USCG Exam PracticeDiesel engine principles (motor propulsion)
In a four-stroke diesel engine, what is the correct sequence of piston strokes beginning with the intake stroke?
- ✓ Intake, compression, power, exhaustCorrect
- B. Intake, power, compression, exhaust
- C. Compression, intake, power, exhaust
- D. Intake, compression, exhaust, power
Why A is correct
The four-stroke cycle proceeds: intake (piston down, intake valve open), compression (both valves closed, piston rises), power (fuel injected, gases expand, piston driven down), exhaust (exhaust valve open, piston rises and expels spent gas). The complete cycle requires two crankshaft revolutions.
Cited:DOE-HDBK-1018 Vol.1 §1-1