Rotativi

Rotativi refers to a type of rotary engine, distinct from conventional piston engines. In a rotativo engine, rotating triangular rotors, known as Wankel rotors, move eccentrically within epitrochoidal housings. This motion creates chambers that continuously expand and contract, performing the four strokes of intake, compression, combustion, and exhaust in a cyclical manner. The rotor's movement directly drives the output shaft without the need for connecting rods, crankshafts, or valves in the traditional sense.

The primary advantage of rotativo engines is their compact size and lighter weight for a given power output compared to piston engines. They also offer smoother operation due to the absence of reciprocating parts and can achieve higher rotational speeds. However, they typically have lower thermal efficiency and can face challenges with apex seal wear and emissions control. Despite these drawbacks, rotativo engines have found applications in various vehicles, aircraft, and other machinery where their unique characteristics are advantageous. The concept was pioneered by Felix Wankel in the mid-20th century.