Jay Leno Breaks Down the Mazda Rotary Engine

Mazda sports cars are renowned for their rotary engines, but the early history of this engine design is often overlooked. A recent episode of “Jay Leno’s Garage” aims to change that by showcasing a rotary engine that was used in a German automaker’s car long before Mazda popularized it. The car in question is the NSU Spider, which was produced by NSU, a predecessor of Audi, in 1964. Interestingly, this was three years before Mazda launched its first rotary car, the Cosmo 110S. It’s worth noting that one of the early NSU rotary cars is now part of Jay Leno’s impressive collection.

German engineer Felix Wankel is credited with inventing the rotary engine. The engine was then licensed to various automakers. The rotary engine gets its name from the fact that it uses energy from the combustion of fuel and oxygen to spin a rotor, unlike traditional engines that use pistons. The rotor is usually triangular in shape, although later Mazda engines used two rotors. The rotor is mounted in a roughly round housing, with the corners of the triangle designed to seal against the housing. Achieving this seal was a challenge for engineers. The open spaces on the sides of the rotor serve as the combustion chamber, with the fuel-air mixture being ignited by just one spark plug in the case of the NSU. The resulting explosion pushes against the sides of the rotor, causing it to spin.

The rotary engine had several advantages over traditional engines, including smooth operation and a compact size. The NSU Spider’s engine is so small that it sits below the rear luggage compartment, which allowed the car to have both a conventional trunk and a front trunk, compensating for its small size. The air intake for the engine is located on the rear trunk lid, and air is directed down into the engine through a pipe in the trunk. This unique design allowed the NSU Spider to be one of the few sports cars of its time that could offer both practicality and performance.

After producing a rotary sedan called the R080, NSU was acquired by the Volkswagen Group in the late 1960s and integrated into what would later become Audi.

Even after the acquisition, rotary engines continued to be developed. General Motors and Mercedes-Benz experimented with rotary engines in the 1970s, while Mazda made them a staple of its lineup, especially in its RX-7 and RX-8 sports cars. In 1991, the Mazda 787B, which was powered by a rotary engine, became the first Japanese car to win the 24 Hours of Le Mans. However, Mazda stopped producing rotary engines in 2012.

Earlier this year, Mazda announced that it would be bringing back the rotary engine as a range extender in a new version of its MX-30 electric crossover, called the R-EV. Although the MX-30 R-EV will not be available in the U.S., Mazda unveiled an electrified rotary concept called the Iconic SP at the 2023 Tokyo auto show. This move has sparked hope that the rotary engine will once again be used in sports cars in the future.

Photo Source: Mazda Newsroom