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, compression, power, exhaust over two crankshaft revolutions. During intake the piston descends with the intake valve open; during compression both valves close and the piston rises; fuel is injected and ignites at the power stroke; the exhaust valve opens for the final stroke.
Cited:DOE-HDBK-1018 Vol.1 §1-1