Oval Pistons

[DJohn77284 at aol.com]

I think for oval pistons you have to read Honda.

Back in the late 70's Honda had a 4-stroke NR500 motorcycle racer. It was a
V4 that thought it was a V8. That is, by using oval pistons, 8 valves per
cylinder, two plugs per cylinder and two conrods per cylinder, the breathing
capacity was increased to that of a V8 of similar size. The governing racing
body had previously put a restriction of 4 cylinders maximum on the 500cc
class, hence the elegant engineering. I think the rev limit was somewhere
like 22 - 23,000rpm but despite their efforts, Honda couldn't compete with
the two strokes.

After that, while Honda diverted it's racing efforts to two strokes, the
comercial division brought out a road going version of the racer, called
NR750. Only 700 were ever made and the cost was way over the top at #38,000.
I remember seeing one at a motorcycle exhibition and it didn't look worth the
money - loads of plastic on the outside with talk of loads of titanium on the
inside. If you want to see one in the flesh I think the best place is the
Suzuka 8 Hours where the track marshals use them as run-abouts.

Regards,

Dave.