What is the common name for an engine that completes a cycle in two strokes?

What is the common name for an engine that completes a cycle in two strokes? The answer is two-stroke engine. In this design, the piston completes a power cycle with one upward stroke and one downward stroke, while the crankshaft makes one revolution. Intake, compression, combustion and exhaust still occur, but several processes overlap rather than receiving a separate stroke.

A typical crankcase-scavenged two-stroke compresses the fresh charge below the piston during its upward movement. Near the top, the charge in the cylinder is compressed and ignited. As the piston moves down, expanding gases produce power, while ports open to begin exhausting burned gases and transferring fresh charge into the cylinder.

Two-stroke engines can produce a high power-to-weight ratio and use fewer moving parts than many four-stroke engines. They became common in motorcycles, mopeds, chainsaws and other portable equipment. Their traditional oil-fuel lubrication and overlapping gas exchange can increase emissions, which is why emissions rules pushed many road vehicles toward four-stroke designs.