Influence of piston-bore clearance on second motion characteristics of piston and skirt wear

The piston dynamic simulation was carried out for the wear of the piston skirt after the test of gasoline engine. In addition, the second motion and wear are studied for the improvement proposal of different cylinder clearances. Results show when the original cylinder clearance is 0.0325 0.0575 mm, the minimum operating clearance of the piston skirt is smaller; it is not good for the formation of lubrication oil film, which causes wear on the thrust side and anti-thrust side of piston skirt. When the cylinder clearance was increased to 0.0400 0.0650 mm, the wear load on the thrust side and anti-thrust side of piston skirt was reduced by 68.3% and 68.1%, respectively, the effect of improved wear is better and the result coincides well with engine test result.