The mechanism of the engine lubricating oil consumption is very complex, and there are many factors which influence the oil consumption. To devise a way to reduce the oil consumption, the authors tentatively develped a computer program for predicting the oil consumption. For that purpose, a simple mathematical model simulating a phenomenon involving oil rising from the piston skirt to the top land by way of the piston rings and oil disapperaing from the top land was developed.
In this model, the authors treated the combination of the piston rings as a pack. This made it possible to evaluate the influences of such factors as, the piston ring surface profile, the land clearance above the oil ring, the piston skirt clearance, the ring load pressure, etc..