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It's an Atkins water seal on the front rotor that has only seen 1200miles, approximately 200 of them on track. The inner seal on the rear rotor just looks fine, not one crack like this:
I haven't built many motors, but OEM seals are preferable for everything but apex seals in my opinion.
I'd shoot Ray Crowe an email or phone call to order some seals, they're OEM and he's the cheapest you're likely to find. International shipping/duties may get pricy, but if you have an APO address (or access to one) it'll ship like it's in the continental US.
I've seen the same thing with aftermarket seals but it was after about 10,000 miles. The particular car was tracked and ran Evan's coolant. It never overheated until it started pushing coolant into the overflow. Upon disassembly the coolant seals looked like yours. I strongly prefer oem parts in most cases but have built with aftermarket when customers requested it.
your malfunction is in the exact area of max compression/heat. after extended normal usage the bottom of the compression seal groove in this area always becomes pitted.
either you had a boatload of detonation or your thru bolts caused the problem.
loose clamp on the plates causes compression and coolant seal degradation.
loose clamp can come from too little or too much torque. factory spec is 28 ft pounds.
too much torque stretches the bolts into yield.
for full coverage of this important subject please visit the "Tension Bolt Technology" section of my website;
i wasn't aware of Atkins offering a non Mazda inner coolant ring. they do offer their own outer ring. i would NEVER use anything but Mazda for the inner ring. lots of tech there...
since you say you have no seal problems on the rear rotor it probably was detonation.
please do what you need to fix the detonation or you will be disassembling another motor. if you are tracking the car you do need AI as well as really good fuel and a conservative ignition tune.
I have torqued the tension bolts to spec, but since I have reused them in my last rebuild I don't know, if the previous owner did so too. Some drag guys here in Germany sell their own stud kits for around 340$ at the moment, maybe I give them a try. He says they are 12.9 Grade. The Chips Motorsports you recommend in your article are 570$ because of customs and shipping. Thats a little bit to steep for me right now.
The rear Rotor was killed presumably by detonation, so it would also be a possible reason.
Today I have further inspected the O-rings, the cracks are very deep, a little bit more and they would have gone through (The back side looks fine). So the 2 inner seals of the front housing are definitely trash. Would you only replace those with OEM, replace all inner seals or replace all water seals? All other seals (Besides the two cracked) look fine.
your link does indicate Atkins offered non OE inner coolant seals. i visited the site and the inner seals currently offered ARE OE Mazda. i would never use any other inner seals than Mazda. also, FYI, i would also never re-use inner seals. i currently only build my CPR spec motors from new blocks. when i disassemble them i discard all the inner and outer coolant/compression seals. i am dubious re re-compressing the inner seals. i am sure many people do it and it works but i am not going to roll the dice on a close to $10,000 engine for a few dollars saved.
Atkins has made there own outer seals for quite some time and they have gone through a number of iterations including square etc... they often are just a tad too long but work O K if one is careful. i have no problem with using the outer seals from Atkins.
i have built around 180 BREWs and have worked with Atkins pretty successfully over the last decade.
like anyone (including me) or any business (in this case Atkins) it has not all been perfect. i haven't used their apex seals for almost 10 years as they were (are?) too brittle. i stopped using Atkins corner seals as the OE seals have a chrome surface and are better on the side irons. i stopped using their normal offered corner seal springs and now always specify the OE FD springs which are inconel. with the better apex seals available today we generally don't break apex seals with detonation. the next weakest link with detonation is the corner seal spring. detonation flattens them as it is around 3500 F (!) in the combustion chamber. the OE FD inconel springs hold up better than the neat looking chromey springs that Atkins generally sells. Atkins, of course, also offers the good ones, you just have to ask.
corner seal spring height (.18) is one of the best detonation indicators. flattened corner seal springs reduce compression as much as 30%.
another Atkins speed bump was the main rear seal. for a period they were using the RX8 seal (i think it was RX8). it has half the sealing height and often leaked on a BREW. i authored a thread on this and they eventually changed back.
i like Atkins and have done lots of biz with them but you just have to make sure you are asking for the correct items.
bottom line is whether you are rebuilding your own engine on a tight budget or a new block you want to always buy the best items or the money saved is followed by a lot more money spent on doing it over again.
another Atkins speed bump was the main rear seal. for a period they were using the RX8 seal (i think it was RX8). it has half the sealing height and often leaked on a BREW. i authored a thread on this and they eventually changed back..
the Rx8 seal is cheaper, and they still throw it in when they can. i used one on my friends lemons car and it spun in the bearing and caught on fire, which was pretty crazy
it is weird though, Mazda used on 266,000 Rx8's without any issues, so something must be different enough
01-18-22, 03:52 PM
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