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Why can a two-stroke engine produce more power strokes than a four-stroke engine of the same size?

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Labeled cross-sectional diagram of a V-type gasoline engine for an automobile, showing internal components such as pistons, crankshaft, camshaft, intake and exhaust valves, connecting rods, spark plugs, and intake manifold. — gasoline engine Cross section of a V-type engine.

A two-stroke engine produces more power strokes than a four-stroke engine of the same size because it completes its entire working cycle in only two strokes of the piston and one revolution of the crankshaft, whereas the four-stroke cycle requires four strokes and two revolutions to complete the same process.123

In a four-stroke engine, the piston must perform separate intake, compression, power, and exhaust strokes. By contrast, the two-stroke engine eliminates the dedicated intake and exhaust strokes, combining the functions of scavenging and charging into the compression and power strokes. Because the power stroke occurs once every revolution in a two-stroke engine—compared to once every two revolutions in a four-stroke engine—the two-stroke design can generate more power from an engine of a given size at a specific operating speed.312

However, this increased power density comes with trade-offs, including lower fuel economy and higher emissions, as the simplified scavenging process can lead to a loss of fresh fuel mixture through the exhaust ports.3