In order to establish a new temperature criterion to prevent the pistons from ring sticking due to deposit formation, bench test and engine test were performed. Bench test results show that oil oxidation is more effective to the deposit formation than...
In order to establish a new temperature criterion to prevent the pistons from ring sticking due to deposit formation, bench test and engine test were performed. Bench test results show that oil oxidation is more effective to the deposit formation than oil nitration. The temperature increase accelerates deposit formation and deposit formation increase rapidly above 260℃. Especially, in case of degraded oil, the deposit formation increases so rapidly that ring sticking can occur. The effect of piston temperature on the deposit formation was confirmed by engine test.<br/>