View Single Post
Old 03-26-2009, 01:57 PM   #13
Cp1
Rotary Fanatic
 
Cp1's Avatar
 
Join Date: Mar 2008
Location: Sask, Canada
Posts: 181
Rep Power: 18
Cp1 is on a distinguished road
Quote:
Originally Posted by vex View Post
interesting. Thanks for the info!

I was coming to that conclusion and was wondering why people hadn't already done it. You answered that for me! I'm curious though if our engines are supposed to be balanced while rotating, wouldn't the mass become negligible at the bearings or is there too much torque being applied there from the combustion chamber of the opposite rotor?
yes the assembly as a whole is pretty well balanced but during ignition the force is pushing the rotor (or the conrod big end) directly into the bearing where it deforms slightly it is this force that a roller or ball bearings cant take over time and on a journal the oil cant be compressed enough to allow metal on metal contact. this force its akin to hitting it with a hammer to get it to spin. couple that with the increased wear from only having a very few points of contact on the bearing roller surfaces and you have extremely high pressure points. a ceramic ball riding in a steel v groove only has contact at two infinitely small points creating infinitely high pressure. so the ball or the groove must deform slightly to work.

Think of the forces acting on the bearings as engine knock. the rotating momentum is what saves the bearing like the engine from complete destruction as it transfers the force fairly quickly but it doesn't eliminate the shock or the "bang" altogether this force with each detonation will simply destroy an off the shelf roller bearing or any made for turbo ball bearing. and when coupled with the increased pressure it creates and the increased friction and design problems of assembling them into the motor it just isn't worth it.
__________________
Quote:
As the length of an online discussion nears infinity, the probability of a comparison involving Hitler or the Nazis approaches unity.
Quote:
Re-upholster your FD's console or anything else... ask me how! Thread: http://rotarycarclub.com/rotary_foru...ead.php?t=5157

Last edited by Cp1; 03-26-2009 at 02:08 PM.
Cp1 is offline   Reply With Quote