So goes the saying. Indeed. And it went on for half-a-century.
The Wankel rotary engine promised to put an end to the Ups-and-Downs experienced by conventional piston engines. In reality, the Dream was also a Nightmare, posing tremendous, if not insurmountable problems for engineers.
In the early 1960s, Mazda took on the Wankel, and went on to develop a fully working engine which debuted in the Cosmo model of 1967. The rotary engine was powerful, smooth, and free-revving. However, issues with rotor sealing resulting in high fuel consumption and dirty emissions continued to impose serious constraints on its acceptability especially in an age of rising concerns with Global Warming.
The last Mazda model, RX-8, saw its final production in 2012. But research is still ongoing on a future ‘clean’ version. Hopefully, it will go round and round more happily the next time.