Observation of Lubricating Oil Flow from the Sump to the Combustion Chamber through the Piston Ring Belt in an Automobile Gasoline Engine.

Abstract

The behavior of lubricating oil flow from the sump to the combustion chamber through a clearance between piston and cylinder was observed in this study using an experimental automobile gasoline engine equipped with a transparent glass cylinder. The effect of pressure difference between intake manifold and crankcase, oil temperature and oil ring tension on oil flow through the piston ring belt were studied in this program. We have also found that the oil injected from the large end of the connecting rod flows from the inside of the piston through the oil ring drain back slots into the oil ring groove. The drain back slots which should lead the oil in the groove to the inside of the piston, act now therefore in the reverse way.