Free FAA A&P Powerplant Flashcards

A four-stroke cycle needs intake, compression, power and exhaust strokes, and because the crankshaft makes two full revolutions (720 degrees) to complete them, each cylinder fires only once per two revolutions. The other three strokes are carried by the momentum of the crankshaft and propeller and by the overlapping power strokes of the other cylinders, which is why the propeller still turns smoothly.