Sydneykid

2 strokes, one up and one down Think Otto cycle, after all it's a combustion engine. It a 4 part cycle, a 4 stroke/cycle engine does each of the 4 individually. Whereas a 2 stroke/cycle engine doesn't, it combines parts of the cycle, it does them simultaneously. Just like a rotary. So is it a one cycle because of one revolution of the rotor? Or because of one cycle of the eccentric shaft? Be careful, if you say it's one cycle of the rotor then you admit the rpm lie and the capacity lie, but support the argument on cycles. If you say it's one cycle of the eccentic shaft then you admit the capacity lie and the 2 stroke/cycle, but support the rpm lie. Your choice. Cheers Gary

We have domne this before, how many 2 stroke/cycle charateristics do you want? Inlets and exhausts at the same time Fires every rotation/orbit/cycle of each combustion face of the rotor Inlets every rotation/orbit/cycle of each combustion face of the rotor Exhaust every rotation/orbit/cycle of each combustion face of the rotor Has no valves, the rotor opens and closes the inlet and exhaust ports Oil in the petrol There isn't one thing that the rotor does that is a unique 4 stroke characteristic. Why not, we do it with a 2 stroke piston engine. Even that doesn't work, because a rotor has 3 sides and a 2 stroke piston only 2. So we would have to look at 2/3rds. Exactly, that's why we don't count crankshaft revoltions in a piston engine, but you want to count eccentric shaft revolutions in a rotary engine. You see your problem? Every rotary argument you raise has consequences elsewhere in the package of Mazda lies. You can't be correct with 1 without killing the other 2 arguments Cheers Gary

No, but in a roary engine the majority of the combustion chamber is the rotor. In a piston engine the minority of the combustion chamber is the piston Not always the case though, in a diesel engine often they have a flat head with the combusion chamber (bowl) in the piston. So a rotary is not unique in having a moving combustion chamber. Irrelevant, the piston crown is involved in inlet, compression and exhaust, but we still include it in the term combustion chamber. Cheers Gary

Same as a 2 stroke piston engine, one cycle of the piston. A 4 stroke piston engine takes 2 cycles of the piston. Cheers Gary

Nope Oh my, you really don't know the anatomy of a rotary engine all that well, best you pop back to the diagram of how a rotary really engine works What it is, is what it is. And in a rotary engine that space rotates (orbits if you prefer) with the rotor. No it's not, even by your flawed definition it's not. Cheers Gary

Here's where the rotary guys lose the battle; You can't claim it has only one combustion chamber and at the same time it's not a 2 stroke, it inlets at the same time as it exhausts. Everybody knows that 4 strokes don't do that, only a 2 stroke does. If you claim it has 3 combustion chambers to avoid the 2 stroke evidence, then you can't claim it is 1.3 litres You can't claim it's a 6 stroke and then only count 1/3rd of it's combustion processes to determin capacity. You can't use eccentric shaft degrees to determin a rotary engine's capacity and then refuse to use cranckshaft degrees to determin a 4 stroke piston engine's capaciity When you isolate an individual lie about a rotary engine (capacity, rpm or stoke/cycle) and use specifics and narrow definitions to support that lie, you lose the other arguments. Use all of the evidence and apply all of it to the 3 questions and you end up with only one conclusion, 3.9 litre 2 stroke rotary engine where the rotors only do 3,000 rpm. Cheers Gary

My turn, but a rotary doesn't stroke. Since we are quoting thread history, it's a 3.9 litre 2 stroke/cycle engine. Shall we go back to page 1 and start again? Cheers Gary

That doesn't stop Mazda from stating the true capacity The depeends on the definition of combustion chamber. Obviously a chamber has more than one side and in a rotary engine the part of the combustion chamber that is stationary, the housing, is the smaller part. The vast majority of the combustion chamber is in fact made up by the 3 sides of the rotor and the combustion bowls cast into each one of those 3 sides. So in a rotary engine the majority of the combustion chamber rotates with the rotor. Hence it really has 3 combustion chambers. You can’t call the entire rotor housing the combustion chamber because it also contains inlet, compression and exhaust processes. Only one part if it, the minority, is involved in the combustion part of the cycle. Cheers Gary

Then compare that with a 2.6 litre 4 stroke piston engine. The same, 2 revolutions of the crankshaft, but we don't call it a 1.3 litre. Cheers Gary

No we haven't, that's why Mazdas doesn't run at LeMans anymore, a fight over true capacity. That's why there were no rotaries in F1 in the 70's, a fight over true capacity. Thats's why motorsport authorities world wide apply multipliers to Mazda's stated capacity. So whether or not "this person" wanted it classified correctly or not isn't important, the fact is plenty of organisations, important ones, do. Their not worried because they know it's 4.0 litre engine with a turbo. The 4.0 litre capacity is on the front guard of Fords. Why do Ford bother making a badge and puting on the front guard? Because capacity is relevant to their buyers. They are not being lied to. Ford doesn't say it's a 2 litre engine, because it only fires every second revolution of the crankshaft. It's 4.0 litre and Ford promote it as such. If capacity was as irrelevant as you would have us believe then Ford would save some money delete all engine capacity badges and not promote them, That's the important point, they all state the true capacity and then qualify it with whether it's a diesel or turbocharged or supercharged or intercooleed or maybe all of the above. In all cases, but one, the starting point is the true capacity of the engine. It's where the basis starts, then the qualifiers are added. Except in one case, Mazda modify the capacity first, then add the qualifiers. My point is Mazda should say "3.9 litre rotary engine", because that's what it is. Even if you subscibe to the 1080 versus 760 degrees of shaft rotation theory then Mazda should say "2.6 litre rotary engine". But they don't and that's why I object and why I call it a lie. If, as you claim, capacity is "somewhat irrelevant" then why shouldn't/didn't Mazda state the true capacity? The answer is obvious, Mazda obviously consider it relevant and that makes your opinion irrelevant. Cheers Gary

A combustion engine is an air pump, we measure capacity by how much it pumps. The same as we measure oil pumps, water pumps, fuel pumps, diesel pumps etc, basially any type of pump you can name is rated by its pumping capacity. Except one, a rotary engine is not measured by how much it pumps by Mazda. If you count the eccentric shaft revolutions as being relevant than a 13B pumps 2.6 litres. If, like me, you think rotor revolutions (orbits if you prefer) is more correct then a 13B is 3.9 litres. There is no way of measurng pumping capacity that comes up with 1.3 ltres for a 13B, none, zero, zilch, diddly squat, effall. What the vast majority of people agree is that Mazdas 1.3 litres is a lie, the discussion is about whether they lied and it's really 2.6 litres or 3.9 litres. Cheers Gary

You're comparing a cylinder with a rotary chamber. When the truth is they are nothing alike, physically or dynamically. A piston in that cylinder has only one combustion face, a rotor has 3 combustion faces. Cheers Gary

To me it's black and white, a rotary is a combustion engine, Otto cycle if you prefer. All other combustion engines, every single one of them, are measured the same way. Piston port, 2 stroke, 4 stroke, diesel, petrol, 2 valves, 4 valves, 5 valves, pushrod, SOHC, DOHC etc etc they are all measured exactly the same way. Regardless of efficiency or number of revolutions of the crank/eccentric shaft. There is only one that isn't and that's wrong. You say Mazda should be allowed to get away with it becuase they say its "1.3 litre rotary engine", the "rotary" qualifier means they can use whatever measuring stick they like. But if anyone else tried the "1.3 litre 4 stroke" or "1.8 litre diesel" when it was really a 2.6 litre you'd be screaming blue murder. You say it's OK to understate the engine's true capacity by a factor of 3, because everyone knows its really a 3.9 litre. When the truth is not everyone knows, this thread is living proof of that. If everyone knew then it would have stopped at page 1. I have plenty more ways of explaining why 1.3 litres is wrong, using any termninology you care to dream up. You can muddy the water all you like, I know what the bottom of the river looks like and I can clear it up so everyone else can see it too. Cheers Gary

The mathematics of exactly why 1.8 times was chosen, instead of say 1.9 or 1.7 or leaving it at 2, no I don't know. It was a bit of a closed shop back then, that secret boys club stuff is why there was a big spill in the CAMS board, new president etc. I don't recall an official communication on it, there was some discussion that it may have been pushed due to improvemetns in piston engine efficiency in the previous 25 years compared to virtuallty static rotary rotary efficiency. If we knew that for a fact, which we don't, then a counter argument could be made based on Renesis development. In simple terms, there has been rotary development, put it back to 2 times. Personally 1.8 or 2.0 is irrlevant as it is simply a multiplier of a number that is incorrect anyway. ie; 2.0 X wrong = wrong. Never expressed it as 0.59, let me check, 1.3 x 1.8 = 2.35 / 3.9 = 0.59. Yep, the maths works, but I have idea what 0.59 means. Is there some signifiicance to 0.59? I know that it was reduced from 2 times in the mid 90's, I can't remember the exact year, I'd have to check my CAMS Manuals. Different food chain back then. I know that it's now 1.8 times, but only in Australia, it is different elsewhere. A turbo petrol engine is 1.7 times and a turbo diesel will be 1.5 times when CAMS approves my recommendation on it. Cheers Gary

But they don't, the firing order has a large efect on the sound. That's why a Ford V8 doesn't sound the same as Chevy V8. Obviously a V6 doesn't sound anything like a I6. A Renesis engine, because of its port layout, sounds quite different. The number/time of combustion/exhaust events also influences the sound of an engine a lot. We have a V8 SuperCar engine Windsor (5 litre) that has had a longer stroke crank fitted (6 litres) which means slightly higher gudgeon pin height in the pistons. Everything else is exactly the same, but the sound is very different. Even the same engine can sound quite different, say a VTEC Honda on the low lift short duration camshaft lobes, it sounds completely different on the high lift long duration lobes. Cheers Gary

OK, so a Mini (BMC not BMW) engine has siamesed exhaust ports for it centre 2 cyliders ie; 3 exhaust ports for 4 cylinders. That means we should only count 75% of it's capacity. But we don't. A rotary engine takes 3 turns of it's eccentric shaft and Mazds divide it by 3. A 4 stroke piston engine takes 2 turns of its crankshaft, so we should dived its capacity by 2. But we don't. Cheers Gary

The problem with your examples is that in each of them the engine manufacturer is quoting the actual capacity of the engine, a 1.3 litre 4 stroke piston engine is called a 1.3 litre, a 3 litre 2 stroke petrol engine is called a 3 litre, a 4.2 litre diesel engine is called a 4.2 litre. That capacity is measured by how much they pump in one complete cycle of their combustion media. Except one, Mazda call a 3.9 litre rotary engine a 1.3 litre. Yes of course there are differences in how an engine performs depending on it's type, diesel, petrol 2 stroke or 4 stroke and that why the engine manufactuer tells us what type of engine it is, so we know what to expect. But they don't lie about the actual capacity, they don't halve it cause it's a 4 stroke, they don't double it cause it's a 2 stoke. But not Mazda, they divide the actual capacity by 3. I don't believe that I am being pedantic in believing that all engines should state their true capacity. Cheers Gary

Oh so now we use effeicieny to determine an engine's capacity. So if I have a 3.9 litre 6 that a bit tired and only pumps 70% I get to call it a 2.7 litre. That's makes a lot of sense, so if I build sloppy engines with poor pumping efficiency I get to run in a lower capacity class. We both know that's not how it works, it's still a 3.9 litre engine no matter how efficient or ineficient it is and that's what it classified as. Using your logic a Renesis engine should have a larger capacity rating as it is more efficient. Cheers Gary

Say what? Let's apply the same logic to a a 3.9 litre 6 cilinder piston engine. It has 6 chambers of air but only combusts one at a time, so it only expels 650 cc of air/exhaust per combustion. So we should call it a 650 cc engine, I don't think so. If you want to do the comparion the 3.9 litre 6 cilinder piston engine will need 2 revolutions of its cranksahft to expel 3.9 litres of air/exhaust. While a 3.9 litre 6 chamber rotary engine will need 3 revolutions of its eccentric shaft to expel 3.9 litres of air/exhaust We don't dived the 3.9 litre 6 cilinder piston engine's capacity by 2, so why should we divide a 3.9 litre 6 chamber rotary engine's capacity by 3? Any way you look at it it's wrong, it's illogical, it's inconsistent and it's a flat out lie to cal a a 3.9 litre 6 chamber rotary engine a 1.3 litre rotary engine. Cheers Gary

A current generation, say Honda F20 or K20 are close to 90% brand new and after run in around 93%. As a comparison for a race engine, a V8SuperCar engine (pushrod V8) is ~96% as measured on the engine dyno after run in. Cheers Gary

This is a Nissan ball joint, note that it has a dust cover and yes it is full of grease. Nissan warranty their ball joints for 100,000 k's, they expect it to last at least that long because it has a seal to keep the dust out and the grease in. On a race car I would, and do, use exposed (no dust shield) spherical bearings. Yes, we do meticulously clean them after every race. But we still replace them frequently because they wear out very fast when exposed to dust, dirt, grit, water and sand etc even for a very short time. If you don't mind the cost in time and money doing that, then by all means run your sphericals exposed. Cheers Gary

So you think everybody who believes Mazda's claim of 1.3 litres for a 13B is an "ignorant fellow"? That's a bit harsh isn't it? Personally I believe that some people actually believe that Mazda wouldn't lie, hence the 1.3 litres must be right. They're not ignorant, just tricked by the Mazda marketing spin. All I am trying to do is open their eyes to the possibility that maybe they have been conned. If you want to call me a "pedantic bastard" for exposing them to the truth, then so be it. Cheers Gary

Done it, the ariflow meter reads around 3.1 litres, that being 3.9 litres at around 80% efficiency. Cheers Gary

I don't know exactly how the 1.8 times was calculated. I do know it used to be to be 2 times some years ago. But the ACO (the organisers of the LeMans 24 Hour) rejected the 2 times multiplier as not being enough, that's why no rotaries running there any more. So even the motorsport regulators of the world can't agree on a multiplier. Whilst they don't agree on a multiplier it is unanimous that the Mazda quoted 1.3 litres for a 13B is wrong as a comparitor. The argument is really all about how wrong it is. The 1.3 litre lie was exposed long ago. Cheers Gary

Mazda (they are the manufacturer) quotes 1.3 litres for a 13B, they don't multiply it by anything. Cheers Gary