A Consideration on Piston Second Land Pressure and Oil Consumption of Internal Combustion Engine

Piston second land pressure, combustion pressure, and oil consumption (OC) of a four-stroke gasoline engine have been measured to investigate the relationship between 2nd land pressure and OC. Test results have revealed that OC increases when, past midway in the expansion stroke, 2nd land pressure exceeds combustion pressure and, inversely OC decreases when the 2nd land pressure is below combustion pressure. Based on both theoretical analyses and experiments, this paper describes the reason for the above observation and proposes a method for reducing OC.