Ring gap is very critical part of engine, responsible for its longevity and performance and is a number-one tech question which is asked very frequently by automobile drivers. In this article, it would explain why rings in piston need a gap, how to do it, and some very frequently made ring-gapping mistakes.
As rings of piston need to be broadened to fit over the diameter of the cylinder liner itself before they find their position in the ring grooves. The pin has to be split in some way in order to allow installation. It also needs to be kept in mind that the gap between the ends of the ring needs to be kept as narrow as possible, for a number of reasons. The main purpose of the ring is to hold the liner in compression and pass heat from the cylinder to the ring. From this being done, energy is redirected from the cylinder with the use of water in the water jackets.
Keeping these facts in mind diesel engine experts point that the piston pin tackles the most amount of heat. This fact is also very important because it is very obvious that the smaller the gap, the fewer chances there are for the pressure of the combustion chamber to make its way past the first ring. But the ring must have more contact with the ring as well as the cylinder wall in order to transfer heat.
The gap that the manufactures create in the top ring is to make the ring go hand-in-hand with the maximum expansion that the manufacturers think that the top ring might require. This is very important to understand that as the top ring is held accountable for holding in compression there is a very thin line of making sure that piston ring is not getting overloaded with compression, but not expanding so much so that they collide into each other.
Summary
The pathway to ensure proper pin gap is to make sure there is room for expansion. As the diesel engine functions ring to heat up, without creating unwanted blow-by and excessive clearance.
