APART from providing endless schoolboy sniggers the Wankel rotary engine is one of the greatest near-misses of 20th century engineering. It promised to revolutionise the bikes we rode and cars we drove, but despite decades of work never quite overcame the problems that prevented it from becoming a mainstream hit.
We won’t go into detail about how Wankels work, since it’s a slightly mind-bending concept based on a mind-bending movement that seems to virtually defy logic (see a great animation here). But the basic idea of getting rid of all the reciprocating bits of a normal engine – the pistons, con-rods, valves – and replacing them with a design that does the same suck-squeeze-bang-blog sequence using purely rotating parts is, frankly, genius. Sadly it’s genius that’s hamstrung by a couple of flaws - most notably difficulties in sealing the rotor tips - which have effectively ended its challenge to conventional piston engines.
We all know about Nortons and Suzuki RE5s, but there has been a host of other Wankel-engined bikes over the years, from prototypes to full production models. Here’s our top 10 pick.