Just curious. These were all the rage back when I was putting my motor together in 2004, but I opted to stick with all OEM internals. My engine is still running strong, has over 10,000 miles of 400+ rwhp abuse and has seen as high as 24 psi. How are the engine with RA seals holding up?

 

+1, did Mahjik use these in his rebuild?

 

i got the first batch from bruce about 2 years ago and they were shitty...i think they fixed the issues. the springs were getting stuck.

 

2years and 13K miles...single turbo abuse up to 19psi

pulls as much vacuum as it did after break in and tuning.

 

Yep, I have them in my rebuild but the car is still on jackstands. I believe Kevin posted some information about his use of them a while back in a thread. I saw one where he was talking about the 3mm RA seals, but I'll see if I can find his feedback on the 2mm ones.

 

I have the RA 2mm seals on a large port about 25k miles no problem. But I am on stock twins..

 

RA Super Seals - 6k km no problem thus far (touch wood) GT3540 boosting @ 1.2bar.

 

I built a few engines with them, only when asked. Most of the time the engines disappear and you don't know their current status. I built one engine for my own car and only ran it a short time before I traded it to someone else. IT changed hands a couple times and saw boost as high as 22psi (on a 9.7:1 HC setup) from what I was told. Eventually it got to have low compression and had trouble starting and idling, though it did not blow up. It was finally removed and swapped for another rebuilt core at about 15k miles from what I was told. The core is still floating around here locally somewhere, and one day I hope to get ahold of it and tear it down to see what it looks like inside. I expect to find worn housings similar to those pictured in the other threads about the seals.

 

i say go with Atkins 2mm and get it cryoed

 

Based on what exactly?

 

ErnieT is using the Atkins 2mm cryogenic treated apex seals running a GT42R pushing 640RWHP @ 31 psi........ if your boosting less then 17-18psi OEM 2mm should be fine (street use)... above that, it all adds up... gettin cryoed atkins 2mm would be perfect

i highly suggest getting your apex seals cryogenic treated, even if it OEM ones... its a little more expensive though...... it makes perfect sence and very pratically and gives you piece of mind getting then cryoed..... and if you have the extra money go ahead and get the rotor housing inner surfaces cryoed.

just my suggestion.

 

There is no bettor then OEM good choice on staying tried and true. I have seen nothing but bad results from all batches of RA.

 

Just try this , there R the best

http://www.hurleyrotary.com/

I have 3mm ones , and the car runs perfect
I know that the best rotary engine builders use these seals

 

3mm OEM FTW

although there may be something to the cryo thing...ErnieT is a god here afterall

still kicking myself for not buying his previous red car

 

Hurley apex seals are utter, absolute garbage.

The best rotary engine builders in the U.S. sure as **** do NOT use those seals.

I've broken more of the hurley 2mm seals than I care to count--20 or 30. The hurley's are very soft and break at the slightest hint of detonation. They don't tear up the motor because they're soft, but you're still left with a blown motor.

They are the *only* seal that I refuse to install in an engine I'm building for a customer. Based on my real world firsthand experience they do not belong in a boosted rotary engine.

 

Hurleys blow! 2mm OEM always!

I cryo treat every motor.

 

Yes they most certainly do.

What specific internal parts do you cryo?

 

the things that you would want to cryo are..... Apex seals, rotors, rotor housing internal surface (wear the apex seals scrape), iron housing, and exhaust manifold.

and you should have a BULLET PROOF motor.

 

I cryo everything in the entire short block when the customer permits the financial aspect. All motors at minimal get the apex seals and springs done. But I have found no benefit to cryo treating the rotors or bearings or exhaust manifold.

This is something that’s gotten big recently, probably because I’ve been pushing it so hard lol!

There are many misconceptions about cryo as there are many processes available. The wrong choice could make or break a motor.

 

so then which process to do recomend?

 

What about e-shafts? And just curious, how would one cryo just the steel 'sleeve' of the housing as turBRO240 suggested?

 

I don't have an engine internals cryoed, but here is what I do have cryoed on my FD:

Clutch disc
flywheel
PPF
S4 TII diff
brake rotors and pads

Check this link for a reputable shop that I've had good results using:

http://www.cryoscience.com/auto/rotary.htm

 

lol how you hear of cryoscience?
There good thats who dave uses.

You can't cryo just the sleve you do the entire housing.

I suggest the method found from cryoscience and another one called Advanced cryogenic processing. It increases the cryogenic results found from cryoscience by 250%.

 

Can someone explain to me the cryo process?

 

In a nutshell, the parts are cooled down below -180 C. This slows down the molecules and makes them basically get closer together (thus making the material stronger).