Just wondering but has anyone herd anything good or bad about avation seals. The RX7 store seams to use them and said they haven't broke one yet. If anyone has any info on them That would be great.

Sorry if this is a repost

 

https://www.rx7club.com/rotary-car-performance-77/rotary-aviation-apex-seal-report-397712/

 

Not a good idea, IMO. They prematurely wear out rotor housings by a large factor. They scored my housings and I barely used the seals for 10kmi.,

B

 

After reading that thread, the motors don't last too long using these aviation seals.

Just out of curiosity, why would a reputable shop use seals that seem to be under par?

 

whats wrong with Mazda seals....they seem to be the best bet as far as reliability.

 

You need to look deeper than that thread. The advantage of these seals is they don't break under detonation like stock seals do. They warp. This saves you a ton of money when rebuilding since now your not having to replace damage rotors or housings or turbos ( from having a seal take out the turbine). So far I have 14k on my 91 NA engine with RA seals and the engine seems to be still getting even stronger. My OMP doesn't even work that well so I've been premixing that whole time. Hell I've actually gone several full tanks of gas without premixing. I have zero flooding or start-up issues.

So far it has been shown that most of the lost compression threads dealing with these seals have been due to the early batch seals and their cutting process. That has since been changed. Also the other cause was the use of their springs (which were not heat treated). This caused extra chattering of the housings cause of insufficient pressure and even lost compression. Knowing this, I built my engine with stock apex seal springs. One last thing, during assembly I noticed that the land that the small apex seal spring rides on was rounded off. During my assembly, the small spring would slide past it and end up at the bottom near the corner seal. This small machining error could also be the reason most lost compression due to the small spring sliding out of it's location during assembly and not providing even pressure thoughout the apex seal. I corrected that small problem by using my dremel to square that section so the spring couldn't slide up and over it.


As soon as I get my 20b up and running, I'm going to pull my engine apart to give you guys an update as I promised a while ago.

 

See my above post. They have their advantages. Personally I feel the RA seals really have their place. It all depends what you want out of them. Since they do (supposedly) wear the housing faster I wouldn't recommend them for rebuilds if your trying to get thousands and thousands of miles out of them. When I say thousands, I mean 40k+ territory. Stock seals have already been proven for that. Now if you want to build a over stressed...highly boosted engine that can handle some knock, I would seriously recommend these. They can take a beating. I mean lets be real! When was the last time you heard of someone building a high hp 13b beast and putting more than 10k on it? Not very likely. I feel if you can get 30k out of these seals under high boost, then they are well worth it for what they cost.

 

I'm going to give the RA Superseals a shot in my next rebuild. I've heard a lot of complaints about premature housing wear, but I think I may have the solution. JHB's Performance Cermet A housings have higher wear resistance than stock. I'll let you know how it works out.

 

They couldn't hold up to a T04Z that I just put on the car. I guess mazda didn't anticipate a large single turbo on the rotary.


But in the that thread, they mention that N/A's motor's worked fine. It's the turbo'ed cars that had issues.

 

88integraLS had deep scoring on his N/A's housing after just a few thousand miles too...

I will be opening up one of my TII's engine's in about 2 weeks that had about 25k miles on it--using RA seals and springs. Should be interesting, but I'm already planning on not being able to reuse the housings.

 

We give the customer the option of Mazda or RA seals. For a single turbo car that is going to take some abuse then we go with RA. They will hold up to some detonation which Mazda seals will not. Most of our customers dont drive their RX-7's daily so premature wear on the housings could take 5-10 years to show itself.

 

Thx! Perfect post which just proves my point about these RA seals having their place.

 

That thread is also a couple years old and around the time when these seals had those cutting flaws (early batch) I mentioned earlier. The cutting flaw over heated the seals from the start so they warped faster in turbo charged engines (cause turbo engines create more internal heat). That problem has been corrected.

 

Just a data point, I rebuilt the engine in my (former) 88SE a few summers ago with RA seals and used-but-decent housings. I tested the compression a few weeks ago before I traded it for a 1st gen. Over 25k miles on the engine, 100% run on premix, and I was making around 100psi on both rotors. And the engine wasn't the tightest build ever - side seal clearances were probably on the loose side.

Again, NA, no boost.

-=Russ=-

 

BDC where are the compression facts?
the marks have minimal to nill effect of compression
as long as you have the omp or premix

 

I'd have to agree with what someone else that has already stated that these seals have their place. If you want 100k miles then stick with stock seals. But if you want a seal that will hold up to some detonation then these are the ones you want. How many miles are you going to accumulate at 1/4 mile at a time. I'd rather lose compression than spit seals out my turbo. For one if you've ever grenaded a motor with stock seals your replacing or rebuilding a lot of ****. Rotors, rotorhousings and not to mention most likely rebuilding a turbo. Those exhaust turbines sure hate stock seals. RA seals warp and you lose compression big deal open it up change the seals and your good to go back to the track.

 

you and i are of similar minds. whenever i'm able to continue with my 13B build, i plan to have JHB do their thing with my rotor housings. i have RA seals in my streetport 12A, but until i pull that motor apart again, i won't know if they are ******* up the rotor housings - and i don't plan to pull that motor anytime soon. besides, the 12A will probably never see boost, whereas the 13B WILL.

 

If Your Building A Grocery Getter Then Use Mazda Seals. If You Plan On Running Some High Boost To Kick *** Then The Smart Thing Is To Use Ra Seals. I Would Only Use The Ra Seals& The Springs And Everything Else I Would Use From Mazda. My Friend Use Mazda Seals In His Daily Driver And He Is Making 440whp. I Know someone who's boost Spiked To 55psi& He Broke The Backplate In Half, But The Ra Seals Didnt Bake. I Hope Anything I Told You Could Help.

 

Thanks guys i just hope they can hold between 8 and 15 puonds of boost on a half bridged motor. Think NRS seals would be the better choice.If so let me know iam a noob at the rotary and any thing would help. I would just like to get at least 2 years out of the motor on weekend driving only, and maby once through the week.

 

Stick with stock seals for what you want to do. Save the money spent on ceramic seals and put that into your motor/turbo setup.

 

i blew my motor once with this seals but ive been running with the same seals and they are pretty good and they hold a lot too just be carefull don't run lean

 

Agreed. The NRS are really the best choice but are really expensive for your goals.

 

Iam already running a garret To4r with a front mount and the power fc. Also 550 primaries and 1660 secondarys on the fuel with 2 255 pumps. Dont think running lean would be a prob. I would just like to make as much power that is safe to take out and race at the drag strip and some road coarse racing from time to time. I just dont want to put this motor to gether and have it go out again in 8000 miles, but that was an over heating problem. Stupid Mustang.