1977 Mazda Inside the Rotary Engine Sales Folder. Birth of a notion. Like many great ideas, the principle of the rotary engine is simple. Vive Le Diffrerence. What makes the rotary engine different from a conventional reciprocating engine? Many things. Instead of pistons moving up and down, the rotary engine employs whirling rotors. All 'round efficiency. The rotary engine is an efficient powerplant, by virtue of its design. The Mazda Rotary - Inside and Out. Open it up to find out more about: The perfect combination. Why it's more compact. Why it's quieter. How it prevents air pollution. Proved on the race track; winner of awards. It's a rotary world.