Rotary Car Club - View Single Post

Monkman33 · 06-03-2011, 07:38 AM

Guys, displacement by definition is the volume displaced by one revolution of the crankshaft or e-shaft in this case. doesn't matter if it is 2 stroke, 4 stroke, or not.

You guys are all going off on this "when does it ignite, and when does it do this or that?" It's all moot.

total volume displaced over 1 crankshaft revolution = Displacement. It is consistent across the board. There is no Mazda conspiracy to hide its actual displacement. A 6.0 liter engine is a 6.0 liter engine, whether its 2 stroke or 4. You can't use the "Getting back to face 1" argument due to the trochoidal nature and the 3:1 ratio. If you do use this argument, then you have to divide the final result by 3 because of the 3:1 ratio.

Now, what is the one consistent thing in all the engines? output RPM. Displacement is based on 1 of these revolutions. So any other attempt to define definition by more than 1 revolution is incorrect. 1 revolution is the consistent factor across the board. Te reason racing bodies use a multiplier is to even the playing field just like they do for 2-stroke engines. The advantage a 2 stroke has is that is happens to fire its full displacement per revolution, just as a rotary does, where as a 4 stroke only fires half of its displacement per revolution.

Don't confuse revolutions of the rotor versus the crank/eshaft. You'll end up chasing ghosts.

06-03-2011, 07:38 AM	#27
Monkman33 Still Building my FD Join Date: Jun 2009 Location: Pasco, WA Posts: 255 Rep Power: 16	Guys, displacement by definition is the volume displaced by one revolution of the crankshaft or e-shaft in this case. doesn't matter if it is 2 stroke, 4 stroke, or not. You guys are all going off on this "when does it ignite, and when does it do this or that?" It's all moot. total volume displaced over 1 crankshaft revolution = Displacement. It is consistent across the board. There is no Mazda conspiracy to hide its actual displacement. A 6.0 liter engine is a 6.0 liter engine, whether its 2 stroke or 4. You can't use the "Getting back to face 1" argument due to the trochoidal nature and the 3:1 ratio. If you do use this argument, then you have to divide the final result by 3 because of the 3:1 ratio. Now, what is the one consistent thing in all the engines? output RPM. Displacement is based on 1 of these revolutions. So any other attempt to define definition by more than 1 revolution is incorrect. 1 revolution is the consistent factor across the board. Te reason racing bodies use a multiplier is to even the playing field just like they do for 2-stroke engines. The advantage a 2 stroke has is that is happens to fire its full displacement per revolution, just as a rotary does, where as a 4 stroke only fires half of its displacement per revolution. Don't confuse revolutions of the rotor versus the crank/eshaft. You'll end up chasing ghosts. __________________ Uh.... hi.