Ive never heard anyone claim that the Classics eat the housings, just the Super Seals. I would have been shocked if you had the Super Seals with that type of mileage.

 

Classics eat housings, back in 2004 I opened a few low mileage engines to see new housings destroyed( 1:1 syn premix ratio too). However I have an engine with 50k miles on it that runs the classics, and is still running fine.

On a side note I had a fuel pressure failure on they dyno yesterday @ 24psi, ALS seals survived. Engine is still running strong.

 

Isn't it amazing what a rotary engine can endure, yet still run and make power? Some of the terrible things, wear marks, and worn out components I have seen on teardown is nuts. I know every other rotary shop has seen this too. But a lot of these crappy bastards still fire up and make respectable power. A piston engine with cylinder walls torn up like that would not run! Pretty crazy little engines.

 

I think in part is its because of its simple design. it takes less effort to spin something in a circle rather than to push down on an object that has to reciprocate rather than follow its own momentum.

 

If you can get them to start(assuming no broken seals) they always seem to make good power as long as the turbos and other components are in good order. My last personal fd was to this day, the fastest stock twin fd I have ever ridden in. Compression was in the mid to low 90s and hot starts werent the quickest but it pulled like crazy.

It was running RA Super Seals, admittedly they took a beating of 15-16 psi regularly on stock injectors/93 octane with water meth. However, the compression peaked very quickly and consistently dropped over the 6-7k miles I put on it before selling the car as a roller.

 

I have the NRS 1pc gray seals and IRP build the engine. At the time, it was when NRS first introduced the seals? So far, so good. But I do understand that when the seals go, it will take out everything in its path. My rule of thumb is analyzing what ErnieT and Roan run. What I want to see is billet rotors being implemented though. When stock rotors take detonation, they have the dimples after. I can imagine billet rotors being more detonation friendly. What ever happened to them, it seems billet rotors just fell off the map!

 

I think the reason is because the price far exceeded the power gains and reliability at this time. And lets face it, 99% of rotary owners are cheap bastards. lol

 

Yea that 1st batch of classics were junk. Mine were the 2nd run seals. Were all these damaged housings FD housings? Curious maybe the RA seals are better suited to the older chrome style (S5 prior) housings? These seals may wear completely different between the two housing surfaces. I mean there has to be a logical reason why some housings wear faster than others with RA seals.

 

I purchased Classic a few months ago. I’m going to be self tuning and want to make sure they will hold, then I will replace them with Mazda seals once the tune is perfect.

Has anyone run Classics with an OMP Adapter? Different oil (two stroke) directly into the engine vs. Premix

 

There is a couple of issues with the billet rotors- First and most serious is they are too light to the point that you lose the "flywheel effect" which drops your torque right off the chart.
Fairly sure titanium alloy rotors were done at some point, but there are problems thaere as well, not so much with the machining, but with the initial casting/forging process then the coatings that would need to be involved to keep them from galling everything in sight. Obviously the tooling alone would be pricey along with the R&D involved to determine tolerances etc. We used to joke about the $10K titamium rotors, but that really has a lot of truth to it.
If billet rotors were made out of a "heavy" aluminum and not machined to be ultra light you might have something that was really durable and would still perform as you wanted it to. Ov course your now talking $4-5k a set, but ya gotta pay to play.

 

Please don't take this personally, but i've read this a few times on this forum recently and would like to address it here.

You can't just replace apex seals like you'd replace a catback exhaust, or a water pump.

I'm an engine builder with a shop, and would in theory be the 'ideal candidate' for such a task.... if it wasn't a completely horrible idea

What happens when someone actually goes through with this lunacy, and then their 'perfect tune' gets thrown off by a bad tank of gas, or an overboost on a cold night?

A typical 'tune' is not static, there are many variables that affect it. This proposal is flawed on numerous levels..... if a customer came to me and wanted to do this (and pay me twice) I'd refuse.

Do it once, do it right. If you're going to run RA seals, then make sure you premix and go about your day.

 

What he said! Also, do not forget that the OEM seals will reguire additional brek-in time etc. that needs to be accounted for.
The only time I have heard of people running one seal first and then swapping out seals is when the Cermet housings are used. Apparently they eat OEM/Atkins etc seals like they are going out of style. Pineapple told me that unless the user is going with ceramic seals, he now "breaks in" the housings using a set of OEM Mazda seals then swaps in a second set after some number of hours on the engine. The first set "burnishes", for lack of a better description, the Cermet surface which sacrifices the first set of seals yet allows the second set of apex seals to then seat in and live a long time.

Otherwise, one set of seals per build please

 

If you are using this "method" so that you can "tune" your own car, then you really shouldn't be "tuning" anything. And to tell yourself that by doing what you're planing on doing, you will somehow "save" your engine from detonation/failure is extremely false thinking and ignorant on your part. I mean, YOU are the one who wants to build your engine twice because YOU'RE trying to"tune" it... And you don't see a problem with this???
-J

 

The weight of the rotors, just like the flywheel, has no effect on the engines torque output. That is rotational inertia you are referencing, not torque. Lighter rotors would not cause a drop-off in torque at all and may in fact increase the torque output (though I am not 100% of this as I have not seen it happen in person). This would be due to the fact that the energy required to spin the e-shaft is more efficiently transmitted through a lighter rotor.

For drag racers, they use a heavier flywheel to help with launch to prevent bogging etc while road racers use a lighter flywheel for maximum engine responsiveness to help with braking, matching rpms etc.

 

What are you talking about and where are you getting your "information" from? First of all, your "theory" on loss of torque is false. Second of all, they already have billet aluminum rotors, and have for years (@ a price of 5k per set "pre clearances" with seals). And feuds what? They weigh not even a half a pound less then t2 rotors do.

-J

 

I am talking about a specific instance where a known car ran very fast on "OEM" rotors, dropped in aluminum rotors, car made virtually the same horsepower on the dyno. Went to the track, car ran almost a second slower. Reason? Couldn't get out of the hole.
Aluminum rotors are not the key, especially if you need torque. If they were, Mazda would have done them in the 787 and Downing would have done them in the Kudzu's. They did not, even with a virtually unlimited budget.
You need the flywheel effect to help generate the torque, but believe what you want.

 

Alright thanks that’s why I’m asking the questions now before I start anything. =] I have access to a machine shop and all the tools I need to its not the same as an average Do It yourselfer.

You said make sure I Premix, but I was going to run a custom OMP adapter to pump two stroke oil because after searching and reading I feel that it offers better oil distribution and consist than premix. Would you agree?

 

I understand what you are saying but it is due to rotational inertia, not torque. Simple physics. The inertia of a heavy flywheel (your flywheel effect) is advantageous for standing starts with drag cars as that inertia, not torque, is used to help get the car going.

Play catch with a nerf football and then with a bowling ball. The energy that knocks you on your *** when catching a bowling ball is called inertia, not torque. Same principle applies to flywheels. To further illustrate this, you can even put the ***** on a string and play tether ball with them and have the same effect, all the while the same principles apply. Things in motion tend to saty in motion etc. etc.

The lower weight of the rotors can be countered by a heavier flywheel to achieve the same thing as with stock rotors. There are downsides to this for some applications such as road racing due to the fact that the engine takes longer to wind up and wind down.

Btw, what known car are you talking about that ran a second slower?
You stated the hp was the same after the rotor swap so then what was the torque rating?

That is rubbish and not the reason Mazda or Downing didn't use aluminum rotors. There would be a multitude of other reasons they didn't use them, least of which for the reason you stated. On that note, where do you get your info?

LOL, flywheels don't generate torque. If that were true in your argument, so would the clutch, pressure plate, driveshaft and wheels, brake rotors and even the lug nuts. None of these things produce energy.

Physics lesson for you:
All the energy is produced by the engine while the latter things just spin behind it. Energy cannot be created or destroyed, only transformed. The levers on the e-shaft generate all the torque (energy) as transfered energy from the combustion process. The e-shaft spins everything else and the gears multiply torque. The energy that is stored in the aforementioned spinning parts is called inertia, in particular rotational inertia, and they will resist outside forces acting upon them due to the conservation of angular momentum. This is what helps drag racers get out of the hole better with a heavier flywheel. Pretty simple, huh?

I'll continue to believe what I want, which btw, are the laws of physics.

 

on point ....The rotary engine relies on its overall rotating mass as enertia//torque combo..there is a limit on how much weight you can remove from the rotating mass before you dump the clutch and and see the dragon out your throttle body.

 

It's not on point and it misses the point completely.

 

Believe what I want??? Look at the crap you just wrote... so let me get this straight, he who has the biggest flywheel makes the most torque, no matter the engine size and output huh? Are you absolutely sure that the flywheel isn't in place to keep up the inertia between combustion cycles? And that is the reason why engines like v10s, v12s and 4 rotors hardly need any "flywheel" at all, because the combustion processes are happening so often giving the engine a smoother more free abuilty to rev through the rpm range. Give me a break.

Maybe Mazda should have hired you, with your 100lb flywheel and your 50lb rotors, then they wouldn't have had to deal with all that sequential tt bullshit in order for them to extract maximum low end torque out of the FD... I mean ****, your way is much cheaper and easier!

I guess when you put a lightened rotating assembly and a 4.5" clutch and flywheel on a 4 rotor it doesn't make the engine performe better because of its ability to make power more freely through the rpm range, it instead robs it of torque? Because hey, we all know that the faster your engine has a "free" a willingness to rev through the rpm range, the less torque and power it'll make... sheeesh.

Also, on the contrary, I know of a 13b that PICKED UP HP and trq, with the ONLY difference being the switch from cast iron rotors to billet aluminum ones. But I guess that's impossible huh? If you don't believe me why don't you do some research on a red datson 1200 with the first ever set of billet rotors from E&J...

-J

 

It is on point. I understand exactly how the rotary engine works, and why it does, or does not, make power.
There are obviously other things at work as well such as compression ratios, timing, port timing, etc. that have an effect.
Also, I do not believe you understand the actual physics of how an engine works. Doesnt matter how many pages of material I write or examples I use I doubt you will come to understand the reality of the situation. Thats fine.

Oh, and I cannot reveal which race car used those rotors and went slower, as I am probably not supposed to even know about it.

I WILL tell you that I was not kidding about Titanium rotors and them being 10K, and I know of several reasons aluminum rotors for road race cars was abandoned, among them the lack of torque to drive out of the corners. Lesson for you- corner exit speed is the MOST important thing to have in a race car. Faster out of the corner, faster down the straight, faster lap times. Those of us that have raced a momentum car understand exactly how this works.

 

Are you done now?

 

I disagree with this. There's nothing wrong with him taking the necessary precautions. Any mistakes he makes wont cost him a complete rebuild by using the RA's 1st. After he gets comfortable tuning then he can switch seals if he chooses. I would take the exact same approach because I like leanring and doing stuff myself. You can't learn anything always paying someone else. Then your at that persons mercy when you need to change something (not me). DIY'ers don't mind pulling their engines apart from time to time. Hell I've put together a usable o-ring kit so I can break my engine down whenever I want (and have done so 3 times last year already for experimenting reasons).

 

Did I say you needed 45lb rotors? No, I said that too light a rotor and you lose the ability to get out of the hole- in otherwords low-end power or torque. This has been PROVEN. Argue all you want, but your not correct in your ASSumption.

Cheaper? Where did I say anything about cheaper? I said there was issues with them, and we both know they are. Why are you argueing the point? We both know what happens when you put a 7.5lb flywheel on a car, if you dont, the back up until you do know. I HAVE driven multiple cars with carbon/carbon 5" Tiltons, and they suck to get moving. In fact, they were so light the engine would stall at lift throttle on corner entry. In that case it was a trade off between getting the highest RPM possible out of the motor and sacrificing a bit of pull on corner exit. Once the RPM level was regulated down and the gearbox limited to specific ratios, the 5" clutches went away.

We both know the sacrifices made there, dont try and play a card you dont have. a 4.5" clutch on a 4 rotor is only possible because of the increased rotational mass of the 4 rotors, in other words the flywheel EFFECT- reading- its fundemental! Try it with a 2 rotor- I dare you.

Well, HP can be gained for a variety of reasons. If you know as much as you think then you know EXACTLY which car I mentioned above, and you know they are now back on OEM rotors, and you know why they are back on them.
I also believe the first ever set of E&J rotors were not quite as light as others they made ofter, although I could be wrong. I actually looked into the rotors, and asked people who are using them, so I am not talking out of my *** or off what I read on the internet. Obviously for road racing and not drag racing, but the reasons are still the same.

Have you ever driven an EPROD car with a 12A with the cut to hell rotors? you cant get it moving and corner exit is all about maintaining momentum, because if you slow down at all, its over for you.