Why Do Rotaries Suck?

[DRD-00F]

I say you should average it because for the other 2/3 of the time the engine isn't going to be a 7 litre and isn't going to be performing as such either. Let's hypothetically stretch out your example for the sake of explaining why we would do this. Imagine two chambers have 2L each and one chamber had a very hypothetical 200L...will this engine perform like a 204L rotary all the time? Or will the other two chambers compromise the 200L combustion chamber to produce performance more on par with an average rather than a sum...say 68 litres? That is why we would average it. You can't just sum it because not all chambers are combusting at the same time...and only an average will account for time.

Do you mean to say that the rotary has the same inputs and outputs as a piston engine? The very things that I said are the only things you can compare a piston to a rotary using? This is fascinating because I said this about 30 pages ago. The rest of the engine is different...incidentally, this includes the in betweens (supposedly the most important part of how an engine works)...the very place where displacement is derived from...and it is different.

A 6 cylinder isn't firing all its cylinders at the same time either, why do we wait til they are all done in a piston engine, but divide it in the rotary engine? Surely some kind of even and fair middle ground, one that was already in place CEMENTER IN HISTORY for several years would have been a better way to go about things then to make up your own way of doing it. And don't say it's cause the rotary is so different, we've proved more then once that it can and does fit into the same boundaries as piston engines.

Yes it does have the same inputs and outputs. Is this the only thing you can compare? NO! what about compression? what about ignition? spark plugs? fuel? oil? rotational power? Like I said, the engines are very similar. They take the same stuff in, use the same process to gain power, then throw the same stuff out and finish with the same result. Why, if it is doing so much the same, is it such an impossibilty to compare HOW MUCH of the stuff gets put in?

Reply to bold bit: So if we can ONLY compare that a rotary and a piston use air and fuel and expell CO2, how does the rotary come about doing such a thing? I know piston engines use the otto cycle, and that can't be the same as to what's in the rotary engines otherwise we could compare them. So, Birds, how does a rotary change air and fuel into CO2 without the otto cycle?

[DRD-00F]

Also Birds, it doesn't matter if a 204L engine performs like a rocket ship or a tonka truck, it's still a 204L engine. Performance has variables that aren't defined by the engine.

[Sydneykid]

They are the key words mate..."the same way we measure every other style of Otto cycle engine". The rotary engine came along and defied all this because it couldn't be measured the same.

But it can, and it has. There is nothing different in measuring the capacity of a rotary engine. It pumps and how much it pumps can easily and quickly be measured. The only question is how many degrees and/or rotations do we include in that measurement. Mazda say 1/3rd (1.3 litres for a 13B), but there is no basis for that. Lots of people say 2/3rds (2.6 litres for a 13B) based on eccentric shaft revolutions. I say 3/3rd (3.9 litres for a 13B), based on rotor revolutions.

There is no doubt that 1.3 is wrong, there is an argument for 2.6 but it's not as strong as the argument for 3.9. The argument for 2.6 (based on eccentric shaft revolutions) loses out as soon as the degrees of rotation of a 2 stroke and 4 stroke piston engine are compared.

Science must adapt to the rotary, not the other way around. When you have a vessel that is so different to the norm the same rules don't apply, it's a different game.

There are no new dimensions in a rotary engine, it's a 3 dimensional object and a such can be measured by normal 3 dimensional mathematics. Sure it's an unusual shape but that's irrelevant.

Cheers

Gary

[Smity42]

A 2 stroke piston engine also performs the Otto cycle.

Agreed

So is it one rotor and one combusion chamber or 3 combustion chambers?

Good question, if we could answer that we could settle this capacity debate

If it's one rotor and one combustion chamber then it's a 2 stroke because it does all 4 processes of the Otto cycle in one rotation (orbit if you prefer) just like a 2 stroke piston engine.

If it 3 faces then face isn't a cycle, each of the 3 faces goes through the 4 Otto cycle processes, some of them simultaneously. While one face is compressing, another face is inletting, just like a 2 stroke psiton engine. While one face is inletting another face is exhausting, just like a 2 stroke piston engine.

Please see my other posts on why it ISN'T a 2 stroke. You are getting it towards the end there, it IS LIKE a 2 stroke, but isn't a 2 stroke.

No they don't, to be a 3.9 litre we have to count the 3 faces of the rotor to determin the capacity. If we count the 3 faces then the 2 stroke simultaneous processing can't be ignored.

But, when we measure a 2 stroke, we only measure the part of the chamber that is combusted by the 'ignition' step (ie the top half of the chamber. If we are going to measure all 3 faces of a rotary to count the capacity, shouldn't we do the same for a 2 stroke?

Please note: I still agree with you that 3.9 is MORE accurate, imo. But I can see the other side of the argument.

We are discussion capacity, rpm and stroke/cycle type. The problem with using power and torque is efficiency, and rotaries are very inefficient in comparison with modern piston engines.

Agreed

Doesn't that depend on how many cylinders the 2.6 litre 4 stroke has? You realy only have 2 choices, it's either a 2 cylinder or

a 6 cylinder depending on whether you claim 2 combusion chambers in a rotary or 6.

If you are assuming a 2 cylinder 2.6 litre 4 stroke, then it fires 1 time per crank revolution.

If you are assuming a 6 cylinder 2.6 litre 4 stroke, then it fires 3 times per crank revolution.

As you said 1 or 3 doesn't = 2.

Doesn't that depend on how many cylinders the 1.3 litre 2 stroke has? Once again you realy only have 2 choices, it's either a 2 cylinder or a 6 cylinder depending on whether you claim 2 combusion chambers in a rotary or 6.

If you are assuming a 2 cylinder 1.3 litre 2 stroke, then it fires 2 times per crank revolution.

If you are assuming a 6 cylinder 1.3 litre 2 stroke, then it fires 6 times per crank revolution.

Let me guess, you choose 2 cylinder 1.3 litre 2 stroke. Then you're stuck with that 2 stroke problem again.

Obviously 6 doesn't = 2

Capacity should NEVER depend on the number of 'combustion mediums'. A 6 piston engine with 0.5L per piston is 3L, and a 12 piston engine with 0.25L per piston is 3L.

OK, you got me on this one, what's a 6 stroke? Would that be 6 combustions? In which case yes, I agree. But if you mean 1.5 times the 4 Otto cycle processes then I don't agree. Because is see no basis for 1.5 times anything.

A 6 stroke would be a theoretical piston engine that takes 6 strokes of the piston to complete its thermodynamic cycle. I can't see any way of making this work with an otto cycle, but so what? its a theoretical comparison. And probably the best one if you want to compare a rotary to a piston engine.

Edited October 2, 2009 by Smity42

[Sydneykid]

So is it one rotor and one combustion chamber or 3 combustion chambers?

Good question, if we could answer that we could settle this capacity debate

I always thought this was a no brainer. If we spin the rotor once it fires 3 times, now that’s either a 3 sided piston or 3 combustion chambers. Take your pick, one or the other. The best thing is it doesn’t actually matter when measuring capacity, the important fact is it fires 3 times. Not once. The fact that it fires 3 times means we can’t count just 1 firing to measure the capacity.

So forget the 3 sided piston versus 3 combustion chamber argument, it’s irrelevant when discussing capacity.

Cheers

Gary.

[fuzzy_scuz]

Is this still going?

jeeze some people are so precious about lies.....

lies I tell ya... A rotor is a comp engine like all engines of this type it requires 3 things

fuel

spark

air

if it looks like a duck it is a duck.

if it is a wood duck trying to be a swan, then it is still a duck.

[Birds]

A 6 cylinder isn't firing all its cylinders at the same time either, why do we wait til they are all done in a piston engine, but divide it in the rotary engine? Surely some kind of even and fair middle ground, one that was already in place CEMENTER IN HISTORY for several years would have been a better way to go about things then to make up your own way of doing it. And don't say it's cause the rotary is so different, we've proved more then once that it can and does fit into the same boundaries as piston engines.

Yes it does have the same inputs and outputs. Is this the only thing you can compare? NO! what about compression? what about ignition? spark plugs? fuel? oil? rotational power? Like I said, the engines are very similar. They take the same stuff in, use the same process to gain power, then throw the same stuff out and finish with the same result. Why, if it is doing so much the same, is it such an impossibilty to compare HOW MUCH of the stuff gets put in?

Reply to bold bit: So if we can ONLY compare that a rotary and a piston use air and fuel and expell CO2, how does the rotary come about doing such a thing? I know piston engines use the otto cycle, and that can't be the same as to what's in the rotary engines otherwise we could compare them. So, Birds, how does a rotary change air and fuel into CO2 without the otto cycle?

Because some view a rotor as a single combustion chamber...that's where average comes into play. If a combustion chamber in a piston engine is different to the rest it isn't going to affect the rest of the chambers like it would in a rotary. You make a good point about not doing it for a 6 cylinder piston engine. But this is where I say your rotary with 1.3/1.3/1.4 litre faces is a 1.3 litre engine 2/3 of the time, and a 1.4 litre engine for 1/3 of the time. Variable displacement...welcome to the world of rotaries, you can't use piston science for it. You haven't proved anything...the only boundaries the rotary fits into with piston engines is the inputs and outputs...so I don't see the point of comparing the in betweens / workings of the engine. Compression? Irrelevant...one engine rolls into compression whilst the other pushes evenly with an up/down stroke. Ignition? One uses two spark plugs residing in only one of three chambers...the other engine has a spark plug in each chamber. Oil? They use it in different ways. And rotational power of a crankshaft is an output, not an in between, therefore something you can compare them on. Still think it's fair to compare their innards on the same principles and science of internal combustion based on piston engines? You're taking a piston engine science and tryin to make it work for rotaries...it doesn't.

It's not that they don't use the Otto cycle, it's that they have different methods of attaining it. The otto cycle isn't a methodological process...it's a series of events...how an engine goes about achieving them can differ for sure.

But it can, and it has. There is nothing different in measuring the capacity of a rotary engine. It pumps and how much it pumps can easily and quickly be measured. The only question is how many degrees and/or rotations do we include in that measurement. Mazda say 1/3rd (1.3 litres for a 13B), but there is no basis for that. Lots of people say 2/3rds (2.6 litres for a 13B) based on eccentric shaft revolutions. I say 3/3rd (3.9 litres for a 13B), based on rotor revolutions.

There is no doubt that 1.3 is wrong, there is an argument for 2.6 but it's not as strong as the argument for 3.9. The argument for 2.6 (based on eccentric shaft revolutions) loses out as soon as the degrees of rotation of a 2 stroke and 4 stroke piston engine are compared.

There are no new dimensions in a rotary engine, it's a 3 dimensional object and a such can be measured by normal 3 dimensional mathematics. Sure it's an unusual shape but that's irrelevant.

Yes there is a basis for that...it's called one complete revolution of the eccentric shaft, and in my opinion it counts as a complete cycle and therefore the displacement.

And therein lies the answer...people will never agree on the true capacity of the rotary engine...the rotary is what you want it to be.

[GT-R32]

A 2 stroke piston engine also performs the Otto cycle.

So is it one rotor and one combusion chamber or 3 combustion chambers?

If it's one rotor and one combustion chamber then it's a 2 stroke because it does all 4 processes of the Otto cycle in one rotation (orbit if you prefer) just like a 2 stroke piston engine.

If it 3 faces then face isn't a cycle, each of the 3 faces goes through the 4 Otto cycle processes, some of them simultaneously. While one face is compressing, another face is inletting, just like a 2 stroke psiton engine. While one face is inletting another face is exhausting, just like a 2 stroke piston engine.

Your classifications of four and two stroke are incorrect. Each rotor face performs the Otto cycle in four distinct sections, that's all that matters and you will find just about technical texts agree with me. It's a 4 stroke/cycle engine.

By your logic a multi cylinder 4 stroke engine is 2 stroke because of where each piston is up to in the Otto cycle. LOL! It's flat out wrong Gary.

No they don't, to be a 3.9 litre we have to count the 3 faces of the rotor to determin the capacity. If we count the 3 faces then the 2 stroke simultaneous processing can't be ignored.

What? That a stroke isn't 'wasted' because intake and compression occurs in other parts of the engine? Honestly. There are 4 distinct things happening here. It's a 4 cycle/stroke. Do some more reading and come back.

So what, more relevant is that it fires air/fuel mixture 6 times per revolution of its 2 rotors. Which I see you get to in the next paragraph.

Relevant? Of course it's relevant. It's a FACT.

Doesn't that depend on how many cylinders the 2.6 litre 4 stroke has? You realy only have 2 choices, it's either a 2 cylinder or a 6 cylinder depending on whether you claim 2 combusion chambers in a rotary or 6.

If you are assuming a 2 cylinder 2.6 litre 4 stroke, then it fires 1 time per crank revolution.

If you are assuming a 6 cylinder 2.6 litre 4 stroke, then it fires 3 times per crank revolution.

As you said 1 or 3 doesn't = 2.

Doesn't that depend on how many cylinders the 1.3 litre 2 stroke has? Once again you realy only have 2 choices, it's either a 2 cylinder or a 6 cylinder depending on whether you claim 2 combusion chambers in a rotary or 6.

If you are assuming a 2 cylinder 1.3 litre 2 stroke, then it fires 2 times per crank revolution.

If you are assuming a 6 cylinder 1.3 litre 2 stroke, then it fires 6 times per crank revolution.

Let me guess, you choose 2 cylinder 1.3 litre 2 stroke. Then you're stuck with that 2 stroke problem again.

Obviously 6 doesn't = 2

WTF are you on about? At least you are discussing relatives although it appears you are confused.

The 1.3L 2 stroke equivalent would be a 2 cylinder each of 654cc capacity.

The 2.6L 4 stroke equivalent would be a 4 cylinder each of 654cc capacity.

OK, you got me on this one, what's a 6 stroke? Would that be 6 combustions? In which case yes, I agree. But if you mean 1.5 times the 4 Otto cycle processes then I don't agree. Because is see no basis for 1.5 times anything.

Cheers

Gary

I'm talking equivalents which is particularly difficult for you to understand, we end up going around in circles. I call it a 3.9L Wankel. That's the only correct way to rate the engine, which is the equivalent to the various piston engines as I have already explained dozens of times, which is in accordance to many other bodies that rate the engine... For some reason you are insistent on arguing this point?

The engine is NOT and will never be correctly classified as a 3.9L 2 stroke. You can pretend it's geared 1:1 rotor to output. But it's not. Stop trying to put it into that box.

Let's all say that the RX8 has the following engine to make Gary happy:

3.9L 6 chamber(/cylinder) 3,000RPM rev limited engine making peak power of 170kW @ 2733RPM and max torque of 633NM @ 1833RPM.

But you know what? That isn't true. It's NOT FACT. When the International Engine of the Year was awarded to the RENESIS for the 2.5-3L catagory it was done so with the RENESIS being rated at 2.6L. Why? Because I think those engineers have some idea of relative.

[Birds]

And f*** this "same rotor position, different face" bullshit of the rotary engine...as if it matters! If a piston could somehow flip itself over for the next combustion stroke so that it had a different face for it, would this change how much displacement the engine has? How much air/fuel it's combusting in a cycle? No.

[GT-R32]

And f*** this "same rotor position, different face" bullshit of the rotary engine...as if it matters! If a piston could somehow flip itself over for the next combustion stroke so that it had a different face for it, would this change how much displacement the engine has? How much air/fuel it's combusting in a cycle? No.

Exactly. So calling to a 2 stroke just because it is a design which allows the 4 distinct parts of the Otto cycle occur in different parts of the engine is incorrect. And there is only 1 place where combustion occurs per rotor, just because it conveniently performs 4 separate cycle functions in other areas means shit. It can all be brought to relative using the shaft anyway.

Further my post above, Gary suggest rotaries need a big gearbox because they are a 3.9L as they are now (not true). Well imagine if they were geared 1:1 - if it were possible? This actually demonstrates using Gary's method of rating that they are a high torque (not low as Gary suggests) low revving engine. But they simply aren't, it's not fact and it ignores where torque and power are measured (the output shaft).

[Birds]

I've got another question for the 1.3 doubters...if a rotary could hypothetically cycle and combust in all three chambers at the same time...what would its displacement be? The same 3.9 litres you claim the 13B to be? Or would you want to triple that figure again?

[DRD-00F]

Because some view a rotor as a single combustion chamber...that's where average comes into play. If a combustion chamber in a piston engine is different to the rest it isn't going to affect the rest of the chambers like it would in a rotary. You make a good point about not doing it for a 6 cylinder piston engine. But this is where I say your rotary with 1.3/1.3/1.4 litre faces is a 1.3 litre engine 2/3 of the time, and a 1.4 litre engine for 1/3 of the time. Variable displacement...welcome to the world of rotaries, you can't use piston science for it. You haven't proved anything...the only boundaries the rotary fits into with piston engines is the inputs and outputs...so I don't see the point of comparing the in betweens / workings of the engine. Compression? Irrelevant...one engine rolls into compression whilst the other pushes evenly with an up/down stroke. Ignition? One uses two spark plugs residing in only one of three chambers...the other engine has a spark plug in each chamber. Oil? They use it in different ways. And rotational power of a crankshaft is an output, not an in between, therefore something you can compare them on. Still think it's fair to compare their innards on the same principles and science of internal combustion based on piston engines? You're taking a piston engine science and tryin to make it work for rotaries...it doesn't.

It's not that they don't use the Otto cycle, it's that they have different methods of attaining it. The otto cycle isn't a methodological process...it's a series of events...how an engine goes about achieving them can differ for sure.

I don't care how it affects it while it's running, that comes down to too many variables (fuel type, boost pressure etc) all I care about is how much can fit in the cylinders. Say you bored out 4 of 6 piston chambers and had oversized pistons, would you equate the total amount of air it can hold, or average it? If you say average it, then you're simply wrong. It's not something any mechanic would put into practice.

Displacement is a simple measure of amount. It doesn't waver because the instrument it's in isn't performing that well. Your description of a 204L engine being labeled a 68L engine cause it 'performs like one' is a load of rubbish. So as engines get older, their displacement is automatically decresed comparative to performance?

Instead of this 1.3/1.3/1.4 rotary engine, why not just be simple and say 4.0L? It's like taking a snapshot of an engine and saying that RIGHT NOW it's 1.2L, but if we move the film forward 3 frames, the engine magically turns into a 1.3L!

I'm not using piston science, I'm not a mechanic. I'm using simple logic.

Compression is still compression, it doesn't matter if it's rolled or pushed, they are still forces acting upon maluable matter to decrease the amount of space it has to take up. It's the same.

Ignition is still ignition, it's a spark igniting combusatble substances. Where and how many there are doesn't mean shit. Hence why people can take out 1 of the spark plugs in the rotary. It's the same. And you are clutching at straws with this one.

Again, I'm not taking piston engine science, I'm taking internal combustion science and applying.

To be honest Birds, you are picking out the finest of details... saying compresseing air by pushing it or rolling it is so immensly different that there is no means for comparison, yet the same thing happens to the same stuff to get the same outcome. That's input, action and output. I really don't understand how you think that compressing air in 2 different ways is so different that it's incomparable.

I'm ignoring the fact here that if you were to push a round object, it would roll. Which I shouldn't cause it's proof that sometimes these 2 IMPOSSIBLY DIFFERENT ACTIONS have no choice but to be the same damn thing...

[DRD-00F]

And f*** this "same rotor position, different face" bullshit of the rotary engine...as if it matters! If a piston could somehow flip itself over for the next combustion stroke so that it had a different face for it, would this change how much displacement the engine has? How much air/fuel it's combusting in a cycle? No.

Yes it would, cause the 'cycle' would now be twice as long.

You would have the cycle with the first face, then the cycle with the second face. add them together in a loop and you get ONE FULL CYCLE!

But then of course motorsport would have to DIVIDE to make it FAIR when racing other cars cause this happens in 1440 degrees.

[DRD-00F]

I've got another question for the 1.3 doubters...if a rotary could hypothetically cycle and combust in all three chambers at the same time...what would its displacement be? The same 3.9 litres you claim the 13B to be? Or would you want to triple that figure again?

I've got a better question!

Imagine a plane engine, nice and round. Imagine a 100 face rotor inside a round block, and it does it's awesome orbit/rotation thing, but cause it has 100 faces, there are 100 intakes, 200 spark plugs and 100 exhaust ports! It's moving quite slowly around and around... Quite a feat to imagine, but it could indeed work.

Now, with it's 100 chambers, would this be a 1.3L engine? Would you rate it on a single chamber, or times it by how many there are to get 130Ls?

Or would you be stubborn and just say "It's a 1.3L... but because it's a rotory, let me teach you on how it works and why I now have to state there are 100 chambers... you see, 4 score and 7 years ago..........."

[Birds]

Yes it would, cause the 'cycle' would now be twice as long.

You would have the cycle with the first face, then the cycle with the second face. add them together in a loop and you get ONE FULL CYCLE!

But then of course motorsport would have to DIVIDE to make it FAIR when racing other cars cause this happens in 1440 degrees.

So why would it be unfair? Where is the extra power stroke? All I said was the piston face flips over, like in a rotary...never said anything about another power stroke being there. Truth is it would do nothing for the engine and only supports the idea that a rotary only has one valid combustion chamber per rotor.

[Birds]

I've got a better question!

Imagine a plane engine, nice and round. Imagine a 100 face rotor inside a round block, and it does it's awesome orbit/rotation thing, but cause it has 100 faces, there are 100 intakes, 200 spark plugs and 100 exhaust ports! It's moving quite slowly around and around... Quite a feat to imagine, but it could indeed work.

Now, with it's 100 chambers, would this be a 1.3L engine? Would you rate it on a single chamber, or times it by how many there are to get 130Ls?

Or would you be stubborn and just say "It's a 1.3L... but because it's a rotory, let me teach you on how it works and why I now have to state there are 100 chambers... you see, 4 score and 7 years ago..........."

100 chambers and only 1 of them ignites at any given time because only one of them has a spark plug in there? Yes, it's still a 1.3 litre rotary that takes a long time for the hypothetical rotor to return to it's original rotor face. Give it up Doof, all you do is inadvertently support our case.

[Birds]

I don't care how it affects it while it's running, that comes down to too many variables (fuel type, boost pressure etc) all I care about is how much can fit in the cylinders. Say you bored out 4 of 6 piston chambers and had oversized pistons, would you equate the total amount of air it can hold, or average it? If you say average it, then you're simply wrong. It's not something any mechanic would put into practice.

Displacement is a simple measure of amount. It doesn't waver because the instrument it's in isn't performing that well. Your description of a 204L engine being labeled a 68L engine cause it 'performs like one' is a load of rubbish. So as engines get older, their displacement is automatically decresed comparative to performance?

Instead of this 1.3/1.3/1.4 rotary engine, why not just be simple and say 4.0L? It's like taking a snapshot of an engine and saying that RIGHT NOW it's 1.2L, but if we move the film forward 3 frames, the engine magically turns into a 1.3L!

I'm not using piston science, I'm not a mechanic. I'm using simple logic.

Compression is still compression, it doesn't matter if it's rolled or pushed, they are still forces acting upon maluable matter to decrease the amount of space it has to take up. It's the same.

Ignition is still ignition, it's a spark igniting combusatble substances. Where and how many there are doesn't mean shit. Hence why people can take out 1 of the spark plugs in the rotary. It's the same. And you are clutching at straws with this one.

Again, I'm not taking piston engine science, I'm taking internal combustion science and applying.

To be honest Birds, you are picking out the finest of details... saying compresseing air by pushing it or rolling it is so immensly different that there is no means for comparison, yet the same thing happens to the same stuff to get the same outcome. That's input, action and output. I really don't understand how you think that compressing air in 2 different ways is so different that it's incomparable.

I'm ignoring the fact here that if you were to push a round object, it would roll. Which I shouldn't cause it's proof that sometimes these 2 IMPOSSIBLY DIFFERENT ACTIONS have no choice but to be the same damn thing...

You know what the funny thing is about the writing in bold. That's exactly what it is. Because it's only one part of the engine that's different to the rest. And you want to total it into some aggregated displacement? When total displacement figures assume that displacement is equally shared amongst chambers?

Even if I'm wrong about my averaging, your totalling assumes that the 4 litre is evenly divided amongst combustion chambers...it's not the case. If one chamber has different displacement to the rest then you need to state so...and only for that cycle will it be a 1.4 litre engine...for the other cycles it will be a 1.3 litre engine. This is such a bad hypothetical example anyway, because balanced engines don't work this way.

I don't understand how you think that compressing air in 2 different ways is so similar that it's comparable? What's your point? For my argument the key words are "different ways". How many spark plugs there are does mean something. If you have 0 spark plugs in an engine it won't run, if you have 3 spark plugs in only 3 chambers of a 6 cylinder engine, it will run as a 3 cylinder engine. If you have spark plugs in all cylinders, it will run as a 6 cylinder engine. How can you say that number of spark plugs and where they are located does not affect it? Nothing wrong with looking at these finer details mate, this is afterall, how an engine works...it's not a simple machine, they are complex.

[DRD-00F]

Why the f**k would only one ignite with 200 spark plugs? All 100 would be igniting at the same time, then the massive 100 sided rotor would move on to the next one, take in gas, compress, ignite, expell, repeat. it will have to do that 100 times til it gets back to the first 'ignition chamber'.

I'm not so sure you got that right...

[fuzzy_scuz]

here is a better example

you can keep your 1.3 Rotor

we will change all Piston engines to the following

2 Stroke 2 litre = 1 litre

4 stroke 2 litre = 0.5 litres

6 stroke 2 litre = 0.3 litres

you see piston engines per cyclinder uses less than a rotor......!

[Birds]

Why the f**k would only one ignite with 200 spark plugs? All 100 would be igniting at the same time, then the massive 100 sided rotor would move on to the next one, take in gas, compress, ignite, expell, repeat. it will have to do that 100 times til it gets back to the first 'ignition chamber'.

I'm not so sure you got that right...

I apologise I missed the part of your example where all 100 chambers had spark plugs in all of them...so if they are hypothetically igniting at the same time then yes it's a 130L engine. Remember, I said if hypothetically a 13B rotary could ignite all chambers at once then what would you call the engine? 3.9 litres or 11.7 litres?

Tell me, and here's stretching the limits of hypothetical...but if a rotor had 1000 faces and just as many chambers but only spark plugs in one of those chambers...would it be a 1300 litre engine or a 1.3 litre? Pretty horrible performance for a 1300 litre engine LOL, given it can only ignite ONE CHAMBER AT A TIME.

That's fantastic, your example has actually further proved my point that a rotary only has a valid 1.3 litres of combustible displacement and it's own cycle.