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xornr89-

I hope you've gotten the idea of what the difference between 2- and 4-stroke is, by now. To answer your question of cc's and strokes.....

"cc" - is the size of the engine, i.e. 200cc < 500cc < 1500cc; with the same type of engine tuning and "strokes", a larger displacement (cc) will be more powerful; however, don't be fooled by size alone, different types of engines make different types of power, i.e. my SV 650 is a 645cc v-twin and it is considerably slower than a 599cc GSX-R....

"strokes" - is what everyone has said....

slimcolo wrote:Don't believe the Nortons ever made it to NA. Primarily used for Police in UK.

Also used as a factory racer: (Isle of Man TT, and British Formula 1)

http://www.motorbike-search-engine.co.u ... orton.html


It also mentions the first Norton Wankel race bike was made using a cannibalized police bike.

CC is aprox. 0.061 cubic inches. Stroke is the up and down movement of the piston. Displacement is area of bore X stroke X # of cyl.

So for example I'll use the new Revtec 4X4. Four inch bore, four inch stroke, two cyl. (3.149((2)(2)))(4)(2)=104.8 cubic inches, 104.8/.061=1718cc

So Johnj, on that Miller do you calculate displacement of entire motor or just one bank?

How would I know? I do, however, know how to Google.

slimcolo wrote:CC is aprox. 0.061 cubic inches. Stroke is the up and down movement of the piston. Displacement is area of bore X stroke X # of cyl.

So for example I'll use the new Revtec 4X4. Four inch bore, four inch stroke, two cyl. (3.149((2)(2)))(4)(2)=104.8 cubic inches, 104.8/.061=1718cc

So Johnj, on that Miller do you calculate displacement of entire motor or just one bank?

Wikipedia:

"There are various methods of calculating the engine displacement of a Wankel; the Japanese regulations calculating displacements for engine ratings calculate on the basis of the volume displacement of one rotor flank only.

In the most popular Mazda family of engines, the 13B, this consists of two rotors displacing approximately 650 cc (cubic centimeters) each per rotor flank, a total of approximately 1300 cc or 1.3 l (liters)."

So, I guess that generally the displacement is measured by calculating the volume displaced by the change in volume in a single "compartment" times the number of rotors.

Don't the rotor configuration make each rotor have three chambers?

slimcolo wrote:Don't the rotor configuration make each rotor have three chambers?

Yes.

Fast Eddy B wrote:

slimcolo wrote:Don't believe the Nortons ever made it to NA. Primarily used for Police in UK.

Also used as a factory racer: (Isle of Man TT, and British Formula 1)

http://www.motorbike-search-engine.co.u ... orton.html


It also mentions the first Norton Wankel race bike was made using a cannibalized police bike.

Wow, thanks for posting that page, this quote was a real thought provoker

"The engine was rated a 588cc, 1176cc or 1764cc depending on what method you used to calculate it. Naturally Norton claimed it was 588cc, the international race body, the FIM, compomised and rated it 1176cc, which kept it out of most races but our ACU allowed it to race in events under their control as a 588cc engine. Later the FIM changed their ruling to regard the Norton as a 999.6cc as from 1989, which made it eligible for more events. Until race engines are rated on power output or fuel consumption or both, the future of the Wankel enine is uncertain."

If the rules do ever get changed, prehaps we'll see the return of this beast

Nibblet99 wrote: "The engine was rated a 588cc, 1176cc or 1764cc depending on what method you used to calculate it. "

Later the FIM changed their ruling to regard the Norton as a 999.6cc as from 1989, which made it eligible for more events. Until race engines are rated on power output or fuel consumption or both, the future of the Wankel enine is uncertain."

I tried to find a source to explain this disagreement in measuring displacement, but no luck. The best and shortest way I can explain it is this:

The Wankel rotary engine acts like a two-stroke reciprocating engine in that it produces one act of combustion for every turn of its output shaft. Therefore, it produces one act of combustion per intake dispacement, in effect, X2 compared to a fourstroke engine, therefore 588cc X2= 1176cc.

I can see no rationale for measuring a Wankel rotary X3 (588cc X3 = 1764cc. True, there are three combustion chambers per rotor, and the output shaft turns three times per rotor revolution, but the fact remains that combustion strokes occur three times per rotor revolution, once per output shaft revolution (similar to a two stoke).

The rationale for the FIM measuring the Norton rotary as 999.6cc is a mystery to me. I can only guess that the fuel efficiency of the rotary design was taken in to account (as being worse than reciprocating piston engines). I am sifting through FIM's website for technical regulations. The reasoning for these regulations may or may not be included.

Lastly, the 1300cc Mazda rotary is designated just under 2000cc for Japanese tax regulations. This seems to have no technical explanation, more likely to fit into an already existing tax code. I have a feeling the rationale is the same for the FIM's designation.

Interesting? I think so.


**Edit**
FIM search over, no mention specifically of Wankel or rotary engines.

1. Superbike & Supersport World Championship, Superstock Cup do not outlaw two strokes or any other type of engine.
2. GP bikes must run on either a four or two stroke reciprocating piston principal, and MotoGP only on four-stroke.

So okays thanks to Nibblet99 & Sev i perfectly understood what a Stroke is Thanks!
So my next concern is that CC... Hmm okies, somebody has given me a rough description, but can anyone be bothered to explain maybe more precise? Somebody like SEV? =)
I know that he went school~