer. Otherwise, the engine will suffer from poor combustion, rough operation, reduced economy and power performance. Therefore, when selecting pistons, the corresponding type of piston must be selected according to the type of engine.

As the piston of internal combustion engine works under the conditions of high temperature, high pressure and high load, the requirements for the piston are relatively high, so the classification of internal combustion engine piston is mainly discussed.

1. According to the fuel used, it can be divided into gasoline engine piston, diesel engine piston and natural gas piston.

2. According to the material of piston, it can be divided into cast iron piston, steel piston, aluminum alloy piston and combined piston.

3. It can be divided into gravity casting piston, squeeze casting piston and forging piston according to the process of manufacturing piston blanks.

4. According to the working conditions of pistons, they can be divided into non pressurized pistons and pressurized pistons.

5. According to the use of pistons, they can be divided into car pistons, truck pistons, motorcycle pistons, marine pistons, tank pistons, tractor pistons, lawn mower pistons, etc.