In a complete four-stroke cycle, how many crankshaft degrees are required to complete all four strokes?

In a complete four-stroke cycle, how many crankshaft degrees are required to complete all four strokes?

• A. 360
• B. 720
• C. 540
• D. 180

Answer: (B)

A complete four-stroke cycle requires two full crankshaft revolutions. Each stroke—intake, compression, power, and exhaust—takes 180 degrees of crankshaft rotation, so four strokes add up to 4 × 180 = 720 degrees. That means the entire cycle spans 720 crankshaft degrees, or two turns of the crank. The other options correspond to only partial rotation: 360 degrees is one full turn, not enough for all four strokes; 180 degrees is just one stroke; 540 degrees is 1.5 turns, still not the full cycle.

A complete four-stroke cycle requires two full crankshaft revolutions. Each stroke—intake, compression, power, and exhaust—takes 180 degrees of crankshaft rotation, so four strokes add up to 4 × 180 = 720 degrees. That means the entire cycle spans 720 crankshaft degrees, or two turns of the crank. The other options correspond to only partial rotation: 360 degrees is one full turn, not enough for all four strokes; 180 degrees is just one stroke; 540 degrees is 1.5 turns, still not the full cycle.