单项选择题
A.scavenging air ports;exhaust ports
B.inlet ports;scavenging air ports
C.scavenging air ports;inlet ports
D.exhaust ports;inlet ports
单项选择题 If the engine is naturally aspirated, or is a small high-speed type with a centrifugal turbocharger, the period of valve overlap(),ie when both valves are(), will be and the exhaust valve will close some 10°top dead canter().
单项选择题 ()is the main reason that reduces the power advantage of a two-stroke engine over a same size four-stroke one to about()
单项选择题 In a diesel engine, when the fuel is injected into the cylinder,()