Piston Rings

Sun (Auckland), Volume I, Issue 248, 10 January 1928, Page 7

Piston Rings

Question of Leakage How to Prevent it On taking down an engine and examining the pistons, it is sometimes found that the piston-rings, instead of being in their position as when originally fitted, with the gaps equally spaced around the pistons, have worked round until the gaps meet and form a break from the top ring to the bottom, thus forming a direct path for the gases, this causing poor compression and back pressure in the crank-case, with all the inconveniences which result from these, such as bad starting, poor acceleration, and oily plugs. The explosion in the combustion chamber forces a small amount of gas through the gap of the first' ring, and, this being at an angle, pressure to one side results, and the ring gradually works round in its groove. Tf/however. the lower ring is so fitted that its slot is set at a different angle from the ring above it, then one ring tends to move to the left and the other to the right, so that if, in the course of time, the gaps of any two piston rings are ever in line, so that a gas passage is formed, they will remain so for a very short period only, and the slots will gradunllv move away from each other.