单项选择题
If clearance between a piston and the cylinder wall is excessive, piston slap will occurThe slap itself is caused by （）
A.alternation of side thrust B.a breakdown of the lube oil film on the cylinder wall C.worn piston boss piston pin bearings D.fluctuating gas pressure in the combustion space
单项选择题 Poor quality fuel being used in a turbocharged medium-speed, diesel engine could result in （）
单项选择题 Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to （）
单项选择题 Cracking of a diesel piston crown can result from（）
