Wankel engines so. Because we just saw one again. At GeKra motors in Dieren is a former Norton Wankel police motor. And the engine that almost caused Suzuki's bankruptcy, the RE5, we rode on it and we enjoyed the unique 'round' engine sound.
Wankel engines missed the boat
But the Wankel concept did not make it. A high fuel and oil consumption, the thermal ineffectiveness so that the speed can be roughly read by the color red of the exhaust system. The wear on the sealing strips was also a thing.
Up to approx. 1970, the seals between the corners of the rotor and the drum wall still had many problems (the motors tend to wear out considerably at this point). From around 1970 these problems are largely solved and the Wankel is just as reliable as an 4 stroke from the same period.
But first there was hope
But when the Wankel engine was just there, it got all the attention from a lot of engine manufacturers. Because the idea was great: a small, powerful, vibration-free motor with a minimum of moving parts. An engine whose production costs are also low too. Which engine manufacturer was not waiting for that now.
So there was a whole bunch of motorcycle makers that went on motorcycle block hunting. And they came (under license) from NSU and Sachs. The prototypes that resulted from that were often great fun trials, just like being more open-minded things from a pioneering era. And the first wankel engine? It was in an IFA / MZ. Anton Lupei, designer Erich Machus and test engineer Roland Schuster plus technicians Hans Hofer and Walther Enert built a rotary motor in the bicycle section of an MZ BK 351. The 24 pk strong engine was coupled to the existing MZ gearbox, which was otherwise identical to that of the BMW R25. That prototype was tested seriously. It still exists and currently there are more than 38000 kilometers on the clock.
Shopping for groceries
The second prototype was made in 1965 using the now well-matured Fichtel & Sachs Wankel engine, which was available worldwide from that year. Fichtel and Sach was the second licensee, and Sachs used the Wankel engine as a small, light engine for things like lawn mowers and chainsaws. But for the further developments that were necessary to control the wear of the sealing strips in the block and the extremely high operating temperature? There was simply not enough money in MZ's cash for that.
In 1972, Yamaha obtained a Wankel license and a prototype was quickly made, the RZ201. That was presented at the Tokyu Motor show. The 600 cc twin rotor was liquid cooled and delivered an impressive 66 hp at 6.000 revolutions. The motorcycle looked great, but the fact that it was still far from the practice was apparent, among other things, from the lack of heat shields in the exhaust section.
Suzuki's almost bankrupt
In 1973, Suzuki presented the RE5 at the Tokyo Motor show after a development time of three years. Its design was experienced as strange. But that was because Suzuki Giorgietto had hired Guigiaro, the car designer, for the looks of the instrument panel. For the rest, the machine looked very much like the Suzuki GT750. The RE5 was heavy, expensive, complicated and thirsty.
In 1974 Fichtel & Sachs came up with the Hercules W2000 with a 294 cc. 20 (later 32) hp air-cooled Wankel engine with a single rotor. And that Hercules was the first truly mass-produced Wankel motorcycle.