Teh E36 M3 wrote:Given the remarkable outputs of the latest generation of V6s that may be an out of date premise. To me, the bottom line is that while I love rotaries, they are a less efficient design than recips when you consider output relative to fuel burned. Hell, even a pushrod V8 (LS1) in stock trim produces over twice the torque of a RX8 while getting better gas milleage. What you rate the displacement at is brain candy (mental masturbation?), and little more.Pardon my ignorance here. I've only seen them apart, but haven't held the pieces in my hands.
Seems like you have three combustion surfaces in each housing. I see them like three pistons/cylinders. If each of these is 650cc's (as demonstrated above), multiply 650 by 3 by 2 housings. 3.9l? It doesn't matter though.
Regardless, rotaries give you the horsepower of a good v6, weight of a 4 cylinder, torque of a four, and fuel efficiency of a good v8.
And that car is effing fast regardless of what it has under the hood. He must have thanked god when that 'chute blew.
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April 26, 2011 8:52 a.m. kreb Dork
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April 26, 2011 8:55 a.m. tuna55 SuperDork
In reply to kreb:
Exactly. Displacement is useful for comparing engines that are similar in function. Two stroke to Two stroke. Four stroke to Four stroke, rotary to rotary, steam to steam.
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April 26, 2011 9:08 a.m. dculberson Reader
Here is my OPINION and I will use CAPS to say why you are WRONG even though it is a trivial useless metric that means nothing. Despite it being opinion, I can and still will argue vehemently that there is a right and a wrong one to hold. Your mother was a hamster and your father smelt of elderberries!! Now go away or I shall taunt you a second time!
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April 26, 2011 9:14 a.m. Javelin SuperDork
dculberson wrote:
Here is my OPINION and I will use CAPS to say why you are WRONG even though it is a trivial useless metric that means nothing. Despite it being opinion, I can and still will argue vehemently that there is a right and a wrong one to hold. Your mother was a hamster and your father smelt of elderberries!! Now go away or I shall taunt you a second time!
Que? I thought all parties were having a pretty good conversation with no name-calling or trolling.
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April 26, 2011 9:23 a.m. 92CelicaHalfTrac SuperDork
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April 26, 2011 9:33 a.m. dculberson Reader
Javelin wrote:
dculberson wrote:
Here is my OPINION and I will use CAPS to say why you are WRONG even though it is a trivial useless metric that means nothing. Despite it being opinion, I can and still will argue vehemently that there is a right and a wrong one to hold. Your mother was a hamster and your father smelt of elderberries!! Now go away or I shall taunt you a second time!
Que? I thought all parties were having a pretty good conversation with no name-calling or trolling.
Sorry, just bustin your chops, man. I'll stop.
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April 26, 2011 9:54 a.m. SVreX SuperDork
alfadriver wrote:
While I don't want to poke my head into this debate, the 2 stroke is a different cycle than the 4 stroke. the rotary is a 4 cycle, just like CVCC and HCCI engines are. So how you want to debate it should not factor in a 2 cycle.
They are ALL different. Displacement is still volume.
And 2 stroke displacement is measured exactly the same way as 4 stroke.
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April 26, 2011 9:56 a.m. SVreX SuperDork
Javelin wrote:
dculberson wrote:
Here is my OPINION and I will use CAPS to say why you are WRONG even though it is a trivial useless metric that means nothing. Despite it being opinion, I can and still will argue vehemently that there is a right and a wrong one to hold. Your mother was a hamster and your father smelt of elderberries!! Now go away or I shall taunt you a second time!
Que? I thought all parties were having a pretty good conversation with no name-calling or trolling.
Yeah, but the serious name-calling threads got locked, so it's gotta move somewhere!
...just kidding.
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April 26, 2011 9:57 a.m. Teh E36 M3 HalfDork
I thought it was an interesting discussion too. Not sure about the masturbation bit, but to each his own.
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April 26, 2011 11:20 a.m. Jerry From LA HalfDork
Am I in time to add more annoyance to the proceedings? From what I understand, the reason sanctioning bodies double the rotary displacement has to do with one lobe filling while another is firing. Since each cylinder on a piston can only fill OR fire, the rotary's ability to do both simultaneously makes direct displacement comparison with a piston engine unfair.
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April 26, 2011 11:27 a.m. alfadriver SuperDork
SVreX wrote:
alfadriver wrote:
While I don't want to poke my head into this debate, the 2 stroke is a different cycle than the 4 stroke. the rotary is a 4 cycle, just like CVCC and HCCI engines are. So how you want to debate it should not factor in a 2 cycle.
They are ALL different. Displacement is still volume.
And 2 stroke displacement is measured exactly the same way as 4 stroke.
That's not what I meant. But if you want to take it that way, go for it.
There's also no sanctioning body in the world that says that a 125cc two stroke is the same as a 4 stroke. Just like there's no sanctioning body that says a 1200 or 1300 cc wankle is the same as a piston 4 stroke.
It IS different.
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April 26, 2011 4:02 p.m. dean1484 SuperDork
alfa driver wrote: There's also no sanctioning body in the world that says that a 125cc two stroke is the same as a 4 stroke. Just like there's no sanctioning body that says a 1200 or 1300 cc wankel is the same as a piston 4 stroke.
It IS different.
The problem is that sanctioning bodies did not take a technical look at the rotary versus piston engine. They strictly looked at performance potential and for classification purposes used a 2x multiplier of mazda's wankel designation of 12a or 13b in order to have "equality" with in there classification system. I am betting there was absolutely no discussion as to power per revolution or displacement per revolution. It was just a simple arbitrary formula of 2x used to put rotaries in to what ever car classification system that they may have. This is what needs to be separated from all the actual technical assessment of the rotary and trying to use it to justify a displacement comparison between it and a piston engine. The two are totally separate.
I am thinking that this is what has started the whole debate. (Yes I am blaming SCCA LOL)
Gees I post a simple video, go away, I come back to a 3 page read. Fascinating stuff!!! please continue with the debate. I quite honestly don't know who is correct. Depending on the rule set you establish I can see the merits to several of the formulas put fort so far.
Please carry on!!!!
