The overwhelming majority of rotary engines ever produced have been the two-rotor variety. This is because, quite simply, two is generally enough. Even Mazda's Le Mans winning monster, the 787B, had just 4 rotors. In 2011, there was a bit of vaporware from a firm called Rotary Supercars which promised a 2,800-horsepower 8-rotor engine. Unsurprisingly, no actual car ever showed up. But what you will see in this video is real, and it has 12 rotors.