Scalliwag

They have both a chassis and an engine dyno

rzograbian

how would these seals be for use on a single turbo FD

rzograbian

anyone????

RETed

Why not?
Mazda OEM part numbers for apex seals are the same for all FC3S and FD3S application.



-Ted

Scalliwag

Well Ken ran tried the Rotary Aviation seals in one of his race motors and here are the results. Keep in mind that this is the EXACT same way he dynos all his motors using stock Mazda seals.
Using the engine dyno at Rotary Performance the motor failed on the second pull.
The exhaust temps were normal as well as all readings when it failed.
The motor had virtually no compression.

Ken brought the motor home and pulled it apart. The seals were heat discolored and extremely worn. Fortunately the housings were not damaged.
To recap Ken runs NA on alcohol. His best time is in the 10.20's. He has built and tore down his motors hundreds of times and placed 2nd in NHRA All-Motor class last year.
So he is not a novice builder.

I had contacted Rotary Aviation prior to Ken trying these seals and indicated that this motor sees 13k RPM's.
Laura Crooks responded that they have not received any reports of failure at this point.
Brian Cain had great results with Tony Farkas single turbo bridgeported FC.
So reviews are mixed. I am not sure if the high RPM's is what made the difference or not.

Once I take pics of the seals and scan the dyno slip I am sending the results to Laura. I know they are not going to warrant the seals under this application but I wonder whether they will share the info so others will know that there has indeed been at least one severe and rapid failure with these seals.
Unless someone can come forward and say that they have a high RPM motor that had different results it will be very difficult to diagnose because Ken saw all he wants to see of the RA seals.
Of course since I was the one that told him about them and the feedback I have been hearing it leaves me feeling pretty shitty about it.
I am just glad that the only damage was to the seals.
Of course he is not mad at me (or he does not seem to be ) because he knows I gave him advice from what I had read and heard from others as well as RA. That is still a bad feeling though

88IntegraLS

Outch! Assuming this monster 13k rpm engine didn't use the facory OMP, was there any premix in that alcohol fuel mix?

Scalliwag

It was not something that obvious unfortunately. He used the exact same setup as with every other engine so that it was a perfect testbed. He didn't change anything up just to be certain he did not get erroneous finding whether pro or con.
Now whether or not extra oiling (more than what has ever been needed for stock seals) would have helped is anybody's guess I suppose.

scathcart

I've had a set see 9400 on an over-rev (not my car) under forced induction, with 120:1 premix and a 4:1 ratio of 94 octane with tolulene (98 octane), under nitrous.

Compression hasn't been retested, but the engine still runs.

I wonder if alcohol is making the difference?

Scalliwag

I am hoping this is a fluke or it is a problem that will only happen at really high RPM's or motors with no break-in allowance. Since Ken is the only person I know that has made them fail he is also the only person I know running that high an RPM also.

I still would not mind trying some myself because I am not planning on running them like Ken did.
But if these do turn out to fail at high RPM it needs to be known.
To me I would really like to find out that this is not a very likely occurence. The price is great, unless you happen to be Ken Scheeper's

Donn Hecht

Sorry but I got to disagree here. It all comes down to tuning. Ive seen motors that put out some serious numbers as far as RWHP is concerned, wheter it be 2MM or 3MM Apex Seals, it comes down tuning. If there is enough fuel, spark, and the intake temperatures are cool then you shouldnt have any problems. I personally have a daily driven Turbo II in which I managed to squeeze a little over 200,000 miles, which translates to 200,000 hard driven, but well maintained miles (NO B.S.)

OKRX-7

Could it also be possible that not having a break in period could effect the durability of the seals. I realize that the housings were probably as good as could be. But I would think there would be some serious stress put on the seals pushing them at 13k on thier second pull without a break in.

RETed

Unless these guys are going to putting disclaimers on their apex seals, they are all bullshit.

That pretty much puts the nail on the proverbial coffin on all these aftermarket apex seals.  STOCK OEM MAZDA apex seals have been used on racings engines for years with no stupid warping problems.  I think it's safe to say Mazda did their homework on their apex seal design, and these other vendors are trying to get cheap trying to undercut the rising price of the Mazda apex seals.  It's all biting them in the *** now.

I remember the big hubbub about the Hurley apex seals, cause they were under $200 for a set of 6; this was attractive when Mazda apex seals was easily $300 for a set of 6!  Then all the bad news came in.  Hurley is labelled CRAP for those making big power.

Now Atkins threw their hat in the ring.  Read another thread in this forum (try search), and someone was told by Atkins that their seals were not meant to be used over 15psi.  WTF???

Now these Rotary Aviations seals had a big question mark.  Sure, they were used over the normal operation limits for a daily driven vehicle, but it still shows the STOCK OEM MAZDA stuff rox ur nads.



-Ted

Project84

Note to self:

Do not use alcohol as fuel.
Do not rev above 13,000 RPMs.

Scalliwag

Well if you want to be the fastest naturally aspirated rotary you will be.
It would be at this time anyway to say that if you do want to do this you better not run the RA seals.
Hell Ken has gone two seasons now running alcohol and 13k and these "super seals" failed whereas the Mazda OEM's have held up.
We were hoping for a better seal and these have proven at least in this application to be inferior to what he has ran.
A look at last seasons NHRA Import All Motor class times show that Ken has had success with alcohol at high revs.
These seals just failed to give him an extra edge that we hoped for.

OKRX-7

Thats great and all, but if there are seals out there that will hold as long as OEM Mazda under resonable stress and cost a few hundred less I can make that sacrifice... I, unlike the above, am not running alcohol at 13k RPM's...

Scalliwag

Right, if they hold up under different circumstances that is great. We just know where not to use them. Ken is the only person I know that made a set fail.

Project84

I am not competing in NHRA Import All Motor class, hence my note to self. I agree with OKRX-7, if these seals are suitable for the conditions that occur during regular driving or amatuer racing like drag racing, autoX, roadcourses, etc.. then the money saved is worth the sacrifice of not being able to rev past 10 thousand RPMs. People have posted that they haven't had problems under forced induction, and one person so far has had no problems with nitous oxide. I don't think the reputation of the product or its developers should be deminished because it has been determind that the product will fail under such exteme conditions as you described. Not to discredit you or Mr. Ken; I'll cheer for a Alcohol burning rotary all day long and you guys' involvement in the sport at the level you're on is commendable, but the fact is, most of us can only afford to buy alcohol by the 12 pack, not by the tank full. These seals are more economically appealing to the wallet, and thus far, have been proven to be reliable under the conditions they were intended to be used for.

Scalliwag

When I contacted them I told them that Ken ran alcohol and 13k and they had confidence they would hold up. I am just hoping that once I get pics and send them to RA that they do not recommend the seals for a high RPM motor unless they are proven to holdup by someone else maybe.
But since I did contact them prior it is not like we went into this blindly. They thought they would work.

But I really think at least until now they probably never been ran like that and since they held better than most if not all seals on other apps they assumed they would hold up here as well.
Just keep in mind that this is just the follow up to my original post.
I had hoped like hell they would hold up to this and only Ken is more disappointed than me. But that does not mean they are junk, just not as indestructable as some of us thought.
The lack of people reporting failures speaks very highly.

OKRX-7

Did all the seals fail, or was it just one that failed horribly? Also was there detonation at the time of failure? There is so many variables involved in the setup that Ken is running that its hard to pinpoint the failure. Most likely the seals didn't fail, something else in the equation lead up to thier failure. The seals are pretty much the weakest link in the Rotory setup, which isn't really a bad thing, better to replace them than the housing. But as I said, there isn't anything that stands out in the manufacturing of the seals that would make them more prone to failing at high rpms w/ alco injection that all the rest of them have figured out and they haven't. You have to remember that the initial plan for the seals are not for the kinds of abuse that our cars dish out, but that of a plane, sustained hi-rpm speeds. Have you talked with RA about getting a replacement set of seals to test again. I am sure in thier failure they would be willing to do something.

But all my opinion of course.

Kyle

Scalliwag

According to Ken they are all heavily heat discolored and worn. The motor wasn't detonating and since it was on Rotary Performance's engine dyno they have the data printout and the exhaust gas temps were normal and everything looked the same as in all the successful dyno pulls in the past.
He said there was almost no compression on either chamber.
I haven't contacted RA yet because I want to get pics of them. As far as getting a replacement set Ken would not be willing to take the risk this close to the start of the season and as fast as these failed.

Once I have the pics and the data readings I will post them as well as measurements on the seals.
I doubt he measured them beforehand but Brian Cain has a measurement of a new seal to get an idea.

OKRX-7

Will be interesting to see the pics. Did both rotors fail?

Scalliwag

He had no compression on either rotor but there was no damage thankfully. I am sure he was sweating bullets until he pulled it down and inspected it though
He goes to Cali next week for the start of the season. If track conditions are good tonight he is going to a local 1/8" track so I am going to try to make that.

I am afraid that he won't have time now for much experimenting. Mazda delivered his RX8 so that means he is going to be concentrating a lot on getting it built for next season.
If any of you guys get a chance to go to one of the NHRA Compact events this year stop by the pit and talk to him (as long as he is not at a really busy point )
He's one of the nicest guys you'll ever meet and watching a car launch at 11k is a sight to behold.

Bukwild

I am loading these 3mm seals in my t2 vert in the next week or 2. I will let you guys know whats up.

scathcart

In case BDC doesn't, SDC does:

scathcart

Geez, 1/8"?
"Racing Fans, get prepared! Ken's micro-machine RX-7 can run this track in 10.21 seconds!!!"