Every car that's won the 24 Hours of Le Mans has had a conventional piston engine—except one. That's the Mazda 787B, which won the legendary French endurance race in 1991, after 17 years of trying.
As detailed in this Mazda-produced video, the 787B was powered by a rotary engine, similar to what was still being used in the Mazda RX-7 sports car at the time. But while the RX-7's two-rotor 13B engine never produced more than 200 hp in stock form, the race car's four-rotor R26B engine was estimated to produce close to 700 hp at 9,000 rpm.
Designed for FIA Group C—the top category in sports-car racing at the time—the 787B also sounded unlike any other modern race car. When Turn 10 Studios added the 787B to "Forza Motorsport 4" in 2012, it was the loudest car ever recorded for the video-game series.
1991 Mazda 787B four-rotor race car
Mazda entered three cars at Le Mans in 1991, including one 787 and two of the improved "B" versions. All three started far back in the field, but the number 55 car driven by Volker Weidler, Johnny Herbert, and Bertrand Gachot scored victory. The other two cars finished sixth and eighth.
After 1991, rule changes made the rotary engine uncompetitive, and the 787B became a museum piece. Aside from the occasional demonstration run, the winning car has remained sequestered in Mazda's company museum in Hiroshima, Japan. Mazda would remain the only Japanese manufacturer to win Le Mans until Toyota's first victory in 2018.
Mazda eventually returned to sports-car racing, but this time in the U.S. with the IMSA sanctioning body. Still trying to keep its race cars relevant to its road cars, Mazda initially used diesel engines, and then small turbocharged gasoline engines. Those engines all had pistons, but the rotary engine is set to make a return—as a range extender for the MX-30 electric crossover.