A Relationship between Cylinder Bore Deformation and Lubricating Oil Consumption on Conventional Gasoline Engine in Engine Operation

Abstract

This study was aimed at clarifying the relationship between cylinder bore deformation and lubricating oil consumption(LOC), using a conventional in-line four-cylinder gasoline engine. The rotary piston method developed by the author et al. was used to measure the cylinder bore deformaition of the engine. In addition, the sulfur tracer method was applied to measure LOC of each cylinder. We then made a calculation of piston ring oil film thickness, using a model to predict a ring's conformability considered cylinder bore deformetion. The results were used to calculate the rate of oil flow into a combustion chember, and the rate of oil evaporation from a cylinder wall. As a result of the measurements and the calculations, we consider it necessary to improve cylinder deformation at the cylinder's upper part, and ring's conformatiblity performance to a cylinder for the purpose of controlling increase in LOC.