srm858

Someone made a note a while ago, that the rotary engine at 9000 rpm on the tach is actually only turning at 3000 rpm. Does the tach show combustion per minute or revolutions of the rotor per minute? I had always assumed it was revolutions of the rotor, but the comment I read got me thinking about it.

zoom44

it's revolutions per minute of the output shaft.

srm858

Zoom44, thanks for the response, makes sense. It's just that you get 3 firings per revolution, so it thought there was a slim possibility that the tach was reading these firings. I hate it when people post things that could possibly be true, but are wrong.

93rdcurrent

Actually my understanding is that the eccentric shaft moves faster than the rotors in the engine... It has to do with the Wankel design. Here's a link: http://www.rotaryengineillustrated.com/RE101.html .

zoom44

that's what i said?!

93rdcurrent

Sorry you posted while I was searching for the link. You said the same thing...

zoom44

and i went to get the link and came back and you had posted it hehehe. great minds etc etc

93rdcurrent

That was kind of a hard explanation to find links for...