scathcart

I've recently taken 3 engines apart using these seals. One mostly stock N/A which was kept under 7500, one street ported N/A with exhaust, intake, and an S-AFC, and one N/A BP with a 150 hp shot of Nitrous.
These engines all had low compression, and all had less than 15,000 miles on them.

All of the the springs were completely flat. All of the rotor housings are now complete garbage, including the Bridge engine, which only saw ~4000 miles and used brand new rotor housings. The housing damage is to the point of which 100% of the chrome around the exhaust ports is missing; I have never seen that before.

All of the rotor apex seals grooves are now without of spec. So far I am out 6 rotor housings, six rotors, and all the internal seals.

I Haven't bothered contacting RA... if it were one engine, I might have, but this was three in a row all with the same issue.

All engines were premixed, between 80:1 and 120:1 depending on the engine.

I have one engine left currently running these seals, from an early batch, using stock FC springs. It currently has well over 40,000 miles on it... I wonder if it has any chrome left on it. It surprisingly runs very strong.

I'm not using these seals anymore... they take a ton of abuse, but they destroy rotor housings. Stick to Mazda or ceramics.

t-von

iTrader: (8)

Don't you think it's a little premature to assume that the seals themselves destroyed the housings? In the three engines, you claimed that all the springs were flattened. That means that the apex seals didn't have the proper forces on them to properly seal for compression. The now "FLOATING" apex seal is going to cause more damage to the housing because of the seal bouncing of the rotor face due to low spring tension. I'm only bringing up this point because I have yet to see someone pull their engine apart with Mazda oem springs and the RA seals. I haven't heard of any complaints from anyone running that combination.

dubulup

I've got RA seals and springs in my motor 8900 miles...no issues, I must have missed the warning about high boost with these springs, or the warning wasn't on the package when I built my engine.

GUITARJUNKIE28

i've used these seals in like 10-15 engines i did last year. i don't think any of them have more than 15k miles so far, but i'll be watching them closely...

Mahjik

iTrader: (1)

I got the RA kit as well. I didn't notice the warning, but I was missing the springs anyway so I ordered OEM. I only knew the warning about the side seals. Do they have the spring warning on their site (as I didn't see it)?

dubulup

^ I think after the first couple of batches they put a sticker on the package (also changed how the packaged them) that said don't use with high boost. I didn't know about the warning until someone brought it to my attention.

didn't mention what high boost was either...I'm running 17psi. High for a stock twin turbo rotary, but...

Mahjik

iTrader: (1)

I guess that would be the reason I never saw the warning as I never saw the spring package.

GUITARJUNKIE28

so assuming you did use the RA springs (to save the $70 on oe), how would you go about heat treating them?

peejay

He's not describing chatter, he's describing scoring, which has nothing to do with apex seal bounce.

Besides, the springs have ****-all to do with anything when the engine is running. It's all gas pressure underneath the seal and centrifugal force, which are both far stronger than the springs are, even separately. Flattened springs stem from overheated seals, which might happen if you're using the seals to machine out the housings.

88IntegraLS

You are the man. My engine has about 10k on it now and I've had the housings out about 8 times (my journey in the land of getting side seals to make it over my ports, heh) and the housings are scored uniformly. It hasn't seemed to be getting worse and all the chrome is still there and it does run strong, but I'll stick with Mazda from now on too.

Good to know they take abuse. I'm about to experiment with boost and street tuning.

88IntegraLS

Springs only add necessary force under the seals for startup. When the engine is running, the combustion and compression pressure leaks under the inner seal gap to force the seal up, then there's centrepetal acceleration when they trace the top and bottom of the trochoid........

By the way the damage RA seals do is many score marks parallel to their travel; chatter and seal bounce causes linear marks perpendicular to the seal travel and parallel to their axis.......

scathcart

Chatter runs perpendicular to the trochoid surface.
These housings were scored following the path of rotation.
There is no question that the seals are to blame.

Chatter also won't completely strip the chrome from the areas adjacent to the exhaust ports. Galling will.

scathcart

If you do a search under my name with these seals, you'll find posts describing where I tested these seals myself against detonation, and made comparisons to atkins and stock seals. I did my testing while building my own engine brake, and I was, up until recently, a huge advocant of these seals, so I don't think I am giving up too early.

I built a lot of engines with these seals... the three that died most recently were from low compression caused by scoring of the rotor housings. The ones prior were pulled apart for various reasons, such as coolant seals failed from overheating, porting requests, spun bearings, or cracked endplates (RA seals would endure detonation, but the endplates would not). Most of these engines were low milage, and even those taken apart just shortly after breakin were showing light scoring marks. It was at that point that I went back to using OEM seals, as I did before, and many of my problems disappeared.

I should make a disclaimer that I very rarely build engines for street use anymore. Nearly all of these engines were running very high AFR's (and thusly, VERY high EGT's), running on full premix, and spending nearly all of their running time above 5000 rpm.

scathcart

One of the few street cars that I built with these seals has over 40,000 miles on it, and is still running very strongly... but overall, I just don;t think these seals are safe for rotor housings.

GUITARJUNKIE28

i guess i'll find out...hopefully not the hard way :/

t-von

iTrader: (8)

Ok I can understand that however, think about this. Most of the people who highly modify the 13b do so with the engine not lasting 40,000 miles of hard driving(lets say 400+rwhp). A couple hard pings and the seals let go. I really don't see the oem seals lasting that long in a highly modified rotary unless the car is occasionally granny driven. I think the RA seals are better suited for this. They've have been proven to take the abuse the oem seals can't. So I guess my point is, I feel the RA seals and the engine to which they are in will last longer in a highly modified situation as compared to the oem seals which can easily let go due to knock. The RA seals have their place..the engine may not last forever but they have their place.

peejay

40,000 miles is about 1/5th - 1/7th of what one could reasonably expect from a street driven rotary. Will it continue on to 200k and beyond?

Time will tell, of course.

scathcart

But less than 15,000 miles on a stock and street-ported 6 port N/A engine? N/A's don't detonate. That's crap milage. Stock apex seals would have lasted 100K + miles, 7 times as long.

Yes, I do think 40,000 miles is short for a highly modifed engine with stock seals. RA seals can take detonation, but who cares if they toast your rotor housings and rotors in 15K miles? Or, in the case of the bridgeport, after 4000 miles? 4000 miles before COMPLETELY destroying brand new rotor housings and rotors? Even if the stock seals only lasted 20,000 miles, that's still 5 times longer than the RA seals, and at least one rotor housing and rotor would be resuable.

I'll snap some pics this weekend of how bad these rotors are. I'll grab some ultra-high res pics, so you can see the scoring.

Host?

peejay

Hell, makes carbon seals look like a deal, at least for N/A guys.

$30 apiece and you *know* they are housing friendly. They don't last long relative to stock iron seals, but at least the seal is the fuse and not the housing.

t-von

iTrader: (8)

With batch did you use on the rebuilds?

Curtisleeyoung

I'm using the RA seals as well in one of my engines, Running well, sometimes after I shut down I hear a thump like the engine rotated one last time without spark. Is this a sign of low compression?

RX7MONSTER

I have put down a deposit to a car from Japan by Top Secret Japan ( tuning was done there )... I dont know who built it.

The car is using NB Seals.. What are NB Seals? This car is a top speed/quarter mile car. It has done 298Km/H top speed and 10.6Second Run

Are they ceramic aftermarket seals? Has anyone used them? What are they worth?

I just want to know, because when the motor blows ( if it blows ) i will be buying NRS seals....

Thanks

scathcart

They have varied... I was using the seals back when they were single-spring units. The 40,000 mile engine used the stamped numbers w/ stock springs.

GUITARJUNKIE28

anyone notice that some of the recent ones haven't been marked with the corner pieces?

teknics

iTrader: (4)

i just received my RA 3mm seals the other day, ordered them on 7/21, they are stamped, both the little and big pieces.

kevin.