Reasons for notched piston rings

1. The piston ring has no elasticity without a gap, and cannot fill the gap between the piston and the cylinder wall well.
2. The piston ring will expand when heated, reserve a certain gap
3. There are gaps for easy replacement

Why are the piston rings notched but not leaking?

1. When the piston ring is in a free state (that is, when it is not installed), the gap looks relatively large. After installation, the gap will be reduced; after the engine works normally, the piston ring is heated and expanded, and the gap is further reduced. I believe that the manufacturer will definitely design the size of the piston ring when it leaves the factory to make the gap as small as possible.
2. The piston rings will be staggered by 180°. When gas runs out from the first air ring, the second air ring will block the air leakage. The leakage of the first gas ring will first impact the second gas ring, and then the gas will be expelled and run out through the gap of the second gas ring.
3. There is an oil ring under the two air rings, and there is oil in the gap between the oil ring and the cylinder wall. It is difficult for a small amount of gas to escape from the gap in the oil ring into the crankcase.

Summary: 1. Although there is a gap, the gap is very small after the engine works normally. 2. It is difficult for air leakage to pass through three piston rings (divided into gas ring and oil ring).