I'm having a local (but well trained) rotary mechanic rebuild my 2004 rx8 6 port. He says he is going to use a few aftermarket parts. One that has me worried are the Goopy brand apex seals. I'm not looking for power, just looking for a daily driver car, valuing reliability. How long would these last me not hot rodding the car too much and should i steer away from this brand?

 

"well trained" = run. OEM seals always, nothing else.

 

What is the concequence for not using OEM? Are aftermarket really that bad?

 

Worse case scenario the engine won't start and it will have to be pulled and rebuilt again. Could it work out fine? Yes, it could. It all depends on how skilled your rebuilder is with rebuilding Renesis engines (doesn't matter how many older rotaries he has rebuilt). Most reputable builders recommend the use of OEM seals. But you should post his name here, if there is nothing know about him in the RX-8 world then you should probably find a reputable builder that is experienced in rebuilding the Renesis.

My buddy got brand new seals from Atkins that were warped due to a manufacturing defect, it wasn't caught until the engine didn't start and then was pulled apart again. He never thought to spec a brand new seal, hard lesson learned when buying seals from mom and pop shops with very little QC.

Also read this guys story, he was in denial. But in the end it was bad decisions made during the rebuild process.

https://www.rx8club.com/new-member-f...ebuild-265092/

and then:

https://www.rx8club.com/new-member-f...groove-265532/

 

Ok thanks, I really value your opinion. So as long as it starts and he hasn't done anything crazy wrong with the rebuild, I should see a bit less than OEM lifetime correct?

 

Well, it can still start and have poor compression. And less than stellar compression will have an effect on longevity, but most importantly performance.

 

Ok I got it now. Thanks alot man really appreciate your advice. I'll ask tomorrow if he can put OEM seals in it for me.

 

There are no aftermarket seals that will last longer ( and not screw up the housings anyway) than OEM Mazda ones. Mazda has spent Toms of money and has a lot of engineering into there seals

For an NA engine there isn't anything better except Ianetti ceramic seals....and you don't want to ask how much they cost 😎

For a FI engine build you have to look at other things that could kill the engine and make decisions on seals. Sometimes the aftermarket ones work well for that application where detonation strength is worth the risk of the downsides

 

Iannetti last longer than OE and are much gentler on the rotor and housing wear surfaces, Mazda doesn't use them due to the cost difference. Makes no difference for this thread though for the same reason.

 

That was exactly my point......

 

Except you said that 'there are no aftermarket seals', just making a factual clarification

 

True...although Ianetti is barely aftermarket....they have been involved with Mazda for so long it is a very thin line

 

So your saying that Atkins is a mom and pop store that doesn't know Mazda rotary engines?

 

LOL. ...they sure don't have anywhere near the engineering or finances that Mazda has invested in the OEM seals

Other than that don't get me started

 

What about Ianetti ceramics?

 

For an NA build ...they are awesome. They hardly wear...and are gentle on the housings

For FI ...as long as you don't detonate they are great...but if they crack you loose everything

 

Like everyone said, they are supposedly very good but will cost you an arm and a leg.

Also, not sure how true this is, but I read that ceramic seals are superior in a lot of ways than the OEM steel ones(they will work well even when there is little lubrication). The only downside is that they are more prone to detonations(a bigger issue for the FI crowd), as they can shatter.

 

Yes, yes I am. It is literally run by a mom and pop. As for them knowing rotaries, I would say they do, but I would never let them rebuild any of my engines. My buddy was told that Mr. Atkins himself checked every seal himself and so there was no way it left the way it did. The engine was pulled, the faulty (scalloped) apex seals were identified, and they were replaced with OEM seals and the engine has been running for several years now.

 

i dont see the big deal here, just replace the apex seals through the spark plugs holes when you change your oil like most people here do