View Full Version : OT: Rotary Engines

10-29-2006, 09:32 AM
Something got me thinking about these last night and I've got one of those nagging questions. I assume they have a compression ratio, but how would one increase it? The only thing I could come up with was changing the curvature on the rotor face between the tips. Kind of like a dome on a high compression piston. My problem with that is that I think it would reduce displacement. I'm not planning on doing it, or even working on one, I'm just curious. Anyone know?

A.K. Boomer
10-29-2006, 10:06 AM
I believe you would have to leave that curvature alone, its a pre-determined arc that just clears the stationary surfaces, but i think with some rotors there is an internal pocket between the rotortips that could just be filled (kinda like a dished piston --- but maybe i was looking at a turbo rotary and they had this to reduce the ratio),,, anywho -- their may also be a stationary surface that can be reduced close to where the plug goes but that would take an entirely new block, I never liked the rotary for all kinds of reasons and you just brought up another, they are not very fuel efficient --- they really arent even a true rotary when you get right down to it -- they are more of an occilating engine and they do waste power this way -------- a mild overheat of the engine and you throw it away...

Contrary to popular belief the piston engine does not waste any energy in the reciprication motion itself except in the form of friction...

10-29-2006, 02:23 PM
This might explain it:



The rotors have pockets machined into them to reduce compression - fill in the pocket and compression goes up. I think I'd use a turbocharger rather that try to keep the rotors balanced after filling.

10-30-2006, 12:02 AM
Ok, now I understand. I always though of the rotors as being "flat" across, the recess makes sense as it's essentially the combustion camber. Don't worry about me boosting one of these, I prefer flat 6's :)