The crankcases of many diesel engines are kept under a slight vacuum to （）
举一反三
- According to the fuel an engine burns, there are ________. A: reciprocating and rotary engines B: gasoline and diesel engines C: 4-cylinder and 6-cylinder engines D: inline and boxer engines
- Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the （）.
- Diesel engines are started by supplying （） into the cylinders in the appropriate sequence for the required direction.
- In diesel engines， the four basic events (intake， compression， power and exhaust) are performed once in （）.
- The principal difference between loop scavenging and crossflow scavenging， as used in single acting diesel engines， is the （）