timrxmotors

I now have my 12A turbo housings back.The finish is very good.My only concern is I have about 0.2mm more coating thickness than a new rotor housing,that means 0.2mm less rotor clearance,not what I need on a high revving high boost engine!
Have you measured your TII housings?

BLUE TII

iTrader: (9)

Right, CereMet not ceramic

Doesn't CereMet pretty much just refer to any of the proprietary coatings that use carbide particles for wear resistance in a matix of another material?

altf4

on JHB's site they talk about ceramic coating (no mention of Cermet). I was thinking ok yes the ceramic will be a thermal barrier, but eventually wont the rotor heat up enough to expand, and when it does the heat will be traped in the core after shut down since there will be no oil flow to carry the heat off.

So as the housing contracts back down to its cold sized, and then the rotor will still be at its expanded size, and might bind on the contraction rotor housing.

Also if the rotors ceramic coating isnt even it can cause hot spoting and the expansion rates can get messed up.


are these thoughts of mine legit or am i just nuts?

Scalliwag

The hard chrome on the sheet metal insert on the aluminum housing as well as the cast iron rotor all have different expansion rates. It's not an ideal situation but the clearances are factored in to account for it even stock. The problems compound at higher rpm which sucks. Cryo treating the housings and rotors is the only way I know of to fix the expansion/contraction issues.

altf4

what effect will cryo treating a cermet coated rotor and housing have on the cermet or ceramic coating? if you know?

Scalliwag

I am not sure. But that's half the fun of trying something

altf4

very much true. just have to wait till i have the extra funds to take risk such as this. but it isnt my dd so it isnt too bad.


Mayb cryo treat then plasma coat, but then the hot plasma metal coat will aneal the cryo metal. hmmmm!


More School here i come!

Scalliwag

Without a research and development lab sometimes the only alternative is trial and error. Ideally you could make several setups and each have a different variable, no cryo, cryo'ed before spray, and cryo'ed after. Throw in trying different spray methods and types of spray material and a very controlled environment would just cost out the ***.

Hopefully some of the guys start reporting back the results pretty soon.

BLUE TII

iTrader: (9)

From JHB site

We offer ceramic coated rotor housings that are proven to last up to 10 times longer than stock rotor housings. In addition to their outstanding durability, these performance rotor housings also generate less friction and help generate more power from your engine. We offer two different coatings, referred to as Cermet A and Cermet B. Both coatings contain carbide particles for wear resistance. Cermet A coating is the exact coating used by Mazda in the 24 hours of Le Mans winning 787B racecar. Cermet B is used in many Nascar and Formula 1 racecars including the Ferrari F1 team. Our rotor housings are guaranteed to meet or exceed original factory specifications. We can also repair and cermet coat your damaged rotor housings. We can apply one of our performance coatings to either new and used rotor housings. The cermet A and Cermet B coatings are ideal for high performance street or racing applications. These coatings are highly recommended when using aftermarket steel apex seals or when using ceramic apex seals. We higly recommend using JHB Performance apex seals when using ceramic rotor housings as they are designed and tested to be long lasting and durable with this coating.

Though they do mention Ceramic coating twice they use the term Cermet seven times and define it properly as a coating containing Carbide particles for wear resistance in a carrier.

The rotors are coated with a thermal barrier which since it doesn't have to "wear" at all is most likely a totally different coating than the Cermets.

altf4

yeah,

I am going to post a new thread that is related to this, but isnt a re-post.

i will need some guinie pigs!

fastcarfreak

Well i guess i got a couple of questions. I thought the price on these things were going to be like 300 a housing. At 400 dollars a housing, and not much test time on these things, dont you guys think people are going to go with new housings for a bit more? When i first heard about this, with the estimated 300 dollars, i was really excited. But, now after seeing the 400 dollar price tag for the FD housings, im not so excited. I understand that this stuff costs to develope, so i guess i will just sit and wait to get some reviews from people who use them.
Also, how do these new cermet housings react to broken apex seals? Do they have a better scratch deterence then the factory mazda housings? It would be really cool to hear that they do. If these housings can stand up to apex seals breaking and digging into the surface then maybe these will be worth it.
Until we get some testing in order, i will be waiting patiently
Adam

altf4

some ammount of people need to be test subject. I am willing to be one once i have the funds to cover it all.

I will gladly accept donations so that i can be a test for all this

Scalliwag

Have you got your housings back or an update Ian?

SnowmanSteiner

From what I understand the cermit coating has a higher hardness than the stock chrome, so in theory it should be harder to scrape them. Don't expect miracles though, I still believe that a broken seal will scrape the housings up. The benefit of the cermit and ceramic coatings is that if you do scratch the housings, you can get the damaged part resurfaced for cheaper, that way you don't have to buy a new housing. That is the main benefit when it comes to scratching. I plan on getting my housings coated by Scalli over the summer, once he has setteled into his new shop. By the way how is that going Mike?

- Steiner

shotty

IIRC to anneal metal, you bring it to near critical temperature and then slowly back off the heat until you're back to room temp, so I doubt any annealing will take place due to the rapid cooling after the plasma coating. Could it change the heat treat state? sure, but I don't think it'd be annealed.

timrxmotors

My 12A housings have been sent to a grinder to be ground back to original spec. I had 5-6 thou too much coating on the housings. JHB did offer to sort them out,but I don't think they can do it,else the housings would not have left their shop so out of spec.

now

iTrader: (1)

I am looking forward to getting my ones back to see if they are done to spec.
I will be doing some serious measuring this time.
matt

Michael_Rudy

Ya i was going to get my MFR 12a PP housings done by them because one has a little flake of chrome missing, but i think i will wait a while to see how well it will work, because this engine will spend its life above 9000 rpm

doridori-rx7

iTrader: (3)

I understand the advantages of the coating and I expect to get some of my ACRE customers to want this at some point.. but I have to say pricing is out of the park. I can get pair of brand new housings ( S5 TII) for under $800 Canadian, also under high hp apps on the street I usually do rebuilds every 80-100K.. Although thier are some advantages to running the Cermet coatings.. the costs far exceed the advantages to 'most' people.. I hope the costs come down.. for aircraft guys that's a minor cost to them.. but to automotive guys, it's way over top.. at least from what I've seen, in my area.

IAN

iTrader: (3)

Really. $800.

Maybe I should get a set Since I did not manage to steal lawyers spirits housings

doridori-rx7

iTrader: (3)

REW are a bit more. pm me if you want some.

fastrotaries

In the few coming years, this WILL be cheaper due to the availability of housings.

doridori-rx7

iTrader: (3)

damn, I made an error, $800 was for a set I bough that they had in stock froma no show customer.. my pricing is $1200 cad. for a pair of S5 TII and $1300 for REW. sorry.. i may be able to go lower.. in retrospec, the cermet is still high but it's a start at least and that's what's important.. I know my aircraft customers are going to want the 'new A ' option

SnowmanSteiner

Their pricing is very reasonable, considering the research and design time they have into this cermit and it's applications. You're actually saying that the cost exeeds the benefits? So the lowered friction coefficient, harder material, higher resistance to heat, increased engine life isn't worth 800 bucks, but it's okay to spend 1200 for a set of new housings that don't meet the same performance as these? Plus the fact the next time you blow a seal you'll be shelling out another 1200 bucks whereas the person who bought the coated housings will be shelling out maybe 400 bucks to get specific parts coated again. So now one person has spent 1200 dollars and the other has spent 2400 and that's not a ******* bargain?

- Steiner

doridori-rx7

iTrader: (3)

your assuming allot of things that $1200 is Canadian the converted cost of new' B' with approx shipping and ins. is pretty much the same. As for the blowing of the seal, I do beleive both serfaces would be damaged regardless. So I don't see where your trying to go with that point... Not sure about down there, but I don't know too many rotary owners who actually rebuild before they blow an engine.. if they do, they usually get a JDM 13BT that's worth less then 1/2 a rebuild. with an extra tranny and ECu included in that bargin. THe people who buy new housings are the ones who want OEM spec. As I said , my aircraft customers will want the works, becuse $1200 us is nothing for aircraft parts. The auto guys won't want it till it drops below the cost of a new set of housings..

Sorry if you don't like that , but that's the economics of it around here..