hosrom_951

Haha.........

Porsche-O-Phile

Screw four cylinders, just have one huge oval-shaped one!

Jfrahm

Honda tried that, to make a V8 motorcycle engine into a V4 to get past some pesky rules. It kinda worked.

-Joel.

Skunk Workz

THe NR750 was the end result...150 hp was what it had back when you needed an ordinary 1000+cc's bike to get the same hp. Don't know if it still has the world record top speed for an unmodified 750...but if I'm not wrong,it cost about as much as 4-5 ordinary bikes too,and was just made in a VERY limited series... so just for the rich guys,I presume.

Eight valves and two rods per piston does make for a trick engine,though.

Tomas L

The first version was a 500 cc bike meant to compete in 500 cc road racing against the two strokes. The power level was almomst at two stroke level but it was to heavy. IIRC it had a stroke somewhere around 21 mm and revved well over 20k rpm...
I think piston ring sealing was the main problem with this engine. Imagine yourself how an oval ring can expand against an oval cylinder...

Skunk Workz

I know...been working on one NR750-engine,when I was a motorcycle mechanic...luckily I didn't have to bore the thing,(how the h**l do you do that on an oval cylinder?? ) I just changed the piston rings and did my best to flexhone it evenly troughout the bore. Not an easy task,I tell you that. And the pricetag alone almost had you pissing your pants when working on it....

chapstic951

You know the displacement is right when you can stick your head in the cylinder....

Chris White

which head....

Chris White

did I say that outloud?

BoostGuy951

I think you typed it.

You got some pics or what?

I'm so excited I think I have hit refresh over 100 times today.

Chris White

The holes just looked too big, so I figured I’d better fill em’ up with something.

Chris White

hosrom_951

That's a beauty Chris!!!