Yes, again I say I mainly mentioned the DLC to help identify the coating on the RA seals since at the time nobody knew for sure what it was and somebody asked what it was so I gave them a quick low down. As for DLC lasting shortly it has been long proven to be an extremly long lasting coating. If it wasn't something that was extremely durable and long lasting I'm sure they wouldn't be using it on hip replacements and jet turbines running at supersonic speeds don't you think?

The engines (piston engines) we use DLC coatings in at work put more stress and wear on the parts then a high performance street engine would after atleast 200k miles. We test the same parts without DLC and they are toast after 30-40 miles worth of racing, with the DLC coatings they handle well over 600 miles in a single race and look like new when they come out and we still use them for a second race most of the time. If you could use it in conjuction with the apex seals I'm sure it would dramatically reduce the possability of them sticking or microwelding for the life of the rebuild if not more.

 

oh, of course they were worn. my point was i'm more worried about them breaking than wearing out. if my 500hp fd engine makes it to 200k miles nad loses compression from the seals going away, i'll have absolutely zero regrets.

 

Thanks to all for the informative replies. I was not trying to be confrontational. Just looking for info. I now understand that the primary use of the coating is for the life of the sides of the seal and groove. I apologize for being thick-headed.

Kyrasis6, is DLC simalar to the PCD (poly-crystaline diamond) we use on carbide cutting tools?

 

Sort of... I know there are coatings that repel heat (ceramic). I was also going on what Kyrasis6 and Guitarjunkie said. I've read alot of stuff on this forum about the benifit of the RA seal. That it will warp instead of breaking. Trust me, I don't need to be buying new housings, rotors, and turbine exaust wheels on a regular basis. I know it's part of the game but I would like to keep it to a minimum. That is why I'm so interested in these seals.

My experience in coatings is primarily industrial with a little in piston engines. I didn't think that nitriding would offer up that much heat resistance. But I don't know.

I thought I saw the light with the other two posters. That reducing the friction of the seal in the groove would be benifitial and that the coating was not to prevent wear at the housing contact surface. I did not think it was to resist heat.

Once again thanks for the info. Don't know if I buy the heat resisting thing but i'm sure other posters who are using them will keep us all updated. Hope I'm not hijacking!

 

^ you know what's really funny is i've seen 2 n/a motors break RA seals, but i haven't seen one turbo motor break them. i know it's just coincidence, but i still gotta laugh every time i think about it.

 

naaaaa,
it was probably just uber-poor tuning on the n/a motors, but possibly a bad batch of seals?

 

I know they can be applied the same, and I think we used what your talking about occationally at the CNC shop I worked at. I think the biggest difference is that the PCD is designed to be a hard cutting surface and the DLC is designed to be a hard low friction surface.

 

Yeah, I think that's the only reasonable explanation. Besides, I haven't really seen any negatives to the Mazda seals besides price.

 

I have been abusing the super seals on my daily driver turbo/carb TII and so far so good...

 

i'm running my super seals on 87 octane with a t66

of course it's only 8psi right now. but still, 87 roxors

 

I just ordered a set of the RA super seals when they started reselling them again....after the first batch sold out.

 

with the RA seals being harder than stock, and these being coated, i upped my premix levels to give it a bit more lube and hopefully be a little easier on the rotor housings. of course i won't know if it worked unless i pull it apart after 50k or so miles.

 

Break? As in how? You mean chipped or warped from the first batch?

 

What's your new premix ratio? I'm going to pull apart my NA Fc engine at 10k to check for housing wear with my older RA seals. I premix at 1oz per gallon.

 

I am just running 3mm "normal" RA seals and premix 1 qt per tank of gas along with using stock mech OMP set for max flow.

Took a while to break in, but it has been running great since (on junk housings no less).

Be aware that 50:1 premix ratio will reduce your fuels octane rating by ~ 2 points I believe.

If you use Mercury Quicksilver smokeless premix it won't smoke at idle, but when you forget to bring a quart of that and have to buy the gas station crud it will smoke a bit...

EGTS measured ~2" from the port peak 800C. It is important to keep EGTs down as well since it will burn off lubrication and can cause the seals to warp. 11.5:1 AF in lower boost to 11:1 at full boost richening to 10.8:1 above 6,000rpm.

 

100% capacity of the stock omp, AND a quart per tank (~12-14 gallons)? am i reading that right?

t-von, i was doing 2 oz/3gallon before, but now it's up to an oz/gallon.

 

I am SO tired of this retarded myth being repeated over and over. RA claims their seals are 85% harder then other aftermarket seals (Hurley/Atkins IE playdough). They are no where near as hard as stock. You, yourself can EASILY test this as i just did. I just toke the lower, unharded portion of a stock seal and it EASILY scratched an RA seal. The RA seal could not scratch the stock seal at all. Remember this is the lower portion of the stock seal, NOT the electron beam chill hardened tip with is many many times harder then the lower portion. GO TRY IT. If they were harder then stock they would be more brittle then stock, they are not. Will this freaking die allready???

 

i can scratch a piece of carbide with a sharp piece of aluminum.

but what does that tell you? did you get out the c-scale or are you just soooo ******* good you can look at it and tell? use real instrumentation to get your answer on how hard they are.

 

I Rockwell tested the triangular piece of my original three piece seal today.

It checked between 40 and 43 Rc in a test of three places and with out breaking under the force of the diamond.

I believe it is a 1mm (.040) dia. diamond under 50kg. pressure. Or is it pounds? I can't remember. The tester is set up for C scale.

CRS doesn't even read. Diamond is a 100. Drill bit ~60. Cast iron ~28.

 

Lies.


The scratch test IS the basis for the Mohs hardness scale and is used to determine the relative hardness of two unknown samples.

http://72.14.203.104/search?q=cache:...s&ct=clnk&cd=2

 

If you test the very tip of the seal, where it rubs on the housing i believe you will find 60 rc +