sleeperRX7

i have a subsription but i dont really have the time to read all the articles, its about 4 moths old i think, it said something about mazda lying about the actual size of our rotary engines, like a 13b is actually a 2.6b if measured by the standards every other engine is measured by? im a little confused? it said a 12a is actually a 2.3a

i know rotary engines are in know way related to a piston engine except they burn fuel and oxygen to create combustion, but why would mazda measure them a totally different way, are they afraid if they said a 13b was actually 2.6 liters that the public would think rotaries make no power and a (1.6 liter vtec honda engine with 127 hp.....example) would mean there pointless and becasue of there gas milage and so on and not so friendly reliability (sometimes).

basically what i mean is since they say they are only 1.3 liters, are they wanting people to think that that small size and power gets our attention. even if a 13b was called a 2.6 b its still to me the best engine designed, 3 moving parts, Three. whats your opinion? does anyone have the article to post?

Nemesis

Not this again....

4RotorRocket

I heard that also in Super Street I think or was that in Sport Compact Car.I get both monthly so if I find that article I will post it up right away.I wonder what mazdas answer would be on that.

-=RX-7 KID=-

It all depends on how you take the mesurements of the engine for all purposes the rotary is a 1.3 liter it's just when iot moves it becomes a 2.6 because we fire 3 times per cycle insted of 1. I think that's why. Someone ask dragon he will know.

vancouverrx7

i believe i came across this discussion with a friend who had an s2k and it goes something like this.



for every 1 full cycle the pistons have, we have 2. If you think about it, we have 2 of the 3 chambers ready for combustion per cycle. compare that with the monotonic motion of the piston. so for every 1 cycle the pistons make, we essentially have 2. Ideologically speaking, this should be more effective given the cyclic motion of the rotors versus the loss in momentum energy in the piston design; however, we run into a thermodynamic problem because the heat from the combusion chamber in the RE causes the engine to heat up decreasing the ratio of engine temp vs combustion temp. In the piston engine system they can keep their engines much cooler than ours, so they can achieve higher efficiencies by keeping a large engine temp vs combustion temp ratio.



Going back to the question if we measured it in the conventional piston way, our engines are really 2.6 for 13B or 2.4ish for 12A. However, given that the chamber is only 650 or so cc and 1.6L engines are really total size of their chambers, mazda smudged the lines when reporting the size of the rotary engine.



So... if i'm wrong, anyone, please feel free to correct me.

vancouverrx7

ops, i didn't proof read my post before i posted it...



I have a correction to make.



1.) contrary to how it sounds, i'm not saying we make 2 cycles per their 1. I am saying we have 2 chambers ready for combustion while they only have 1. Hence the time it takes for them to complete their cycle and fire again, we have already complete 2 power strokes.



2.) the math in my second paragraph didn't really quite add up. When I say 650cc it is per "chamber." Now we have 2 rotors or 2 rotor housings, hence we have the 1.3L rotary engine. versus say a 4 cyliner 1.6L engine. with a 400 cc per chamber.



once agian, if i am wrong, somebody please correct me.

FrestyleFC3S

i like hats

rotarychainsaw

I thought it was because piston motors are rated 2x there real displacement.

Swervedriver

I thought it was because there's at least 2 10 page+ threads on every car forum in existence that entails this same debate to no satisfying end!



I stabbed a 26" Red in the head last night. Only decent Red I've seen all year.

j9fd3s

a piston engine will fire its rated displacement in 2 revolutions of the crank. a rotary fires is rated displacement in one revolution



mike