Rotary engines made their largest have an effect on in Mazda sports activities automobiles, however a up to date episode of “Jay Leno’s Storage” delves into the rotary’s previous historical past.

Earlier than it was once popularized through Mazda, the rotary engine entered manufacturing with German automaker NSU (an Audi predecessor). The NSU Spider introduced in 1964—3 years prior to Mazda introduced its first rotary automotive, the Cosmo 110S. A kind of early NSU rotary automobiles is now a part of Jay Leno’s assortment.

The rotary engine was once invented through German engineer Felix Wankel after which approved to automakers. It will get its identify from the truth that, as an alternative of pushing pistons, the power from the combustion of gas and oxygen is used to spin a rotor (or every now and then two, as was once the case with later Mazda engines).

The rotor has a triangular form however is fastened in a kind of spherical housing. The corners of the triangle are designed to seal towards the housing (one thing that proved difficult for engineers to succeed in) permitting open areas at the aspects to function the combustion chamber. The fuel-air combination (ignited through only one spark plug within the NSU) pushes towards the edges of the rotor, spinning it.

Some great benefits of rotary engines have been clean operation and compact measurement. The NSU Spider’s engine is so small that it sits under the rear baggage compartment, giving this convertible each a traditional trunk and a frunk that help in making up for its small measurement. The air consumption is positioned at the rear trunk lid; air is directed down into the engine thru a pipe within the trunk.

Disadvantages integrated upper oil intake than typical piston engines, and a self-destructive eagerness to rev. The NSU can simply rev to eight,000 rpm, Leno notes within the video, however that can put on out the rotor’s seals. The tachometer even has a inexperienced zone finishing at about 5,500 rpm to inspire extra conservative riding habits.

The NSU Spider was once additionally reasonably dear for its time. It value round $3,500 in 1964, greater than different small sports activities automobiles just like the MGB. And it best had 54 hp, despatched to the rear wheels thru a 4-speed guide transmission. Even with the Spider’s kind of 1,500-lb curb weight, that made for a riding revel in that required a little bit of endurance.

Rotary engine

After construction a rotary sedan known as the R080, NSU was once got through the Volkswagen Team within the overdue Sixties and folded into what changed into Audi.

Rotary engines lived on, with Common Motors and Mercedes-Benz experimenting with them within the Seventies and Mazda making them an ordinary function in its lineup, particularly within the RX-7 and RX-8 sports activities automobiles. The rotary-powered Mazda 787B changed into the primary Jap automotive to win the 24 Hours of Le Mans in 1991, however Mazda rotary manufacturing sooner or later led to 2012.

Mazda introduced the go back of the rotary engine early this 12 months, albeit as a variety extender in a brand new R-EV model of the MX-30 electrical crossover. The MX-30 R-EV would possibly not be coming to the U.S., however Mazda unveiled an electrified rotary idea known as the Iconic SP on the 2023 Tokyo auto display. That are supposed to stay hopes for the go back of the rotary sports activities automotive alive.