apex seal options
 

Im getting my engine rebuilt and i ordered the rotary aviation rebuild kit. After i ordered it i was talking to a friend and he said that the RA apex seals suck and I should get the atkins ones. Has anybody had any problems with the RA ones and should i get the Atkins seals?

BTW i have a S4 TII in a first gen thats going to be taken to the track on occasion. Some of the mods are Haltech E6K, full exhaust, 3rd gen radiator and intercooler,ect.

Sorry bro, but your friend is full o' shit. RA parts are far better than Atkins parts. Most on this board will agree.

-Joe

"Better" is a relative term. For quicker break-in and up to 15psi, Atkins seals are nice pieces and the soft compound is less likely to ruin the entire motor if it blows. The RA seals are hard, require a lengthy break-in and will tear up the housings when blown - but they should take more boost when properly tuned. Build the motor according to it's predicted useage.

For primarily street use, Atkins seals are great pieces.

Up to 15psi on Atkins seals? There's a few Puerto Rican race guys here in DFW who boost well over 40psi with them without any issue. I don't know where this "breaking early" thing came from about these seals but they are superb quality and can withstand just about anything we can dish out at them.

The RA seals have come along way in the past year. I am starting to recommend them as a viable option for my customers as well as the Atkins ones. They do have differing characteristics as Jon has pointed out, but they're a good seal to use as well.

B

has anyone actually broken a RA seal? I have heard that they only warp and that none have broken. therefor no wasted housing. My motor is getting built right now with those seals so im interested in any info.

This is exactly why I described them as "better". They claim the material to be 700% harder than stock seals and I've heard of no cases of a blown seal yet...even in very high boost cars. Atkins is not crap by a long shot, but I have seen a few pictures of Atkins seals that blew out in a very strange way. I think they were on this forum, and it looked like the middle of the seal just let go (caused by detonation I believe). A properly tuned car should never detonate, but I feel that RA seals give you that extra barrier of protection should you detonate for whatever reason. The moral of the story is...NO you do not need to switch out your RA seals for Atkins seals (I even use RA seals myself).

-Joe

Well over 40 PSI? I believe it, but damn! Makes my 12 PSI look puny. Any idea what kinda numbers they make and what turbo they are using?

-Joe

well i used to have some respect for atkins but now im not too sure. i dont think i would want to business with someone who doesnt give their competition the slightest bit of respect. you both sound very defensive. If your product is in fact superior then thats just fine, you dont need to put down RA.

thanks for the reply, im currently dealing with autonomic performance in sacramento and so far they are not making me into a very loyal customer. the johnsift fellow seems to have some personal problems with RA.

You guys sound like a bunch of damn amateurs. Dan's first post was fine, but this is just getting rediculous. Yep...I think I lost all respect. I'll tell you whats bullshit actually...stating that 700% harder apex seals are "physically impossible". Thats 7 times harder. There are alloys out there that are 100 times (yes 10,000%) harder than the material in a Mazda apex seal. How can you say that 700% is impossible? It seems that they are harder judging from the fact that I've never heard a story about a blown RA seal. You know of one? Then post it and back it up with evidence. Otherwise I suggest getting the hell off the boards till you can act as professionals. Till then, you're just damaging your reputation. I for one will never buy Atkins again after reading this thread. I just don't want to have to deal with people like you guys if something goes wrong with my order. RA has been more than nice to me every time I've needed something.

-Joe

Exactly. Typically, when people make personal slams at other people, it's because they've run out of good arguments with any meritorious weight. From business man to business man, please be careful. :) In my opinion, you should stick to the technical arguments comparing your products to theirs and, if there's any real theft or unethical conduct going, then nail it _as long as you have good evidence_.

B

i believe that RA site says 700% more bending strength and 85% harder. just trying to clear up some issues.

I agree with the previous people here. It's one thing to come on a board and type in "don't care junior high" style if you're a junior high student, or maybe an immature high school student. If you're trying to run a business, it really doesn't give a good impression to your customers.

I'll point to Kevin (RotaryResurrection) as a good example of someone who posts here representing a business. When he posts, the posts are well thought out, properly typed, and quite readable. He comes across as quite intelligent, and a very reasonable person to deal with (in email as well). If he has a problem with an individual, it's dealt with in a respectable manner, backed up with evidence. If he has problems with parts, there's almost always clear photos detailing the particular failure, and it's not accusing people of making junk, just wondering what exactly happened.

Corrected into something vaguely approaching written English:
From the RotaryAviation website:
If you're going to argue a point, at least make sure that you're arguing the right point. I see no reason that those numbers are "impossible" to achieve.

Also, regarding the compression test numbers - what were the engine conditions? If you took the compression numbers off the Atkins seals on a broken in engine, swapped in the RA seals & tested right away, I'm not surprised the numbers were low. Throw in a new set of Mazda seals, and the numbers would still be low. The RA seals are known to take a long time to break in - 4000 miles or so is generally a number I've seen thrown around.

Also, when a problem was discovered with the RA seals (they were warping under high boost), the problem was discovered, and exchanges were given to anyone who purchased a set of seals that might have been improperly milled. I consider that a classy move from a business.

Previously, I had no real preference in seals. However, after this thread, I will no longer even be considering Atkins seals in the future.

-=Russ=-

sorry guys but dan atkins had nothing to do with the post i was accidently under his account everything posted till this point was me i relized it after the fact sorry again besides that syonyk and jamesBONG what up guys if u have a problem, and want to help me with my english maybe u should start a new forum www.englishfordummies.com and jay to answer the question about the motor beging brokin in. No the motor was built comperssion tested then torn down only replacing the seals then again comperssion tested

Not true. I did some testing on the some of the earliest RA seals, which are still similar to their current seals. I managed to break one seal, and it did zero damage to the rotor housings... zero.

Here was what was conducted during the test:
I cut the flow of fuel to the secondary injector on the rear rotor at 5000 rpm and 12 psi via a switch in the interior of the car. The car detonated very audibly and then died.
I can only tell you the detonation must have been severe, because it cracked the rear endplate, all of the corner seals, and 5 side seals. The single broekn apex seal lost a chip where the two seals meet, at the corner of the longer piece.
The apex seal stayed in its groove, and the chunk remained in position. No apex seal chunks left the engine.
Rotary Aviation was shocked to hear of it, and has offered to replace the seals for free. I declined, simply b/c its not fair to charge them when I was simply testing the seals against detonation.
These seals were when they were using the single-srping design, for anyone who knows how long ago that was...

Only one of the seals let go, and all of the other faces must have experienced detonation, and this was on their "crappy" seals.

As a sidenote, not having read what was posted by the Atkins business members:

My own personal testing of Atkins apex seals did not give as pleasing results as the RA apex seals.

I would really like to hear your findings

I didn't mean they were bad or that any users of Atkins seals should be worried.

What I said, that in MY PERSONAL TESTING (stressing this point), is that of the two seal brands, the results of the RA seals were more pleasing.

well i wanna hear the results of the atkins seals

You and me both. You know, it might be better if this topic is moved over to the Rotary Performance section instead in my opinion.

I didn't get a chance to read the posts by Mike (posing as Dan Atkins), but I can tell you that I've never had a more pleasurable "rotary experience" than the first trip I made to the Atkins production facility a couple months ago.

Since I was buying my first 'rebuild kit' and had little experience purchasing rebuild parts, I expected to get ripped off, to be manipulated and to have my inexperience taken advantage of by some scandalous mechanics, lol. This was NOT the case. As soon as I got there, I was invited into there wherehouse/engine building facility where I was introduced to several of the employees. ALL of them were very cordial and accommodating and went out of their way to make sure I was well informed about what to purchase and what NOT to purchase. They helped me custom tailor a rebuild kit to my specific needs, and offered a plethora of 'rebuild information' to go along with it... But it gets even better. After purchasing the necessary parts and getting ready to say my goodbye's; I was asked if I would like to stick around for a few minutes and watch the disassembly of an FD motor. I was VERY suprised and immediately said yes. Now you've got to understand that to someone who had never even SEEN the internals of a rotary motor in person and was planning to rebuild it themselves later that week, this was QUITE an invitation. Even better; during the entire teardown process, I was allowed to stop progress and ask any question that I wanted. All of my questions were answered by an employee that had taken it upon himself to be my personal guide. I learned SO much from this. Ok, even better; after this I was given a COMPLETE tour of their facility, got to inspect a rotary powered airplane, got to sit in their 8 second 1st gen. racecar, saw the Camden supercharger production facility--EVERYTHING. Even better; after this, the same guy who posted on this board, Mike, took my car out for a drive with me as a passenger, came back and fixed my idle issue!

Maybe the internet isn't the best conduit for getting to know someone, but the Atkins guys are much better people than I expected. Don't allow some silly internet posts to denigrate the legacy of some of the greatest rotary mechanics in the world.

I believe it was Wankel7 that had that weird Atkin apex seal failure where it looked like the center area was "eaten by a rat"?

I have a pic up on my Hall of Failures...
http://fc3spro.com/TECH/HOF/hof.html

I think we're still looking for the absolute culprit for this kinda failure, but I have never seen a Mazda OEM apex seal do this...


-Ted

LMFAO! OOOoookkkaaayy buddy. So the guys over at Atkins are so pathetic that they had you come on here and give this totally lame excuse? If it was you, then why did the posts by Dan say "MY apex seals"? And its pretty obvious that your style of "writing" (if thats what you call your incoherent BS) is far different from thiers. So now the guys over at Atkins delete all thier posts and try to make up a lame excuse like a bunch of 10 year olds. I can't see people with this intelligence level keeping a business open for long.

-Joe

Where's Landers when you need him hehe ;)

I've done much of my own independant testing on these motors: the RA test was my first, and I have done 1 more on RA seals since then. I have done testing on 2 motors using Atkins seals since I began testing. My first RA testing was done in car... for testing purposes, it was too much of a hassle.

Instead of installing the engines into a car as before, I built a jig to mount the engines to and then rigged up a spare stock ECU to run the engines. Emissions equipment was removed from the engines in testing, all of the rest was stock, save an adjustable FPR and a massively ported wastegate. Fuel pressure was set to a base of 40 psi.
To the flywheel of the engine, I bolted a large brake rotor using some steel 3/8" brackets to attach it and centered it with a dial indicator, and to the bottom of the jig, I welded on a bracket to attach a brake caliper. I ran some custom steel hard line from the caliper to a 3000 psi electric hydraulic pump, and filled the system with brake fluid. I tee'd into the hydraulic line and attached a 3000 psi gauge... Basically, I creating an engine brake to produce load on the engine so that I could produce boost.

For exhaust, I mounted a 3" downpipe, with a FJO wideband into it, datalogging to a cheap laptop. I used a lawn mower choke cable to control the throttle. I used a stock radiator to cool the engine, with a 16,000 CFM 48" shop fan blowing through it. (yes, 16,000 CFM) I used some PVC piping and relocated a stock intercooler to in front of the shop fan to keep intake temps down.

I would run the engines for a break in of two hours at a 3000 rpm under 100 psi of brake pressure. Exhaust was collected into a piece of rubber pipe, which led to outside my shop door. After the break-in, I would do some mild testing to determine how much brake pressure was required to hold the engine steady at WOT at 6000 rpm.... this was tricky, as I did it all ducking behind a stack of 6 sheets of 3/4 plywood behind the flywheel (which I am thankful for... explain later), with my pump, laptop (for rpm) and throttle cable in-hand.

Once I was able to stabilize the engine at ~ 6000 rpm WOT, I would cut the rear secondary injector... and the engine would audibly ping, drop in rpms, and then stall from the excessive load on an engine now running on one rotor. At this point, I would let the engine cool down, and dissassemble. For anyone wondering, AFR's were at ~10.5:1-10.8:1 at WOT at 6000 rpm at 6.5 psi, and spiked to 19:1 or higher when I cut fuel.

My first test using this particular set-up was a set of atkins seals. At 6.5 psi and my induced detonation, 2 of the atkins seals let go. No other seals were damaged, and the endplate was fine. Both apex seals broke where they meet the corner piece, and the seals stayed in their grooves.

I rebuilt the engine again, reusing the coolant seals, and installed a new set of RA apex seals in the rear rotor. Under the same conditions, at 6.5 psi, the rear corner seals all broke, one side seal broke, and the rear iron cracked. ALL of the RA apex seals remained intact. This engine did not stall nearly as fast as the others.

The next day, I replaced the rear apex seals and the rear iron (again with atkins seals) reassembled, and tested again, at 12 psi, via a cheap ball-and-spring manual boost controller. Same break-in, same induced detonation, and all of the atkins apex seals broke.... I assume they broke in the middle, as the housings were extremely scarred directly above the exhaust port. From this, I deduct that they broke in the middle, and then flexed out from centrifugal force over the exhaust port but remained in position due to cocking against the rotor apex seal groove and the edge of the exhaust port, and then crushed themselves against the top of the exhaust port, and crushed. The rear rotor was also ruined.
On this test, one corner seal broke, and the rear iron remained intact.

I took the engine apart again... reused the coolant seals, replaced the rotor with a spare S4 N/A rotor I had laying around, and filed down the grooves in the rotor housing with some sandpaper (this didn't need to be a high-quality engine, and grooves above the exhaust port are not crucial to engine compression).
For kicks, I slid in stock apex seals, turned up the fuel pressure to 44 psi, and set the boost controller to 15 psi.

This testing... was not pleasing... from what I can tell from the datalog, when shit went wrong, I was at 5500 easing off the brake pressure slightly to bring the rpms up. From what I can tell from looking at the mangled mess of iron, one of the welds (AC stick welds) on the jig on the exhaust-side engine mount let go... and the jig was bolted to the floor. The entire engine set-up went catapulting over to the side of the shop, and took out the shop wall (This is why I was glad I was behind the plywood barrier).

The radiator, oil cooler, and intercooler had also been bolted to the floor... the radiator was sheared in half, as was an oil cooler line, which made a HUGE mess of everything. The wideband went for a bit of a ride (killed the sensor, but the controller was fine), the throttle cable was ripped out of my hand, and the hydraulic line sheared off. The UIM physically cracked off of the UIM, and fuel lines were ripped off, spouting gasoline out all over the floor (as I had stupidly wired the fuel pump to 12V constant).

After about 30 seconds, I figured out fuel was dumping, and ran over and kicked the battery cables off the battery. I grabbed the fire extinguisher and held it in hand, while I dumped a garbage can of kitty litter onto the engine-mangled mess.

Figuring I had staved off death enough and with my jig destroyed, I concluded my testing. If I ever choose to do this again, it will be safely on a water brake dyno.

The only real loss from the engine fiasco was I had to replace a wall stud and a piece of plywood in my shop, a wide band sensor, and all of the crappy parts from my test engine. The test engine was built using parts that I found too risky too use on any customers car, so it was no big loss.





To sum it all up: atkins seals broke and tore up housings where RA seals did not. Its FAR from perfect testing conditions, but its all I've got to compare by, and likely the same for others.

HOLY CRAP!
You got a deathwish or something??? :D
Glad you're safe!

Basically, what your experiement concluded is the Atkins apex seals are softer than the RA apex seals. :)
Which most people have already concluded.

BTW, did you know how the Atkins apex seals broke in the center?
Was it all chewed up or did it have a fairly straight crack down the center?


-Ted

Jesus christ Scath, are you insane? LoL.
Man, too bad you didn't tape that, i would actually PAY to see that video! :D

I put more trust in my welds then I should? I was excited and in a bit of a rush when I did it... doing it again, I would have TIG'd it and taken my time.

When the atkins seals broke on the second test, they bridg3ed out the exhaust port and caught on the closing edge of the exhaust port. I had placed a "apex seal collection screen" in between the exhaust manifold and the turbo... basically just a very loose-screen mesh that was ceramic coated. Unfortunately, the pieces contacting the rotor housing were too chewed up on the rotor housing to analyze.

When the atkins seals cracked near the corner-piece, they had a odd chewed texture, not like a crack that you would expect from stock apex seals, or the RA seals. It almost looked like metal does when you bend it back and forth until it breaks.

Less carbon in the atkins seals and lack of hardening is likely the cause of this.


From all of my testing, I have found that: RA seals are the best for standing through detonation.
Stock, 3-piece apex seals are best for sealing and power (outside of ceramic apex seals).

In a recent weekend, I got bored, and I brazed horseshoe nails together (they are flat nails) to form throwing stars, which would stick into the shop wall. I put a rag on one of them, soaked it in carb cleaner, and then threw that at the wall... which, of course, caught on fire.

I always keep three fire extinguishers in the shop at all times, lol. I use them a lot.

Wow, I was looking at prices for rebuilding my T-II when I get it out of the car, and the RA option just keeps looking better and better. Now, the main difference I saw between RA's basic set and Atkins type B was that the RA kit didnt come with corner seals, side seals, rotor oil seal sets and an oil pump chain. What is the likelyhood of these parts going out? (my engine has 187k, I believe, it could have been rebuilt before, but I doubt it.) And do they justify Atkins roughly $500 premium over the RA kit? Thanks
-Rob

Many people don't replace the corner seals or side seals, but I always fit new ones.
Oil chain and the hard oil control rings are usually fine to reuse.

How would I go about checking to see if I needed new side and corner seals or a new oil pump chain and such? I really want a bulletproof motor before I even think about upgrading it. Thanks
-Rob

The metal corner seal part does not usually wear significantly.
I highly recommend to change the rubber center section, which can be purchased separately from any Mazda dealer.
RA also sells this (dunno separately), but it's a piece of "cord" that you cut to length to replace the old pieces - it's a bit hard to explain in text, but once you get it it's self-explanatory.

Oil chain slack specs are in the Mazda FSM.
I don't usually replace it in most cases unless customers insist on it.

Side seals very rarely wear significantly.
Grinding down new side seals from Mazda is a royal pain in the ass.
It's best to reuse the original ones (keep the positions marked!) for newbies, as this keeps the factory clearances.


-Ted

Speaking of Atkins softer seals, I contacted them in mid '04 for apex seals on a rebuild I did and they told me they had new "harder" apex seals they were just starting to get in. Anyone else heard of that? I havn't noticed anyone talking about this, but that's what they said.