Analysis of Piston Ring Sealing Performance in Ring Groove on Piston

From some studies of oil consumption in internal combustion engines, gas flow within the cylinder is known to be closely related to oil consumption. Because oil condition on piston lands is also supposed to be affected by gas flow, visualized observation through in-cylinder is an effective measure to clarify mechanism of oil consumption. So far some observations on lands and skirt of piston have been made. This paper first presents calculation of piston ring movement at each engine stroke to predict piston ring movement as the cause of the increase of oil consumption at medium speed and light load, followed by observation at each engine stroke to inspect this prediction. Because second ring collapse was observed when using a top ring with different specification, the relationship between the gas sealing ability of the top rings and second ring collapse is also presented.