An engine and a method of making same

摘要

An internal combustion engine 10 is provided with cylinders 19 having a predetermined surface finish thereon comprising of at least two differing patterns. The first pattern is designed to provide a predetermined storage volume for oil used to lubricate a piston 22 which is slidingly engaged in the cylinder 19. The second pattern is different to the first pattern in that it provides little or no storage capacity for the oil. The second pattern is applied to the wall 28 of each cylinder 19 at one or more positions where impingement of unburned fuel against the cylinder wall 28 is to be expected. The reduced storage volume of the second pattern reduces the volume of unburned fuel that can be transferred from the cylinder 19 to the oil supply of the engine 10.