Street port question
#26
Rotary Enthusiast
iTrader: (1)
Originally Posted by REVHED
Ok, what I said was uncalled for.
If there is a standard way to figure displacement for a rotary, I would be pleased to know. I am not trying to debate, basically I want to know how Mazda figures it to be 1.1 Liters.
Sorry to thread jack...
#27
Old Fart Young at Heart
iTrader: (6)
I'm going to venture a guess that if you have an engine apart, you could assemble the front iron, #1 housing, e-shat and rotor, lay it out with the e-shaft pointing up, the rotate the rotor until you see the maximum volume in the chamber and measure it. I would also venture a guess that the maximum volume occurs when the 2 opposing rotor tips are horizontal/level to the world, if the engine was stood up. Hardest part would be keeping enough of a seal so the liquid didn't seep out before the chamber was full and an accurate measurement could be taken.
Loki, I believe I owe you an apology on the compression comment. As I thought about it more, the more volume you cram into a finite space the more the CR raises. The way I was looking at it when I posted my comment was the fact that you cannot increase the volume of the combustion chamber on a rotary, as you can a piston engine. And now that I think about how I came to the conclusion on the earlier post on CR, I don't know what I was thinking. I've got to quit staying up 24 hours +.
I'm sure there are probably some good technical papers out somewhere that expain how engine size is figured in a rotary, I haven't come across one. Comparing a 4 stroke engine to a rotary, cu. in. for cu. in., to me just does not compute. What a 4 cycle does for one combustion event, it takes a rotary, looking at it in an odd way, only 3 steps. This idea is, of course, discounting engine revolutions per combustion event per combustion chamber.
If this doesn't make any sense, yes, I still need some sleep.
Loki, I believe I owe you an apology on the compression comment. As I thought about it more, the more volume you cram into a finite space the more the CR raises. The way I was looking at it when I posted my comment was the fact that you cannot increase the volume of the combustion chamber on a rotary, as you can a piston engine. And now that I think about how I came to the conclusion on the earlier post on CR, I don't know what I was thinking. I've got to quit staying up 24 hours +.
I'm sure there are probably some good technical papers out somewhere that expain how engine size is figured in a rotary, I haven't come across one. Comparing a 4 stroke engine to a rotary, cu. in. for cu. in., to me just does not compute. What a 4 cycle does for one combustion event, it takes a rotary, looking at it in an odd way, only 3 steps. This idea is, of course, discounting engine revolutions per combustion event per combustion chamber.
If this doesn't make any sense, yes, I still need some sleep.
#28
Hunting Skylines
Join Date: Apr 2001
Location: Brisbane, Queensland, Australia.
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Displacement or swept volume on a rotary is calculated the same as a piston engine. The difference between the maximum chamber volume (which occurs at 180* of e-shaft rotation) and minimum chamber volume (0* degrees e-shaft rotation) times the number of rotors.
#29
Old Fart Young at Heart
iTrader: (6)
Originally Posted by REVHED
Displacement or swept volume on a rotary is calculated the same as a piston engine. The difference between the maximum chamber volume (which occurs at 180* of e-shaft rotation) and minimum chamber volume (0* degrees e-shaft rotation) times the number of rotors.
#31
Old Fart Young at Heart
iTrader: (6)
Originally Posted by REVHED
Displacement or swept volume on a rotary is calculated the same as a piston engine. The difference between the maximum chamber volume (which occurs at 180* of e-shaft rotation) and minimum chamber volume (0* degrees e-shaft rotation) times the number of rotors.
Originally Posted by trochoid
Since I am too lazy to calculate the difference in rotation between the e-shaft and rotor, where does this position the rotor when the e-shaft is at 180*?
Originally Posted by REVHED
When one of the apexes is pointing straight down.
The 180* or e-shaft rotation makes sense, when comparing it to how displacement is determined in a piston engine.