The three rings of a piston ring are mainly divided into two types: the oil ring at the piston pin hole and the other two rings are compression rings. The compression ring, also known as the top ring, is primarily used to seal the piston, prevent gas leakage from the cylinder, and transfer the heat from the top of the piston to the cylinder liner, which is then dissipated by cooling water. The other type is the oil ring, which can store some engine oil itself, used to lubricate the cylinder liner, and can also scrape off excess engine oil from the cylinder liner.
Why are the piston rings, one compression ring white and one black?
The color difference of piston rings, mainly depends on the material of the compression ring. The white compression ring surface is generally coated with a layer of metal chromium, while the black compression ring is cast iron, so it appears darker in color. Normally, the first compression ring of the piston is white. The white compression ring is barrel-shaped and can fit closely with the cylinder liner regardless of the working state of the piston.
The second compression ring is a black compression ring, which is rectangular in shape. It is not placed in the position of the first compression ring mainly because the swinging motion of the rectangular ring may scrape against the inner wall of the cylinder, leading to poor sealing.
How to maintain piston rings?
1：Add high-quality engine oil to the vehicle. When the engine is operating normally, the piston rings will move vigorously with the piston. High-quality engine oil has better lubricating effects, which can reduce its wear to a certain extent.
2：Regularly clean foreign objects in the cylinder. Excessive substances such as oil stains and carbon deposits can affect the normal operation of the piston rings and accelerate the wear of the cylinder liner, which may even cause cylinder pulling.
3：Ensure proper installation of piston rings. If the piston rings do not match the cylinder liner, it may easily lead to deformation.
