Even though it looked quite promising when it was being developed, the rotary engine did not achieve widespread usage. Rotary engines (also called Wankel engines)are famed for their smoothness, but they are fuel-thirsty and do not have the higher torque of piston engines. Despite all these failings, the technology has earned a cult following because of Mazda and its assortment of rotary sport car models. Today commemorates fifty years from the time that the Cosmo Sport 110S was unveiled in Tokyo and in the process kick-started a romantic affair with the rotary engine.
The rotary engine design was conceived by Felix Wankel, an engineer, and notorious Nazi, who considered it to be a viable method of delivering outstanding power and smoothness from a tiny package. Basically, a Wankel engine comprises of only two moving parts – an eccentric shaft(which functions like the piston engine’s crankshaft) and a triangular-shaped rotor. The process of combustion turns the rotor round in its elliptical casing to drive the main shaft. The end result is a smooth-running, valveless and compact engine – but one that is also thirsty and wears down reasonably fast.
Mazda, by then called Toyo Kogyo Corporation, was well-known for its micro cars and trucks in the 1960’s.But the company wished to distinguish itself from the horde of Japanese automakers targeting to promote a new sports car in the Western market. In light of this, the company bought the rights to the Wankel rotary engine design from NSU in ’62 and embarked on improving it before production.
After pinning their hopes for survival on the Wankel, engineers in Hiroshima commenced the refinement process in readiness for production. The company has dubbed the team responsible for the rotary’s development the 47 Samurai. The Cosmo Sport 110S, fitted with a twin-rotor, was first unveiled in public during the 1964 Tokyo motor show and it appeared in showrooms on 30th May 1967.
Even though the Cosmo Sport achieved limited sales figures, Mazda persisted with the rotary engine structure-eventually installing it in everything from a 26-seater bus to family cars. But the majority of motoring fans are more attracted to the RX-7 or RX-8, both of which stood out from the throng of sports car with a crazy appetite for revs. Regrettably, the RX-8’S RENESIS engine came with an unquenchable appetite for oil and petrol, and it lacks the torque to challenge conventional engines.
In addition to its application on the road, the rotary engine was used to power the Mazda 787B to victory in the 1991 Le Mans race. Besides sounding like a swarm of angry bees carrying chainsaws, the orange-and-green racer has achieved the unique honor of being the sole Japanese sports car to ever triumph at the 24 Hours of Le Mans.
Stringent emissions standards have meant that we are not assured of seeing another Mazda rotary engine car. The company maintains that the layout has not been ignored and a hydrogen-powered Wankel has been considered and tests conducted. The 2015 Tokyo motor show featured the RX-Vision that used a hybrid rotary system. But it remains unclear if the strange powertrain will ever become publicly available.
Less than two million rotary-powered Mazdas were ever sold.