How to choose good engine piston

How to choose good engine piston

The engine is like the "heart" of the car, and the good Engine Piston can be understood as the "center" of the engine. In addition to the poor working environment, it is still one of the busiest engines, constantly moving from the bottom dead center to the top. Dead Angle, from the top to the bottom of the reciprocating motion, inspiration, compression, work, exhaust... The inside of the piston is designed to be hollow, more like a hat, with the two ends of the hole connected to the Piston Pin, which connects to the small end of the connecting rod, and the large end of the connecting rod to the crankshaft, converting the reciprocating motion of the piston into a circular motion of the crankshaft.

There are three pleats in the skirt of each piston, and two air rings and an oil ring are installed with the air ring on top. When assembling, the openings of the two air rings need to be staggered to act as a seal. The function of the oil ring is mainly to scrape off the excess oil splashed on the cylinder wall, so that the oil is evenly spread. At present, the widely used Piston Ring materials are high quality gray cast iron, ductile cast iron, alloy cast iron and so on.

In addition, the position of the piston ring is different, the surface treatment is also different. The outer surface of the first piston ring is usually plated with chrome or sprayed with molybdenum, mainly to improve lubrication and increase the wear resistance of the piston ring. Most other piston rings are tinned or phosphating, mainly to improve wear resistance.

Because the working environment of the piston in each cylinder is slightly different, the degree of carbon accumulation of the piston is also different
If the piston ring is improperly installed or sealed, it will cause the oil on the cylinder wall to crush into the combustion chamber and mix with the air-fuel mixture, causing the fuel to burn. If the clearance between the piston ring and the cylinder wall is too small or the piston ring is stuck in the ring groove because of carbon deposition, the piston may scratch the cylinder wall when reciprocating up and down, and stay in the cylinder for a long time. The formation of deep grooves in the wall is often called "pulling drum". Cylinder wall groove, poor sealing, will also cause oil burning. Therefore, the working state of the piston should be checked regularly to avoid the occurrence of the above two situations and ensure that the engine is in good condition.