WeeeeeeeeHAW! 11,000 rpm!

I could see @residentalien riding this…:wink:

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Thanks for the thought Paul , maybe in my younger days , but close to twice that speed now days :rofl:



Of course it was nowhere nearly that fast, but regarding rpm, when I was 16-17 I would run my little two cylinder 4-stroke 1982 Honda 125TD twin all day at 14,000rpm. :smiley: It was about 125km/h = 78mph.


14,000rpm? Pah!
In the 1960s Honda had a 125cc race bike (RC149) that produce power at 18,000 rpm - 5 cylinders, 20 valves! If you think that is nuts, they also made a 50cc twin race bike (RC116) that revved to 21,500 rpm.


The rpms were high. The stroke and burn times were short. Honda had to lower the compression ratio and the fuel octane. High octane was still burning well after exiting the exhaust valve and made less power than low octane.

On the subject of 11,000 rpm…

I’ve never wanted a Porker, but I might have just changed my mind.


Absolutely incredible machine.

I could certainly live with a SC: I have always loved the sound of a Porsche flat six.

IIRC, maybe in the 80s, Honda had an engine with oval pistons, to make room for more valves.

The engine did have more valves per cylinder but that was a consequence rather than the purpose. The purpose was to build a V8 500cc engine when the regs prevented more than four cylinders. Check the engine cutaway in the link. The pistons even had two conrods each.


There are a few folks vintage racing them. Unfortunately there are zero engine replacement parts. When an engine needs an overhaul it is finished.

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If I ever knew that that was the configuration of the engine, or the why of it, it’s certainly lost to the (my) ages! That’s nuts!

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Creative little buggers thks for posting I’d never heard of it