I did a search didn't see any thread posted about this so I thought I would share some links and open some discussions.

first up, some of you may have herd of NRS ceramic apex seals, there about 1500-1000 for the set
here is a link to the testimonials
Testimonials

if you go down there is a part about a cerment coated rotor housing with nrs apex seals that run hard for 80k miles and the inside looks perfect, what I don't know is if they took the motor apart because of some other failure or just to see how it was doing, the housings look perfect and the results are promising

so I found JHB the guys that do the coating
J.H.B. Performance - Cermet-Coated Rotary Engine Components
that is a link to a set of informative information

it also seems both NRS and JHB went to sevenstock 7.

has anyone here used there service or even heard about them?

it seems if mazda took this tech and retooled we could get a 200k motor from the factory

 

NRS has been around forever. I use their seals and it's excellent.

as for JHB, some people said they are ok, some people said they did a horrible job, Im looking for a FD now and when the time comes, I will try their Cermet X with dr I ceramic seals.

Mazda couldn't figure out how to make a longer lasting Apex seal for endurance race, that's why they asked (hired) Dr. Iaantti for help. and the product was Nitrated Ceramic seals. a set of that will cost you about the same as 2-3 good brand new housings. Throw a set of Aluminum side/int housing and your car will last forever I'm not kidding.

Just make sure your tuning is good, cuz when Ceramic seal breaks it does WAY MORE damage than Iron seals. yes! Ceramic does break !

there is no way Mazda can have all these stuff on a street RX car, not for 30~ K at least, 100+K ? sure, but would you buy one ?

 

yes, look at the 787B, they ran Lemans, took it apart and measured the engine, put it back together, and then it did weekends and track days until 2011, when they rebuilt it to go vintage racing. they did a nice job too, exterior is still circa 1991, so its got plenty of rock chips, and touch ups and stuff. the loosing Jaguars are all over restored, they look like they never got raced in the first place


notice the special 4 rotor seal case, and the different color on the rotors

true as well. look how much JHB charges! its as much as a new rotor housing....

 

375 for cerment A coating on one renisis housing doesn't seem bad especially if it fixes them new cost 720

 

The product sounds compelling. They take used housings and turn them into a better product by using a different coating to the chrome.

They must have a good method of applying the new coating to ensure the tolerances are better than a brand new housing.

So why did mazda use chrome instead of cerment? If this product does what it claims then we should all be using it.

 

Read the tech papers it explains it in more detail but basically Mazda had so much money in tooling in the 60s to change the plating so they changed seals to make it work. And at the time cerments coating where under developed

 

That's IF your old housing is reusable. which most of the time ---- it's not. reason is the Apex seal corner piece gonna damage the rotor housing beyond the chrome and hit the Steel part of the housing.

Would you go buy a NEW housing, which you KNOW will work. send it to them, scrap off completely good layer, and do the coating ?

and again, the coating's review is really mixed. some say it works, some say it sucks. Mind you, they didn't do Mazda's 787b coating. if I go try them, I am sure I will go Ceramic x, cuz if I am going this route, there is NO REASON to go cheap anymore.

 

i don't know about the 1960's, Mazda didn't show an engine with ceramic coatings until 1988, which is also the first time they tried aluminum rotors, so while they were invested in the chrome coatings, they also didn't really try the alternates until recently.

NSU had an aluminum rotor in the 60's, although it doesn't retain enough heat.

 

Aluminum rotors ran really well, but it's a bitch to make ($$$$$$) so we're back to Cast Iron Rotors.

they already hint the next RX car will be more expensive, probably just testing waters to see how people react. but honestly I would rather they sell it for higher price, so less IDIOTS will have access to it. Look at FD compare to FC.

 

in what? i've got no records that anyone's actually used any, except that NSU chart from 1969.

Mazda used aluminum rotors in the Rx-03(?) showcar from 1988ish, but they didn't even make it into the 787B engine, so there may be some fundamental flaw.

 

I would look at race teams to see about the aluminum rotors, like purto rico.

on an earlier question if they brought out an high end rotory powered car, like 60-75k. I wouldn't buy it, but I would drool over it. and possibly bring up mazda sales.

and I would try to get a used one.

 

There were papers talking about it, but production cost is too high at the time. I dont have it on my laptop though