brappp brappp rotary race bikes

**neil_cb125t** · 5th November 2013, 06:27

Whats the rules with F3 and Rotarys - 1000cc single........?

http://www.youtube.com/watch?v=TeQv60OZuP8&app=desktop

**Fastmark** · 5th November 2013, 07:17

Used to watch the Norton Rotarys at Brands Hatch many years ago, always wondered why they were not developed further cause they were bloody fast.

**willytheekid** · 5th November 2013, 07:24

Fuck yeah!!

I'd love to give that some berrys

...wot a sound!

http://www.youtube.com/watch?v=H2GLtGVBWIc

Cheers for sharing neil

**quickbuck** · 5th November 2013, 12:44

Originally Posted by neil_cb125t

Whats the rules with F3 and Rotarys - 1000cc single........?

http://www.youtube.com/watch?v=TeQv60OZuP8&app=desktop

Hmmm, awesome bike...
Trouble with working out the displacement of a Rotory is that it is very complex... And at the end of the day even a "Single" is in fact a Tripple.... For each Revolution there are 3 firing events.
For cars a Factor of 2 was given to them to make them comparible to a piston engine...
Hence a 13B = 2.6L.. A very thursty one at that though....

So the 700cc single here is in fact a tripple... and freaken fast as the pistons don't have to stop and change direction....

One of the machinists wanted to make a 50cc one for the Mopedathon.
I said if he could build any size rotory and fit it in a 50's frame and make it last 6 hours I wouldn't pull it apart to measure it...

**pritch** · 5th November 2013, 12:55

Originally Posted by quickbuck

For cars a Factor of 2 was given to them to make them comparible to a piston engine...
Hence a 13B = 2.6L.. A very thursty one at that though....

I always felt that was something of a bum rap. There would not have been many cars in those days that could cruise at over 160kph and give better fuel economy than the Mazda. It was the amount of spark plugs the little beast chewed through that bothered me more. And yes, I was using the expensive ones.

So to bring this back on topic, I wouldn't want a rotary engined bike unless I had shares in a spark plug company...

**quickbuck** · 5th November 2013, 16:26

Meh... 2-stroke owners know how that goes re plugs don't they 😉

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**Drew** · 5th November 2013, 16:43

It's a piece of piss to measure the displacement of a rotor. The argument starts when you consider how many times per crank revolution that it actually displaces it.

If each side of the rotor displaces 100cc, the engine's displacement is...wait for it....100cc. Is a 500cc single four banger, classed as a 250 because of how many times it fires per revolution? No.

Better yet, can I call my RF a 450 too? F3 here I fucken come baby! Look out Neil, RF gonna steam roll right over your bike on the straights!

And the argument continues from there.

Displacement of the rotor is a fixed number, spinning it three times faster than the crank....open to interpretation.

**quickbuck** · 5th November 2013, 17:17

Okay Drew... Fair point. Wrote that while rather busy.... But yeah you have highlighted the issue...

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**koba** · 5th November 2013, 18:38

It's in the rules.

There is a cc multiplier.

I think it might be displacement in CC's x2.

I'll see if I can find it...

**koba** · 5th November 2013, 18:39

This is the general rule:

10.15.2 Rotary combustion (Wankel Patent): Capacity of one working chamber in
cubic centimetres, multiplied by number of rotors, multiplied by two.

Class rules would need to be considered too.

(500cc rotary for f3 if it fits all the other rules, might fall over on mentions of 'production' but the word 'primarily' might squeak it through)

**koba** · 5th November 2013, 18:48

I quite like this vid:

http://www.youtube.com/watch?v=kBg86bjr8l0

**Erelyes** · 5th November 2013, 19:05

'Sounds that make you jizz'

**SWERVE** · 5th November 2013, 21:10

Originally Posted by koba

I quite like this vid:

http://www.youtube.com/watch?v=kBg86bjr8l0

Thanks for that video link

I was there on the infield at end of Revitt Straight......... the sound of those two coming over the brow of the hill will always stay with me.

**BuzzardNZ** · 5th November 2013, 21:48

Originally Posted by koba

I quite like this vid:

http://www.youtube.com/watch?v=kBg86bjr8l0

+1 That was a good one.

**neil_cb125t** · 7th November 2013, 09:13

Originally Posted by koba

This is the general rule:

10.15.2 Rotary combustion (Wankel Patent): Capacity of one working chamber in
cubic centimetres, multiplied by number of rotors, multiplied by two.

Class rules would need to be considered too.

(500cc rotary for f3 if it fits all the other rules, might fall over on mentions of 'production' but the word 'primarily' might squeak it through)

Oh yep so we need to find a 10b rotary and cut it in half.....