Jez13

They contribute but they are not a combustion chamber by themselves.

If your page one is correct - but it isnt: The term “stroke” in this context refers to how many times the crankshaft or eccentric shaft makes a piston go up or down to complete the cycle or for a rotory to go around and around. Let’s sum this up in a simple chart to visually explain how this works: 2 stroke engine (up, down) – 1 complete crankshaft revolution. 4 stroke engine (up, down, up, down) – 2 complete crankshaft revolutions. 6 stroke (rotary) engine (up, down, up, down, up, down) – 3 complete crankshaft (eccentric shaft) revolutions.

Correct Gary your comming around. And that small part is located just inside the exhaust port at the bottom left of the rotory housing. Ha! A mobile combustion champer? We dont call the surface of a piston the combustion chamber and we dont call the ceiling of the bore a combustion chamber, its the space thats in-between the piston and the bore cieling that makes the combustion chamber. And that space is located on a rotor in the bottom left hand corner of the rotor housing.

LOL. We just have to keep on pushin! Choo choo!

But its not 4 strokes per combustion its only 2 on a rotory. And if it where a 3.9ltr it would be a six stroke.

yup, and that folk thinks that a combustion cycle of a rotor is 6 total combustions rather than 2. I like the formula, I just don't like the values he is using.

But for every 2.6ltrs makes two shaft revolutions, not one.

And that short statement there is why I find it hard to budge my opinion. The rotor only combusts in the bottom left side of the rotor housing so that makes it the only combustion chamber in the engine x that by two and you get your 1308cc.

For the record please try and keep your 'retarded' comments to yourself, this is a friendly discusion on peoples view points and we keep things mature here, i respect and listen to what you have to say and i expect the same from you. The main perspective problem here is you are breaking one single rotor into 3 seperate parts. Answer this: if a 13b rotory's full cylce was determined after one combustion from each rotor - how much exhuast would have been expelled through the exhuast port? It is the same position, if i took a photo of a rotor after one combustion and then took another photo after the second combustion they would be identical photos because they are in the same position. Correct, if you beleive that a rotories cycle is after three combustions. But incorrect if you beleive that a rotories cycle is after one combustion. Because 1 rotor is doing three things at once an one piston is only doing one thing at one time you cannot compare. If one piston combusts once in each cycle then why can't 1 rotor combust once in each of its cycles? Displacement is definative. I am not arguing that the rotory holds 3.9l of air though its rotation, I am arguing that it only uses 1.3l per combustion cycle. If you were a car company and you were told that you can't have any more than 206kw and you had to be competitive with all the other high performance vehicles...what would you do? Its a different kettle of fish. If they wanted to lie about its displacement then why wouldn't they lie about its petrol consumption? You know I was thinking about this some more and came up with a whole new perspective that can have truth to it also. If I were to see a rotories cycle being dertermined after 3 combustions of a single rotor then really it would be a 6 stroke? Remeber it turns the crank 3 times after 3 combustions of one rotor. So basically this whole arguement has come down to determining a rotories cycle. And that is where it may come down to matter of opinion and to what people find is more logical given the evidence.

Yes it is, but you can't use piston formulas on it to decipher its capacity.

Yeah, every other piston engine.

But what if, in Mazda's view that 1.3L is the truth. What if all those highly intelligent engineers that create our Japanese cars came to the conclusion that a 13B rotory is in fact a 1.3l engine. If that is the conclusion then nobody is lying or deceiving. I can understand why it is a 1.3L and connot be a 3.9L - not my fault that others can't.

Weren't you the one who was comparing a 6 cylinder piston engine with a rotory? And now you say you can't compare because they are completely different which was my whole point from the start... Another way to visualise my perspective is to try and imagine that the rotor is just one giant angled face instead of breaking it down into 3 faces (or 3 cylinders in your mind). And that would make you understand that one rotor combusts 3 times in a cycle and turns the crank/e-shaft 3 times with it. Thus producing 1.3l per crank shaft cycle and combustion cycle. If a piston where to do that it would intake 3.9l of air but only use 1.3L of air per cycle (its impossible to do but its for perspective purposes only).

Because your comparing a piston engine again. Each piston makes one combustion per cylinder where a rotory makes 3 per rotor.

No I dont want to compare a 6 cylinder piston engine to a rotory because the piston engine gets combustions and outlets from six different places at different times. A rotory has only has 2 outlets (ports). They are not suitable for comparison. This guy here explains it: He explains that 3 combustion cycles make 3 turns of the e/shaft. Not one cycle for 3 turns of the e/shaft.

So rb20 and 26 are the same but 25 is different? I have a 26 installed from an r33 gtr in my 32 gtr so it should work right? If an rb26 sensor from a 32 and a 33 are the same....unless I have a twin turbo 4wd rb25 with an rb26 cover...oh shit.

There is one reason why I feel we cant apply the same logic. This is because one rotor holds 3 (4) chambers of air but only combusts one at a time, so it only expels 1.3l of air/exhaust per combustion. One piston holds the same amount of air and combusts that same amount of air per cycle. The rotor holds 3.9l of air but only combusts 1.3l per combustion (1:1 as opposed to 3:1).

I was wondering when you were going to post doof - your name has been sitting down there for weeks. I figured you left your computer with this page open and then went on a holiday to hawaii. This discussion went mainly wrong from the start because we were trying to compare the mechanics of a rotory to a piston engine. The problem is they are so different that all the principles related to pistons are different for a rotory. Like how you would class an RPM or what would determine a full cycle for a rotory engine. If you look at how a piston works and then apply it to a rotory you will not find the correct answer. You need to start your mind with a clean slate on the rotory - thats why I feel that my perception is more accurate because I learnt how a rotory works before I learnt how a piston works.

Its not a 3.9L. Yes it can take 3.9L of air but it only combusts 1.3l per cycle. Thats if I convince the public that a cycle is made per combustion and not once the same rotor face has completed a full revolution.

Why does it have to be the same rotor face if after one combustion its in exactly the same position? It doesnt matter that its a different rotor face because it ends up in the same state.

I know how. Just dont focus a full combustion cycle on one rotor face. Refer to my last comment.

What if the rotor was a hexagon? Who cares. Measure the cycle of the e/shaft and the crankshaft returning to is original position. Funny though because the rotor has three equal sides so when one combustion completes it becomes in its exact original postition only its not with the original rotor face. I think thats enough to fill the definition "returns to its original state". Just because its not the same rotor face doesnt mean it hasn't returned to its original position.

With every combustion the output shaft completes one cycle. SK has been trippling his numbers because it takes 3.9l of air for the first side of the rotor to return to its origional position (the other 2 sides following afterwards). If we measure the cycles by full turns of the e/shaft then 1.3l is correct.

I think it makes perfect sense to measure rpms by the essentric shaft, just like pistons measure theirs by the crank. The e/shaft is the rotories equivalent of a crank shaft so the comparison is perfect. Who cares what is going on to make the shaft spin at that speed, it doesn't matter if its a windmill or a hampster on a bicycle - it should get measured where it counts. There is obviously just a difference in opinions on where rpms should be measured but lets face it, a rotor is not the same as a piston but both their primary objectives is to turn the driveshaft.

Gary - in the voice of the kid who said - why cant we have a flat bottom on a taco: why cant we measure cpm from the crankshaft? dadadddaaadda ddaaddda