rx72c I must have setup the minimums to trigger a DTC but didn't setup the actual engine protections. Thank you for the information. I am tip toeing due to my past experiences. I am tuning with the injection unplugged for now but do have the output configured in the ECU. I also have stepped the nozzle from a 500cc down to a 250cc. Is the timing I have too conservative?

Thank you

 

I think it's too conservative but there is nothing wrong with playing it safe if that is what you want to do.

Will be interesting to see how it goes once Shawn is back to finish.

 

Update:
Car still runs and drives but I am noticing that the EGTs are starting to deviate. This began right around 1072 miles.

Looks like the RAs are going downhill again. Thinking about going oem to stop the BS

 

Sadface....

"I said it before and I will say it again.

You guys are not bending apex seals cause you have an issue with the car.
The apex seals are just crap.

Put OEM in it and you won't have an issue again."

-rx72c

 

Just curious here, how do deviating EGTs (assuming you baselined what your "normal" EGTs are) relate to your apparent conclusion that the RA apex seals are going downhill? I would think deviations in "normal" EGT readings would be more due to issues with tuning (i.e., fueling or spark timing out of whack). Did you compression test the engine after observing the deviated EGTs?

 

Pete, I have done a compression test since seeing the deviation and the rear is down to high 80s average while the front is in the 100s.

With all things being the same in the tune and the only difference being the deviation it is clear the compression is falling/changing for the worse.

I might just try and drive it for a little bit to at least enjoy it a little. I'm not sure if it's just shitty seals but when I do go through this rebuild ringer again I'm going to get new rotors and housings and OEM seals.
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Have you got additional fuel trimmed to the rear rotor?

Are you still running OMP, if so flow tested?

Hoping I can avoid this when I eventually get mine back together the I-rotary seals.

 

" I would think deviations in "normal" EGT readings would be more due to issues with tuning (i.e., fueling or spark timing out of whack)." i agree w Pete. most probable is something in the fueling or timing. while i would never run RA seals i don't think they are your problem.

i do agree that OE seals are a breed apart BUT they do easily break at the tip if you have detonation. if you could guaranteed as to running detonation free i would run them but i don't see any guarantees available.

first move here is to look at the plugs.

 

Slides, I do not have additional fuel trimmed to the rear but am running the car quite rich to alleviate any lean concerns. Better to have the front rotor rich then the rear lean.

Not running omp Premixing 2 oz per gallon Redline Full Synth

 

Howard,

Pulling plugs didn't show much to my eyes, I did just recently swap a new set in to try and get a better read but I don't have any drag strips in my area to test. The rear rotor was not showing the orange color as before. The porcelain was very similarly colored to the front. The only visible difference in the plugs was ever so slightly more carbon build up on the rear one. Still running the r7420-10. I would be happy to share my timing/fuel maps with you to get your opinion.

 

are you running any different timing between the front and rear? send your maps to howracer@gmail.com

 

If RA SuperSeals are failing, it's the tune or something mechanical. This is what someone would say if they do their tuning based on arbitrary numbers instead of reading spark plugs.

Factory Apex Seals will wipe anything out in their path when something does fail, versus simply a quick engine rebuild. Say goodbye to your turbo, exhaust, exhaust port, muffler, etc.

ONE is approved for an airplane to get you back safely an event of failure. The other holds zero compression and would kill you if you relied on it.

 

you should read the whole thread, and tally up the facts. this is 3.

 

Jeff, without being rude, I was solely focused on the apex seal and not trying to blame the obvious external factors.

On Michael's initial tuning on Aderptronic, ignition sync was off or that tuner is an idiot. You can hear and see clear as day. Either that or it was ONLY running on trailing ignition plugs.

Then there are engine build issues which I won't fault anyone for. They may not notice an apex seal tip having blowby is due to the slot of the rotor being unequally pinched or untrue.


Bad.

Bad.


Okay, but not perfect.
This line should be crisp and even width.


Perfect Apex Seal Slot.


Now, it's still a tuning issue.
It's still a building issue.

It's not an Apex Seal Issue.

 

Gucci,

Thank you so much for the information provided I think it is a great addition to the thread. Please note that these are RA classic seals and not the black super seals. I would whole heartedly agree that there is builder error. I am the builder and I sure do like to make errors! The tough part is finding some trust worthy to build me something that just works or teach me all the secrets. Until then it seems I'll keep trying/learning.

How would an uneven rotor groove cause this sort of failure? Would a brand new pair of rotors measure properly out of the box?

​​​​

 

Sent the logs there is no timing difference between rotors

 

they don't easily break. That is absolute rubbish.

I have exploded them at 1000HP and it took a significant repeated lean outs to do it. Any bendy seal would have been dead in the water on the slightest lean out.

 

Any Mild Steel seal won't take out a turbo or anything post-exhaust port.

Factory Apex Seals when they go, will disintegrate and wipe out anything in their path.

Makes that simple motor rebuild turn into a motor rebuild + turbo + exhaust. Line your pockets...

Here's the thing that needs to be said on this. Omar, you are blaming a non-factor item to the failure of Michael's builds. It's not the Apex Seal.

Clear as ******* day, you can hear the original tuning on that Adaptronic sound bad on video, and immediately glow the exhaust manifold.

NEW Factory Apex Seals with a "RaceOnly" laser etch to them are still going to fail with age. Any new seal will be better than something 10+yrs old with hundreds of heat cycles. It's best to simply advise that a motor is gone through properly, despite compression numbers as AGE is what results in factory seals failing, not the overall material selection.

So when I advise someone to run an aftermarket seal that matches their usage, I'd rather see them get home after driving to a circuit event vs. towing their car back 8hrs. Rotor Housings are wear items. Add Premix and Add Seals that Bend, so you never leave someone stranded.

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Here we go. Ryan go to bed buddy.

 

You are so caught up in entitlement and disliking me that you can't seem to take the time to be helpful for others.

It's a darn shame. I really wish the best for you.

Michael, there are great engine builders out there to send the block to and resolve things mechanically.

I haven't heard a more recent video of how the car is running, but if you post something similar to your first video, we can identify if tuning is still an issue.

 

rotor housings are not supposed to be wear items, what are you talking about (ok, maybe if you are a mazda race team)? On a piston engine, is the block with cylinder bores also a wear item (again, I’m talking typical use case here, I don’t think we’ll see this car at 24hr lemans any time soon)?

also, we are not flying planes here, your whole analogy of not having to tow broken a car home from the track it’s insane. Why not build an engine that doesn’t fail so frequently so that’s not the first thing you are planning for? Those seals flying in planes do not take anywhere near the abuse a track car will create, they fly at almost constant rpm and are not pushed anywhere near the limit in order to be highly reliable. Has anyone here been on a plane powered by a rotary where the seals failed but made it out alive because they were bendy?

 

Cylinder Honing happens for every rebuild... What backyard junk engine building are you doing?! Of course the housings are wear items!

It's not about happening frequently, it's about for when it DOES happen that the person driving isn't endangered more than they have to be.

By all means, you advise people how you wish to. I'm telling you what makes sense for engineering factors of safety on engine design. We aren't dealing with opinions; these are metallurgic facts.

 

All,

The factory seals have been researched by Mazda for many decades. They are built for reliability and longevity at lower power than we all want. The choice of apex seal will still be hotly debated for years to come.

There must be a mechanical or a tuning related issue that is causing the seals to fail .

Mechanical possibilities are that the apex seal slot is not properly clearanced (rx72c) which can cause the seal to pinch in the groove, or not move as freely. This lack of movement may put more pressure on the housing surface and more friction heat into the seal itself (My reasoning). This though would show as a score in the housing I would think. Other mechanical possibilities would be a weak ignition but I have 4 brand new IGN1A coils and very good wiring to them. Still scratching my head on the mechanical possibilites...

Tuning issue possibilities are endless technically. The first one that comes to mind though is that my trigger is somehow offset incorrectly. I did use the FFE wheel which only bolts on one way, but it does not line up with the factory marks on my pulley. The only idea i have at the moment would be to set the timing based on the pulley marks and not the actual trigger wheel tdc mark. That though is scary and could lead to more damage. Mabye ill check TDC with the flywheel flat side just to make sure, but it is hard to be confident.

 

To add to the apex seal information this is a cool read:

https://patents.google.com/patent/US3802927

Some people say OEM seals are steel. It seems they are cast iron

 

the one Ryan is alluding to, is that the seals seal to the housing, but also they seal to the side of the apex seal groove. just like a piston ring seals to the cylinder wall AND the top (or bottom) of the piston ring groove