Lighter and More Robust Piston Ring for High Performance Engines

The piston is one of the most important parts of an IC engine. With improving technology and growing research, the design and function of piston have taken a breakthrough toll. Other than transferring energy to its connecting rod, piston performs several other functions such as aiding better atomization, swirling the fuel mixture, etc.

It's one of the reasons these days, we hardly see flat top pistons in the engine. One can find intricate designs of piston crowns as they can perform several other functionalities. They also help in reducing the emission and aid better combustion. Due to intensive studies in the field of computational fluid dynamics and computer-aided engineering, such design of the piston has come into existence. Each piston has grooves cuts over which piston rings reside. With growing improvement in piston designs, the number of piston ring required has been reduced. Mostly piston uses only three kinds of rings, namely, compression ring, second ring and oil ring, each of which has a specific function to perform. The compression ring is the top most ring which helps in sealing of the combustion chamber and thus preventing any leakage of air or gases out from the chamber.

Below the compression ring lies the second ring which seals the combustion ring and limits the supply of oil into the cylinder liner used to lubricate the piston and compression ring. Oil ring is used to scrape off the excessive oil from the cylinder liners. Although piston rings are capable of preventing the loss of air or gases from the combustion chamber, there is certainly a possibility of some amount of air or gases to escape due to the movement of piston ring which creates a gap within its grooves. To prevent any blow by caused due to the movement of the piston ring, mostly the gaps are kept at 120 degrees apart during installation.

Cylinder sleeve is widely known as cylinder liner. It is a cylindrical lump that fits over the engine to form a cylinder. They are known to provide three main functions:

1. It helps in forming the sliding surface for the piston of the engine.
2. It provides heat transfer from the piston and piston rings to the coolant.
3. It acts as sealing and prevents air or gases from escaping out of the combustion chamber.

As cylinder sleeves are exposed a lot towards robust working conditions, they get to easily wear out with time and hinders the overall performance of the engine. Thus, it is highly essential that their proper maintenance and routine checks from time to time. The cylinder liner mainly wears out for one of the four reasons:

1. Friction
2. Corrosion
3. Abrasion
4. Adhesion

When two surfaces glide over each other, friction is produced and due to which wearing takes place. Corrosion happens due to the burning of oil in between the free spaces of the engine or due to reduced service load causing a drop in the temperature of the combustion chamber. Abrasion happens due to the presence of hard particles in the fuel, metal swarf, ash formed during combustion, etc. Whatever may be the case, it's important to perform regular checks for the engine to be able to deliver high-performance results.