A Study on Lubricating Oil Flow into the Combustion Chamber for the Top Ring with a Special Joint

The authors have utilized a modified engine with a transparent glass cylinder for motoring equipment. The effect of the top ring which has a special joint (triangle step joint) on the lubricating oil flow was examined.

The results indicate that the lubricating oil flow is considerably reduced by utilizing the top ring with a special joint (triangle step joint) as compared to a standard joint (straight joint). We have also found that if the modified engine is operated with attention to the pressure difference between intake manifold and crankcase, or the positions of the piston ring gaps, the lubricating oil flow is reduced by utilizing a two piston ring set (where a top ring and an oil ring are set on a piston) with the top ring having a special joint and without the second ring as compared to a three piston ring set (where a top ring, a second ring and an oil ring are set on a piston) with the top ring having a standard joint and with the second ring.