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Is a well designed V8 smoother than rotary?

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Old 02-03-2010, 01:11 PM
  #26  
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Originally Posted by 8 Maniac
that post = fail. Whether they mean a smoother power deliver or overall feel of the engine vibrations in the car, it's something that can basically be measured or rated, regardless of opinion. If it was really close, you could sum it up to inaccuracies, but it's not really an opinion thing.
Sorry but to ask which is "smoother" a V8 or Rotary is very vague. Are we talking about power delivery? Engine vibrations? What V8 are we talking about, there are literally 1000's. Too many variable's to very basic question.
smooth (sm)
adj. smooth·er, smooth·est
1. Having a surface free from irregularities, roughness, or projections; even. See Synonyms at level.
2. Having a fine texture: a smooth fabric.
3.
a. Free from hair, whiskers, or stubble: felt his smooth cheek after the close shave.
b. Having a short dense flat coat. Used of dogs.
4. Having an even consistency: a smooth pudding.
5. Having an even or gentle motion or movement: a smooth ride.
6. Having no obstructions or difficulties: a smooth operation.
7. Serene: a smooth temperament.
8. Bland: a smooth wine.
9. Ingratiatingly polite and agreeable.
10. Having no grossness or coarseness in dress or manner.
v. smoothed, smooth·ing, smoothes
v.tr.
1. To make (something) even, level, or unwrinkled.
2. To rid of obstructions, hindrances, or difficulties.
3. To soothe or tranquilize; make calm.
4. To make less harsh or crude; refine.
Old 02-03-2010, 04:14 PM
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Mazda says...

V6 < 13b < V8 < 20b < V12
Old 02-03-2010, 04:42 PM
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Originally Posted by reddozen
Mazda says...

V6 < 13b < V8 < 20b < V12
I added the inline 6 which is equivalent in smoothness (torque fluctuation) to a 2 rotor.

I4 < V6 < I6 ≡ R2 < V8 < R3 < V12

I'm curious to know where the H4 and H6 fall in this arrangement.
Old 02-03-2010, 04:44 PM
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V10 is inherently unbalanced, so I'm guessing it falls between V8 and R3.
Old 02-03-2010, 06:16 PM
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why isnt a 1 rotor in that example? or a 3cyl?

:O HUH HUH WHY
Old 02-03-2010, 10:09 PM
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Old 02-04-2010, 12:44 AM
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Revised after a bit of reading:
I4 < H4? ≡ V6 < H6? < I6 ≡ R2 < V8 < V10 < R3 < V12

Added the V10 and the flat engines, based on torque fluctuation.
Old 02-04-2010, 08:31 AM
  #33  
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Originally Posted by m477
I know.... it's not 9500rpm.
So you'd rather have an extra 1100 rpm's that completely fall off on power than nearly triple the horsepower, scraping the bottom of the bowl?

Nevermind, saw you're last couple posts, you're a ball of positive energy.
Old 02-04-2010, 09:25 AM
  #34  
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Originally Posted by dillsrotary
So you'd rather have an extra 1100 rpm's that completely fall off on power than nearly triple the horsepower, scraping the bottom of the bowl?
As for me, it all depends on throttle control, irrespective of horsepower or RPM. The higher the horsepower, the finer the precision of throttle control should become. I think the high redline helps in granting a finer degree of throttle control, kind of like a micro-surgery movement scaler(?).
Old 02-04-2010, 09:37 AM
  #35  
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Originally Posted by dynamho
I added the inline 6 which is equivalent in smoothness (torque fluctuation) to a 2 rotor.

I4 < V6 < I6 ≡ R2 < V8 < R3 < V12

I'm curious to know where the H4 and H6 fall in this arrangement.
I4 < V6 < I6 < 2 rotor < V8 < 3 rotor < V10 =/< W10 < V12 =/< W12 < 26B < W16?
Old 02-04-2010, 10:14 AM
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Originally Posted by SayNoToPistons
I4 < V6 < I6 < 2 rotor < V8 < 3 rotor < V10 =/< W10 < V12 =/< W12 < 26B < W16?
Since a V10 is rough compared to a V12, and mazda says that a 3-rotor is "almost as smooth as a V12" That the 3-rotor would be smoother than the V10.
Old 02-04-2010, 01:25 PM
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Yes. I think so. V10 is inherently unbalanced. So an R3 would be smoother. V12 is supposed to be as smooth as they come.
Old 02-04-2010, 04:14 PM
  #38  
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Plus a v12 is the sexiest layout anyway. The only reason any person drives a non v12 car is because of cost. 12 is always the best for everything. No one wants a v6, or even a v8. v12 is what it's all about.
Old 02-04-2010, 09:29 PM
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v8s should not be smooth. at least not at idle.



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Old 02-05-2010, 04:57 AM
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What about SOHC and DOHC lol
Old 02-05-2010, 06:22 AM
  #41  
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Old 02-06-2010, 05:49 PM
  #42  
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Originally Posted by 8 Maniac
Neither is the RX-8. The redline on the 8 is 9k. The rev limiter on the other hand, is slightly higher. I'm not sure if it quite goes to 9500 stock though. The tach lags a bit so it's typically a couple hundred rpms lower than what it looks like. Either way, it doesn't matter since you have less power in the 9k range. You can rev to 9k+ (and it's still fun), but not very useful as far as power goes. The 8 is best shifted at 8700 rpm. The m3 has peak power at its redline (8300 rpm) and a rather flat torque curve up until that point as well. My point is, the redline means nothing. I realize the point of this discussion is smoothness, but the thing about the V8 redline is that it's most likely making significantly higher power at that redline. How many renesis engines are putting down more power than the M3? What rpm do they stop making power at?
I'm not sure what peak power has to do with this. Look around this forum and you'll find post from people admitting that they were cruising in 4th on the expressway, mistakenly thinking they were in 6th for a while before realizing their mistake. I don't think you'll ever see anyone claiming that about any V-8 engine.


Originally Posted by dillsrotary
Nevermind, saw you're last couple posts, you're a ball of positive energy.
Sweet, I've got my very own stalker on the forum now.
Old 02-06-2010, 06:20 PM
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Originally Posted by m477
I'm not sure what peak power has to do with this. Look around this forum and you'll find post from people admitting that they were cruising in 4th on the expressway, mistakenly thinking they were in 6th for a while before realizing their mistake. I don't think you'll ever see anyone claiming that about any V-8 engine.
I'm not sure what the point of that post is. That's just as much about gearing as it is about rpms. If we're still talking smoothness, I'd imagine there is a V8 that is just as smooth as a rotary throughout the rpm range. The point still stands, the redline means nothing without an equal amount of power when compared to another car. If 2 cars have the exact same power curve over different rpm ranges, then yes, the car with a higher redline will be faster.
Old 02-06-2010, 06:41 PM
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Originally Posted by 8 Maniac
I'm not sure what the point of that post is. That's just as much about gearing as it is about rpms. If we're still talking smoothness, I'd imagine there is a V8 that is just as smooth as a rotary throughout the rpm range. The point still stands, the redline means nothing without an equal amount of power when compared to another car. If 2 cars have the exact same power curve over different rpm ranges, then yes, the car with a higher redline will be faster.
Name one V-8 that's as smooth as a rotary at 9000rpm.
Old 10-04-2021, 10:52 AM
  #45  
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Originally Posted by Vlaze
Not sure why one would care if a V8 was smooth or not. With a V8 you want the roar of the motor and sheer power of the beast unlocked. That includes the trembling and vibrations from the excess power. For a rotary smooth is nice, but for a V8 no danke.
i guess theres some people out there that want a quiet, "smooth" V8 out there lol
Old 10-06-2021, 12:05 AM
  #46  
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Originally Posted by RyanAlexander
i guess theres some people out there that want a quiet, "smooth" V8 out there lol
11 years too late. Not quite the record here, but it's getting up there.

But since we are here... V8's could be smooth if that's your goal. See the below Lexus commercial:


As for American V8's, usually, they are in vehicles like trucks and pony cars where the vibration either doesn't matter too much or could actually add to the character of the car. The LT1 in my Camaro now is far from smooth, but it's more or less supposed to be that way. I think OHV V8 will also be a bit harsher than DOHC V8 by nature since the moving masses tend to be heavier(pushrod, bigger valves vs. bucket/rocker, smaller valves).

Then there is the flat-plant crank V8... Those will shake more but rev higher.

So yeah, it depends on if you want it to be smooth or not.

Last edited by UnknownJinX; 10-06-2021 at 12:08 AM.
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