Study of Oil Flow Surrounding Piston Rings and Visualization Observation

By observation through a glass window, the effect of side surface sealing ability of piston ring on the increase of oil consumption for light load and at medium engine speed range was confirmed. In each engine stroke, effects of ring motion on oil consumption were predicted by simulation and the flow of oil around piston ring was observed during actual firing engine operation through a visualization window with a test engine. Importance of the side surface sealing ability of piston ring on oil consumption and effect of small width top ring with positive twist for second ring collapse were reconfirmed.