Reduction of Engine Oil Consumption and Durability Improvement of Four Stroke Forced Air Cooled SI Engine

Engine oil consumption constitutes a significant share of the operating costs for a commercial vehicle and increases the HC emissions. This paper presents an experimental study of various measures to reduce engine oil consumption for a four stroke, single cylinder spark ignition engine as a part of development of a light commercial passenger carrier. By studying the piston geometry, ring pack, cylinder bore distortion, cylinder block, piston and ring heat transfer, the following parts were redesigned to reduce the engine oil consumption - piston geometry, cylinder block fin, oil jet for piston under crown, cooling fan profile and breather circuit. With the new design configuration the oil consumption under highway endurance conditions reduced by 30% while that under city endurance reduced by as high as 50%. The resultant design modifications also improved the durability of cylinder block and piston parts by 70%.