now then, something ive never really undestood, is this engine sizing bollox?
without getting all complicated, and going into algebraic (spelling?) equasions, explain to me please what exactly the 12b, 13b,and 20b engine sizes are?
why they are called that if its not 1200 cc, 1300cc and 2000 cc?
and why all sorts of people, dvla included come up with what seams like random figures of engine size?
got the engine size thing sussed now, but why on log books are they logged as nearly 3 ltrs??
Join up and we\'ll tell you!
The info is top secret unless you are a member!
Regards
Carl
aw you git
what dya do to become a member, thought i was wheneber i signed up to the forum ages ago?
just found some info that its 654cc per rotor, so whats the dvlas thing all about??
come on tell me PLEASE
ha ha just joined
tell me all i want to know, and dont keep anything from me or else :wave
654cc x 2 rotors = 1308cc. x2 because it displaces twice as much air = 2616cc, I think.
makes sense!
but cc is cubic capacity, if it displaces more air, is this increasing the cc? no its not is it, si how do the dvla manage to record it with bigger cc then?
so whats the difference in injectors, and when should they be upgraded?
ta
just a way of getting more car tax out of us. Some rex owners have there documents showing 1308cc, just the luck of the draw.
so when i plant my rx engine in my beetle, i should be able to still swing it as a 1300, although its tax exempt any way, just thinking insurance, although, dont suppose ill be that lucky :rolleyes:
You will probably get away with it, yes. All depends on who you speek to at the dvla.
No insurance company will see a rotary engine as 1300 - with all that performance, they\'ve done their homework..............
John
Hi James,
Glad to see that you have joined up.
The cc of one rotor chamber is 654cc for a 13b.
There are 2 rotors and in one revolution of the crank (Eccentric shaft) 1308 cc is used for making the power cycle,but in a 4 cylinder 4 stroke engine if power was made by 1308cc in one revolution then it would be infact a 2616cc engine,as two cylinders are not making power during that one revolution of the crank.
Regards
Carl
pah
insurance whats it all about any way??
http://www.mazda.com/history/rotary/e2-1.html
just found on here chamber volume is 672 not 654
everone has somethin different to say :rolleyes:
obvious when explained as well as that,
thanks Carl.
Quote from: jamespah
insurance whats it all about any way??
http://www.mazda.com/history/rotary/e2-1.html
just found on here chamber volume is 672 not 654
everone has somethin different to say :rolleyes:
That is wrong,they have made a mistake.
It is 654cc per chamber on the 13b.
Regards
Carl
i can believe its a mistake, as there is spelling, and misstypes all over the place, quite informative though!
so the carl, how much for a 20b engine then??
and can you explain the different uses of injectors?
please ;)
The cc for injectors is nothing to do with engine size.
20B is a 3 Rotor, so 3 x 654 cc.
i know that but when should you use different injectors?
is it just on turbo applications, or would there be some bennifit using a different size in my 13b n/a??
Quote from: CarlHi James,
Glad to see that you have joined up.
The cc of one rotor chamber is 654cc for a 13b.
There are 2 rotors and in one revolution of the crank (Eccentric shaft) 1308 cc is used for making the power cycle,but in a 4 cylinder 4 stroke engine if power was made by 1308cc in one revolution then it would be infact a 2616cc engine,as two cylinders are not making power during that one revolution of the crank.
Regards
Carl
So, for a normal two-stroke they double the capacity? I don\'t think so.
The swept volume per cycle is the important figure, which is 1308cc. I\'ve had extensive correspondence on this matter with the DVLA and it comes down to the latest legislation governing engine cc for non standard engines.
You used to be able to register RX7s as 1308, as my mate has done, but they seem to have closed the loophole now. The DVLA now, rather arbitrarily, double the capacity of rotary engines. If anyone is particularly interested I can refer them to the exact documents and EU legislation - but I warn you now, it\'s very boring reading!
slider
snif snif
you stink
goodness gracious great balls of fire :cool
Quote from: CarlHi James,
Glad to see that you have joined up.
The cc of one rotor chamber is 654cc for a 13b.
There are 2 rotors and in one revolution of the crank (Eccentric shaft) 1308 cc is used for making the power cycle,but in a 4 cylinder 4 stroke engine if power was made by 1308cc in one revolution then it would be infact a 2616cc engine,as two cylinders are not making power during that one revolution of the crank.
Regards
Carl
That\'s a different way of looking at it and whilst entirely logical and correct, l always thought the size difference was
perpetuated by the FIA in Europe after Rotary\'s started annihilating everything in their small engine capacities classes.
This story if correct would also possibly explain why on Japanese shores the capacities remained pegged at 1300cc !.
The only similar story l have ever heard was with the Skylines when Cosworth Sierras dominated Production saloons and it was deemed to ban them before they even escaped the shores of Japan !!.
Its happened in bike racing too with from memory a certain Road model of Yamaha YZ being deemed a racing machine and therefore being banned in lots of classes before it even got off the production line.
I agree with Carl, was always taught that the cc rating was based on cc used in a single revolution, hence a 13B uses 1308cc per rev, if you were to go on its actual capacity then you are looking at a neat 4ltrs..............
The wankel rotary is a 4 stroke engine.
If you really want to be pedantic about it the "working" engine capacity is 3.924litres ,and before anyone say\'s that is wrong, just think for a moment of how your engine behaves with an apex seal busted,does it run like a 4 cylinder?Of course not,yet there are still 4 chambers left,but with the 2 power pulses per shaft revolution (As in a 4 stroke 4 cylinder piston engine) available it runs like a 6 cylinder when running right,but with longer power strokes has the torque fluctuation of a 6 cylinder piston engine.So for the engine to run right you still need on a 2 rotor engine all 6 of the working chambers intact to operate smoothly.Just because there is one place for the spark plugs does not mean one combustion chamber,there are 3 per rotor,it is just that they move to the one spark plugs location that is all.
I was not saying that 2 stroke engines were measured any differently than 4 stroke piston engines,but there is a rider with 2 strokes,and that is they allways say that they are a 2 stroke engine which tells everyone that they are working twice as many times as a 4 stroke piston engine per revolution.
The rotary really needs to be classified all in it\'s own right.
As for Japanese racing,that is in fact governed by FIA regs from a long time ago,in racing they are not 1308cc.they are infact increased.
All racing is really governed by this.
But the point is,and many will not like this,the rotary is small in physical suize,but larger in capacity than even Mazda would like to admit,it is a useful marketing ploy to say that it is only 1308cc.
The comparison to a 4 cylinder 4 stroke piston engine is the only way to compare the 2 rotor engine due to them both having the same number of power pulses per output shaft revolution.Do the math.
Regards
Carl
Very interesting read, my car was imported earlier this, regestered and taxed as a 1308cc car, shame I can\'t insure it as one :evillaugh