单项选择题
Cracking of a diesel piston crown can result from（）
A.Excessive piston to liner clearance B.The underside of the piston crown being excessively dirty lowering the rate of heat transfer C.Faulty nozzle spray D.All of the above
单项选择题 In an auxiliary diesel engine, the reason for knurling the piston skirt is to（）
单项选择题 Which of the listed design features is found in an exhaust valve and NOT in an intake valve?（）
单项选择题 A diesel engine cylinder head can crack as a result of （）
