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rotary engine capacities

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amazeer Bishop of Volkswagenism

3,029 posts · joined Nov 2005 ·

#460184
Can someone scan page 6-4 article 2.1 of the 2006 CAMS manual for me. Im kinda scared by all these rumours of changes to rotary capacity changes and CAMS havent sent out my manual yet.
PRICKS

dutchy Slammed & Awesome Dubber

76 posts · joined Oct 2005 ·

#460202
I havent got mine either yet,but hopefully they have upped the capacity Ill have more of a chance on the circuit,no problems on
a hillclimb chickenfu.... engines are hopeless..
🤘

pringa8 Seriously Crusin Dubber

132 posts · joined Feb 2006 ·

#460207
Give the National office a call, although I imagine you'll get a different answer each time!

They really are the Confederation Againsts Motor Sport...

amazeer Bishop of Volkswagenism

3,029 posts · joined Nov 2005 ·

#460218
Im afraid the factor hasnt gone up, its gone down apparently.

This is an email which was forwarded onto me.
Regarding the Rotary equivalence factor please note the following which I hope clears it up;

The generally applied equivalence factor is now 1.5 unless specified otherwise in a categories regulations.

In Improved Production the following applies to Rotaries - Normally Aspirated the factor is 1.8 and Super/turbocharged is 3.06 In Sports Sedans it is 1.75. In PRC for the purposes of weight calculations it is 1.8 for normally aspirated then plus 1.6 where super/turbocharged rotary

If you have any further queries please feel free to call me.

Regards,

Mark Zellner
Sporting and Technical Officer
Confederation of Australian Motor Sport Limited

Ph: 03 9593 7784
Fax: 03 9593 7700

Clear it up? No, it opens more questions. Like why on the CAMS website is this change not noted anywhere (why does the search function suck so much) and why does the 2006 NSW Supersprint championship rules still have the old rule of blanket 1.8. What is the factor for? Is it to provide a parity? Why is the parity different depending on what class you run? Why does it still differ from the FIA rule which I believe is a blanket 1.4? Why dont they just ban the horrible sounding piles of turd altogether 🙂

[ Edited on 1-3-2006 by amazeer ]

amazeer Bishop of Volkswagenism

3,029 posts · joined Nov 2005 ·

#461891
pringa8 wrote:Give the National office a call, although I imagine you'll get a different answer each time!

They really are the Confederation Againsts Motor Sport...
Done that, I have 2 answers, one from zelner and one from Michael Smith. Its like a bad comedy movie.


YES rotary boys are in a feeding frenzy.

Improved production 1.8
Sports sedan 1.7
Just about everything else 1.5

depending on what class you run (these arent my figures)
10A 1473cc
12A 1719cc
13B 1962cc
12A turbo 2922cc
13b turbo 3336cc
20B 2943cc
20B turbo 5003cc

As far as I can recall, there arent too many if any rotaries in the hillclimb series, possibly because they were out of the league. However, with the new figures popping 12A turbos under 3 litre, 13B NA under 2 litre, its tipped the scales more in their favour. Personally I cant see how the rate can change depending on what class you are in. If an engine has a 1.5X advantage, its that same figure no matter where it runs. I mean... if you put a 1916 in a street car its 1916, if you take it out and put it in a sports sedan its 1916, nothing changes that. For some inexplicable reason it does change with a Wankel????

flashman Seriously Crusin Dubber

176 posts · joined Jun 2005 ·

#463116
The reason there is not many rotaries in hillclimb competition is due to the miultiplication factor for the engine and specifically, the OUTPUT is not competitive. The only reason there is a multiplication factor has more to do with assumed capacity to enable class setting and therefore parity rather than swept capacity. I should qualify that, parity is only relative - if you are being beaten then you get the shits, if you are winning it is all good. Anyway, it has always been pie in the sky stuff when it comes to reaslisticly establishing the assumed capacity of the rotary engine. For example, differently ported engines will have a differrent capacity, yet still compete in the same class. Hows that possible????? A 12A engine has a displacement of only 550cc per rotor, and the engine fires 3 times per revolution of the eccentric shaft (crank). And to follow a bridge port or Perripheral Port (PP) engine has a far larger swept capacity than a standard port engine. The reason for this is the bridge port has a large brow cut into the end plate enabling more air - and hence more cc into the combustion chamber, the PP has the water jacket punched to allow injection straight into the chamber. The swept capacity and horsepower increases but the physical displacement is constant. Confused, so is CAMS.

Its never been fair so why now should it be any different.

At least now my RX2 will be a little more competitive.
To live and love is a gift, to video tape it and get caught is stupidity

tassupervee That really hurts doesnt it!

1,171 posts · joined Sep 2003 ·

#463256
Umm.... I think you will find tha the rotors effective 'swept" capacity does not vary. The porting arrangements you speak of simply vary the volumetric efficiency of the given swept volume.
The analogy is to alter the port timing of a 2 stroke or the cam profile of a 4 stroke. Doesnt change squat in swept volume but alters volumetric efficiency (cylinder filling) enormously.

Above all, thats part of the the fun of running an engine configuration that is NOT "internal conbustion reciprocating engine"

Its the same for 2 stroke versus 4 stroke GP bikes and so-on. That experiment was tried and failed along with 500cc 4 cylinder and 2 cylinder engines.
Everything will always be subject to and compromised by "parity" and no matter what figure you factor in, the bottom line is that it (rotors) are an entirely different configuration of engine and no-one will ever be happy with whatever compromise as far as parity is put forward. It will never be "fair" It really is like comparing apples to oranges.
Sad, but a fact of life for rotor blasters like yourself. Dun get me wrong. I like rotors but they really only compare with...well.....other rotors.

Your only hope for true(ish) parity is to only race with other rotors of the same capacity.
Harsh, but reality!.

L8tr
E
Im not a complete idiot, quite a few parts are missing....