Why Do Rotaries Suck?

[JAS-25T]

The rotation of a rotor inside the housing is different to the stroke of a piston. these two cannot be compared.

only the amount of combustions per rotation of the output shaft.

[ylwgtr2]

  FineLine said:

just raggin mate. I have no love for eggbeaters but its no skin off my nose if others like them.

Thats fine....well shut your fu(king trap then ya co(k smoker

[FineLine]

  ylwgtr2 said:

Thats fine....well shut your fu(king trap then ya co(k smoker

ROFL! Eat a dick bitch.

[adznight]

Who is this FineLine muppet anyhow? A patrol, maxima and an R33? Sounds to me like he has some sort of un-natural fetish for all things Nissan. Talk about rubbish cars. Go the Rotor! :)

[FineLine]

  Adzmax said:

Who is this FineLine muppet anyhow? A patrol, maxima and an R33? Sounds to me like he has some sort of un-natural fetish for all things Nissan. Talk about rubbish cars. Go the Rotor! :laugh:

my brakes have rotors.

And I have a box trailer which doesnt move unless I tow it. Sorta like a rotor.

[2LV8ETR]

  FineLine said:

my brakes have rotors.

And I have a box trailer which doesnt move unless I tow it. Sorta like a rotor.

Haha! Touche'

[aDrew_C]

FD RX-7's are brilliant cars, they wouldn't handle like they do if you put a 6 cyl in the engine bay. Nothing wrong with a rotary at all. I don't give two shits about capacity and rpm and all that crap; power/torque for the weight and dimensions of the engine is what means the most in a performance car. You can't seriously say an iron block I6 is a better package?

I hope mazda have success releasing the 16X rotor. With more power, torque, efficiency and less weight I might just be tempted to get a cheap FD and put a 16X in it when they have been around for a while.

[esky_mad]

for a skyline forum there sure is alot of debate regarding rotarys... id like to see a skyline debate on the other side of the fence.

i personally would have no problem jumping into a tough PP13B RX323

[esky_mad]

there was a question regarding supercharging earlier in the thread. dont know if it was answered... either way..

early model 323 + Simmons + Rotary = Win!!

[Birds]

LOL @ piss poor job of blurring out the numberplates on the 323.

Thought I recognised that blower, it looks just like the one strapped to the Windsor in our promo car

Superchargers ftw.

[bigslick]

  Sydneykid said:

the pistons, that produce the power, cycle at 3,000 rpm.

Wow, learn something new everyday. Pistons apparently revolve.

Gary, as has been said, the engine rpm is taken from the output shaft (or eccentric shaft), exactly the same as a piston engine.

[warps]

  FineLine said:

And I have a box trailer which doesnt move unless I tow it. Sorta like a rotor.

Pure gold!!

[sydking]

give me a rx3 anyday.

running 7.2's il be happy

Edited September 16, 2009 by sydking

[Birds]

  bigslick said:

Wow, learn something new everyday. Pistons apparently revolve.

Gary, as has been said, the engine rpm is taken from the output shaft (or eccentric shaft), exactly the same as a piston engine.

Now why didn't I just say this instead of attempting to explain the physics behind it

For that matter rotors don't revolve either because their path is eliptical

[Sydneykid]

  ylwgtr2 said:

I dont care about what capacity it is or isnt......its small....and its light....how big is your 3.9 litre piston engine?and how heavy?

My 2.4 litre pistron engine (Honda K24) puts out more torque and horsepower than the your rotary and it weighs 15 kgs less.

Plus it's a legal under 2.5 litre engine, not a lied about 3.9 litre and it actually does rev to 9,000 rpm not 3,000 rpm.

  Quote

Do you suggest i fit one in my race car?Show me an engine i can walk down to any wreckers and buy and fit in the tiny hole i have that will retain the cars weight at 490kg.....

As well as the afformentioned K24 you could also use a K20 as found in the fast Lotus's, like say the SuperLap 2008 winner or an F20C.

You need to get out more and look at real engines, stop living in '70's.

  Quote

and if we are talking about 3000rpm....well then they produce quite good power for a "slow" spinning engine dont they?

Not compared to a 3.9 litre slow spinning engine

Cheers

Gary

[Sydneykid]

  Birds said:

Gary, by your logic manufacturers of turbocharged vehicles are lying too. Advertising it as a 1.3 litre rotary is no different to marketing a turbocharged 2 litre engine as a 2 litre, which many manufacturers do. Do you want them to say it's really a 4 litre and include an explanation of how their engine works in all marketing literature to avoid any confusion? Of course the idea of it having 1.3 litres displacement was used to marketing advantage, but just like with turbocharged engines you're your own fool if you don't discover for yourself how these engines work. Displacement is somewhat irrelevant anyway, for only racing homologation cares about displacement. Everyone else just wants to know things like how much fuel it uses, how much power/torque it puts out, how big physically the engine is, how long it will last etc. Whatever lies that Mazda may or may not have told, they stop at these variables that people actually care about.

Nice try at muddying the water, the fact is turbocharged or not the capacity of the engine is still the capacity of the engine and a 13B is 3.9 litres. It's an invalid comparison anyway, nobody hides the fact that it's a 2 litre turbocharged engine, but Mazda lie and call a 3. 9 litre engine a 1.3 litre. There is no comparison, next you will be saying just because a 6.2 Chrysler Hemi can switch off 4 cylinders at any one time that it's really a 3.1 litre. The fact remains it's still a 6.2 litre, just like a 13B is 3.9 litres.

  Quote

You're missing my point about your engine speed argument. Your definition of engine speed is based on parts moving inside the combustion chamber...this is very biased towards piston engines, particularly as engine RPM is always taken from a crank shaft in any type of engine. It's just by nature that a piston engine's combustion chamber components move at the same speed as its crankshaft. Again, I ask you, how do you want to measure rotor speed? Or were you planning on taking rotor speed from the eccentric (crank) shaft, where it should rightly be measured from, and dividing that by 3? The eccentric shaft gear ratio is a means by which the engine turns the shaft, the engine can't operate in its intended manner without this part and it is therefore a part of the engine. Whatever ratio or speed changes take place in between the moving combustion chamber parts and this output shaft are irrelevant.

I don't know about you, by my tacho reads ignition pulses, it doesn't actually count the crankshaft revolutions. Tacho's are very simple devices, for a 2 stroke they count how many combuston events per minute and divide it by the number of combustion chambers and that = rpm. Very simple, now do it for a rotary engine and you end up at 3,000 rpm. It's not that hard to understand.

Cheers

Gary

[mad082]

sure a rotor isn't as small as an inline 4 to be used in fwd, but a 3.8L v6 isn't as small as an inline 4, yet mitsubishi used them in the 380. also didn't stop pontiac putting a 5.3L v8 in the grand prix gxp (also the chevy impala SS) and it's also fwd. then there is the host of fwd v8's that cadillac has made over the years. but then they did have massive bonnets. but the new impallas, etc, don't have massively huge bonnets to fit the v8's in, so i'm sure that it wouldn't be that hard to shoehorn a rotary into a fwd.

frankly this debate is as pointless as a nissan vs commodore one. all you get is the typical one sided people arguing against people who are willing to look at the whole picture.

[Sydneykid]

  warps said:

Ah, Gary's just upset that the rotaries are dominating IPRA

What? The current lap record holder at Mallala, Sandown and Winton actually is an RX3 powered by 1.8 litre Mazda 4 Cylinder turbocharged engine with a restrictor. He took a rotary engine out of that car and then started winning and setting lap records.

  Quote

Better tell CAMS that their rotary multiplication factor or 1.8 is wrong.

Interesting history there. Phil Irving OBE, Repco Brabham designer, author of many books, actually did a study on rotary engine capacity in the '70's. Based on sound automotive principles he arrived at a capacity of ~3.2 litres for a 12A. This was submitted to CAMS but was rejected by the then CAMS President John Large. As most people know the Large one was the man most responsible for allowing a Sports Car (Mazda RX7) to race in the Australian Touring Car Championship at the behest of one Allan Moffat. Hence perpetuating an almost bigger lie than 1.3 litres and 9,000 rpm, that being an RX7 is a Touring Car.

Cheers

Gary

[bozodos]

lol you're just pissy that SK keeps rolling you Marc, awesome thread would read again! (now for someone to link this thread to a rotor forum ha ha ha)

[Sydneykid]

  mad082 said:

frankly this debate is as pointless as a nissan vs commodore one. all you get is the typical one sided people arguing against people who are willing to look at the whole picture.

It's actually not pointless, well not on my behalf anyway. Because I'm talking about facts, irrefutable facts. Any comments on "this is better than that" are based on solid numbers, engine capacity, RPM, horsepower, torque, weight and fuel consumption. I simply post the facts and then the readers can make up their own minds. How many people had actually questioned Mazdas capacity measurement accuracy before this thread? And the RPM questions?

As for one sided, I actually take offence to that. I have built many rotary engined road and race cars, the first one (an RX2) back in the '70’s. One (an RX7) was the only car ever to win both NSW and Vic Improved Production Championships in the same year. So my opinions are based on what I know from years of personal experience with rotary engines and then by applying simple logic. I can sure as hell see the whole picture, including the years of subterfuge and supression of the true facts.

Cheers

Gary