Hey all, with some of the current interest and cusiosity of wether or not these parts are working, I decided to post some results from the cermet engines. I just did a compression test on a 12a built with cermet b housings and lapped end plates, after 1200kms it has 120 psi compression at cranking on both the front and rear. Motor is needless to say running awesome. Very happy with the cermet housings as is the guy who owns the car.

I have some other motors with Cermet in them as well, and will post results once they are broken in as well. I had no issues with tolerances or anything. Housings looked great and are working great.

 

What apex seals are you using with them?

 

Good news to hear wpgrexx....I've done 2 motors so far using JHB housings. I've used the stock Mazda 2 piece seals to build both motors.

 

stock mazda 2 piece 2mm. I think this is like the 5th or so motor I have built with the cermet. I like the way the cermet breaks in, rather quick compared to new chrome.

 

What is Cermet?

 

See this site: http://www.jhbperformance.com/

 

Do you have any sort of dyno results? Are the motors more potent with the coating? do they run cooler? any other information?

 

Breaks in and wears out way too quick.Has anyone had a cermet engine apart to see the wear? All those little bits of cermet ripping everything apart.

 

OK, what's up with this. I have finally started to get my motor back together and now I see this. All of my housings have been done with cermet b. The motor had 100k on the side plates and so I decided to have them cermet coated instead of buying new ones. I opted for this instead of just lapping the housings and loosing the nitride suface and having them wear out even quicker. This seemed like a good option. It is supposed to last longer, wear less, and reduce friction. Has anybody else had there engine apart to see how this stuff is actually holding up. I am going to hold off putting my motor together now.

My rotor housing were also coated because they were scored from using some RA seals. The seals were in there less than 2000 miles. When the motor went together the housings were fine and had only 35k on them. when we pulled the motor back apart to fix a sticky side seal, the housings had scoring like that in other posts that are starting to come up. Needless to say I won't be putting the new set they sent me for warranty. To many people are having problems with them creating too much friction and pulling tiny bits of metal off the housngs. Now this problem with the cermet housings in the pic.

I found this thread after hearing of problems with this stuff from my builder who is concerned about building my engine with these housings. He called around and asked me to search for info on how this stuff is holding up. Go figure, the first post

Mike

 

I'm so interested on this topic.

So many questions yet no real time data on these

 

If I remember correctly, Tim had his housings reground somewhere else after he got his housings back form JHBperformance. So his coating might have been to thin to last and protect and do all the other stuff they claim.

Details are in this thread: https://www.rx7club.com/showthread.p...hlight=cerment

 

Is that a product from JHB or some other company?

 

I too, have had ALL my housings done with cermet a on the sides and cermet b on the rotor housings. I was planning on having it all back together this month and now I find this thread! Please give some background info about your picture.
From the research I've done, cermet coatings DO have heat resisting properties, are much wear resistant than the iron istself,and even have self lubricating properties should something begin to overheat or loose lubrication.

I'm sure everyone has seen a news flash or two of the safe return of the Discovery space shuttle & crew. Guess what NASA uses in the heat tiles...
A ceramic based formula! NASA has even done ther own research with rotary engines!!! I found a NASA article about how THEY had done their own testing with a cermet coating called ps200 in a rotary snowmobile engine! They even claimed to have developed an even better coating (ps300) which they believe would allow an engine to be run WITHOUT lubrication! It turns out they already have ps200 being used in production in Moller Internation's "Freedom Motors". (Which are a rotary engine design!): http://www.sti.nasa.gov/tto/spinoff2001/t2.html http://www.moller.com/

And I just found these other links.(NASA's still not finished with cermets yet!)

http://www.grc.nasa.gov/WWW/epbranch...CermetCoatings

This very good link for those who have no idea what or where cermet comes from, where it is used, and where it WILL be used in the future:

http://www.newi.ac.uk/buckleyc/ceramics.htm

Just do some searching on your own. There is a ton of info about cermets out there!

I have now laid out my position on cermet coatings, backed up with SOLID proof.
If there are problems with the cermet coatings being used and sold by JHB, Why are they still in business? Why would the Mazda 787b race car use cermet coated internals if the coatings wear out prematurely, leaving bits and pices to grind up the engine? (I'm sure I've read/heard elswere, that if a piece of cermet ever was to be chiped off, it would turn back to dust. But don't take my word for it.)

http://www.answers.com/topic/mazda-787

I would definitely like to see/read proof that the cermet coating is no good, because everything I've read/seen has been good news.


Trueblue707


Go ahead and flame away all you want...I want to be proven wrong, so I can get a refund from JHB. LOL

 

Tim really should have come into this thread with the full story. I think he really just doesn't want it to be his fault. He got out-of-spec housings back from JHB from a bad run, and instead of sending them back to JHB (which they offered because they'd already f-ed up his order) he sent them somewhere else to have it ground down. From my knowledge I'm pretty sure that the whole reason scalliwag was working on the armacor coating was that nothing else had the level of build up that it does, which would make me think that when tim had them re-ground he was grinding away at something thinner than he should have been. Noone to my knowledge that has gotten in-spec housings back from JHB has had the type of problems tim did having them reground. I believe the only way to have gotten his housings back to spec, would be to grind past the coating, and re-spray, which is the process for application in the first place.

 

I had my housings reground elsewhere to original spec,so there would have been 0.19mm of cermet on the steel liner. JHB say the finish is very important,and my housings were finished much smoother than they were from JHB.Considering that,there is still no way it should have worn off in 700 miles.I know the engine could have carried on running for 1000's of miles on the steel liner alone,but I stripped it after it started to lose power on the dyno.Most of the cermet had gone,in little bits,scoring absolutely everything.
What concerned me was before I built the engine the cermet did not appear very hard,not as hard as the original chrome.
I have now had the housings ground back to the steel liner,they are to spec,but there are a few lines of cermet still there where the original grinding by JHB was not accurate enough.Next coating?

 

I'm certainly no expert, but I always look suspiciously at new materials to be used in the engine. Recall that when Mazda was developing the engine they needed to find the right material to use for both the housings and the apex seals. Too hard of one caused damage the other. Too soft of one ment less life for itself. Logically using a new material would stand a high chance at throwing the balance out of wack.

The other property to consider with the housings is that they are designed to have microscopic pores to allow oil to stick to it. If the surface is too slick then the engine doesn't have proper lubrication.

As for use in F1 cars, R26B and Nascar, that doesn't give any indication if the material is appropriate for long term street use.

Side note: That link on the 787B had new info for me. I didn't realize that the R26B made 930hp @ 10.5k. Given their pace going into the '91 race, obviously they couldn't make it reliable enough to push beyond 9k.

 

a couple of issues with your claims here.

first-how can you take a product, change that product by grounding it down and expect it to still be what it was originally intended to be. You screwed it up. JHB offered to warranty that part for you if you sent it back, instead you went out on your own and modified it.

second-that plate you link a pic to isnt even coated with cermet, that is a stock plate, the housing was coated and than modified without JHB processes.

third-what spec are you referring to? ALso what means of measuring the smoothness are you using, an RA measurement? If so, the number you mentioned in the other thread is totally wrong. How did you measure them?

finally, I have probably more experience building with JHB's parts than anyone else, I have taken a motor apart after roughly 4500kms, after someone horribly messed with the timing and popped 5 out of 6 apex seals. The plates were perfect, all indications of a motor that was just fully broken in. There was no flaking or chipping like you claimed, and this was after a catastrophic failure. The plates went back in with cermet housings and is now making 120 in the rear and 110 in the front after another 1500 on the rebuild.

This all leads me to beleive that the parts work just fine, and the reason yours failed, and if it did chip off or whatever, it is because you modified the part. You totally changed al the properties that were originally intended to be there. Do you not think that the coating is applied to a certain thickness for a reason, and not to be ground down past that. Also, I know JHB uses very specific processes to achieve thier finished surface, unless you know exactly what they are, you have no bussiness messing with what was there. If you didnt like the part, you were offered to be compensated with a new one after they cleared up the tolerance issue. I beleive you screwed up the part and that is why you had the problems.

I will continue to use their parts in rebuilds not only because they are a superior product in every aspect to chrome, but they are also cheaper than new housings.

 

That is what is so cool about the cermet coating. It is very hard, but has less friction than crhome. Thus, it mantains and even betters the "balance" of the engine as you called it.
I understand your position. I was very scepticall/cautious when I found out about this stuff.

Someone mentioned Scaliwag's cool project of armorcoating housings. I realy hope he can get it to work. We need more people like him. If you have the time, I recomend you read Scaliwag's thread.
https://www.rx7club.com/showthread.p...2&page=1&pp=15
Mark from JHB even bumped in there with some of the test data and pics of JHB's cermet housings. (Pg. 40+)

I haven't heard of anyone else having a failure besides Tim. His case is obviously canceld out by the fact that he altered the coating by grinding and refinishing it.

I did have a small problem with JHB. They sent me S5 rotor housings instead of S4's. They readily gave me the option to have them exchanged for free, but after some consideration I decided to keep them. If it turns out that I have issues with the S4 internals and computer not working with the S5 housings properly(which I am 98.5% positive they will work fine together), then that will be my fault because I decided to keep them.

The only alterations that I will be performing on my housings are oil gallery mods, polishing out ports, and making sure the edges of ALL the ports have a nice smooth radius into the working chamber. I don't plan on ever needing to rebuild this engine ever again, as this will be a bi-weekly driver and only autoxed now and then. If I do take it apart, it will be for porting and ceramic epex seals.

Soon, there will be cermet engined 7's showing up in various places, expelling the doubt about the cermets's abilities.
It's all just a mater of time. Ceramic seals have proven their selves time and time again. Hopefully soon, cermet coatings will be given the recognition they deserve as well.

wpgrexx,
Sorry for getting off topic. This thread was about your compression tests. I like those numbers. I'd like to see that kind of compression in my 13b cermet engine. Any tips/tricks I should know before I stack my motor?

Thanks, Trueblue707

 

just make sure you have all internal surfaces nice and flat and use new seals. Basically I wanted to show that these motors are making great compression and their is nothing wrong with the cermet parts.

 

No,JHB screwed up my new rotor housings.What are you saying,I made the coating softer by having it reground?
The plate wasn,t coated,but totally ruined,it was absolutely perfect 700 miles earlier.
If JHB had said the coating was thicker for a reason,then fair enough,but they promised my housings coated and finished to original spec.,then screwed them up.
They never offered me a new part as compensation as you say,and they refused a refund.I did not trust them with my housings again,so that is why they didn't go back.
I had them ground so my rotors would have the necessary clearance.Did you check any that you built?
Are you associated with JHB?

 

You can go to Mazda in Hiroshima and see the ceramic coated parts on display.....
The main difference I think is the mazda parts were not previously chromed or nitrided then coated, the mazda parts were virgin metal with no oil embedded in the pores or grain of the metal. I dont know what prep JHB does to the parts prior to coating, but I would think it would have to be contaminate free before coating, I dont think the coating would stick to the chrome or traces of chroming, or metal that is contaminated with oil residues..
The mazda parts were most likely covered with a much thicker layer and then cut to spec..Max

 

Great! I cant wait to hear how the other engines do. With my puttering around I should have my engine up and running in a couple (or more) months with compression numbers. I realy wish I could find the right 7 for it. It came from an SE automatic with power steering. I do have an '86 SE from wich I was going to get the manual steering rack and parts to make the '88 into a standard. Its going to be alot of extra work, but I'll do it if I have to. Why couldn't Mazda just put both standard and automatic transmission mounts on every model?...lol



Mark told me the side housings are ground flat which I asume would remove the nitrating, then coated and lapped down to spec. I can't remember what the target thickness for the coating is suposed to be, but I do remember he said it was six or seven times the required amount to last the normal lifespan of the engine. The process for the rotor housings is a little different. I believe all of the chrome gets removed to expose the inner ribbed steel sleeve before coating, and then ground/finished back to speck. I'm not quite sure how its done, maybe they disolve the crhome out of the ribbed sleeve with a chemical proces? Whatever they do, he said as long as the wear/damage dosen't go through the crhome, the housings are still usable.

The only afiliation I have with JHB is as a customer.

I wish Mark could find the time to start a thread on the cermet specs and testing data. Then everyone would get all the facts from the source, and not from hearsay. From what he's told me, they are keeping real busy filling orders. He said many orders are from dealers and are whole pallets of housings! I believe him because it took six months to get my housings back. I just had to have MY housings...

Once again, sorry for taking this of topic. At least the word about cermets is getting out. Litle by litle...

 

My housings were new,so would have been contaminate free.If the coating needs to be thicker,and I made mine too thin by having it reground,then JHB are not doing any housings to spec. They told me they remove all the chrome,0.19mm when new,then apply the coating,then grind it back to spec.
Maybe the cermet was affected by fuel,I say this because the coating had worn off more from between the inlet and the plug area.Is this a possibility?

 

it is my understanding that you were told do whatever you want since you said you could do a better finish and they were you parts. After they were screwed up I beleive he offered you to send them back if you paid theoutstanding balance, you never replied back to him after that. He offered to rectify the situation above and beyond what is normally covered. Basically fix the part that you screwed up. I know he said he was having tolereance issues back then, and told you the same thing, which is why he offered to take them back for a new set of housings for you.

Am I associated with JHB, NO. I have become friends with Marc through buying his parts because I build engines and need a good supply of housings. Cermet is the best option.

 

More crap that just isn't true.Fact is the cermet came off,should never have happened.My housings left JHB useless for what I wanted them for,should never have happened.