gio64

iTrader: (1)

Hi everyone.
I have already read what I could on the cermet coatings done by JHB.
I have also bothered some of you on the forum that I heard had some experience with it and others that I know are knowledgeable on the rotary in general.
I seem to get mixed reviews, so here's a thread I hope can shed some new light on the subject.

I know what follows:
JHB had some quality problems with their entry level coating in relation to the cross flatness of the rotor housings.
This problem doesn't seem to be present in the higher (B and X i believe) quality coatings.

They have several papers that go into detail to explain what cermet is, what its characteristics are, what are the advantages (claimed) over stock plating, what is the process of removal, application and what not.

Now, putting aside one or two people that answered my PMs and told me they tried them and they were happy with them, I have heard several people suggesting that it's better to get a new housing from Mazda and go with that.

Now, does anyone have any evidence of this?
Alternatively, does anybody have a logical-engineering driven reasoning that can at least explain if there is anything to beware of with cermet and why?

Please understand, I am thinking about building an engine and based on what I have read about these coatings and what I have read about the Mazda OEM plating/coating, I don't see why an OEM should be better than this.
Now, my objective here is to simply gather everyone's thoughts, experience and intelligence, to see if some light can be shed on this one.
I don't have anything to do with JHB, I am simply attempting to get a clear panoramic picture of what's out there so that -when I go on and build- I make an informed decision. Collateral would be to leave some informative discussion for all those who would be interested in the same stuff.
Thank you and -before I close- I have gone through all the threads this forum has that I could find.
I would like to invite everyone to stick to facts or engineering opinions based on known facts.
I hope this is going to be a constructive discussion for those who'd like to participate.

WaLieN

http://www.jhbperformance.com/products.php

The "lowest" line of the coating is the Cermet B coating. The only issues I've personally heard of are supposedly from shipping errors, which caused the edges of the housing coating to be chipped.

gio64

iTrader: (1)

You're right.
I am sorry, I have been back and forth from that site, some confusion occurred.

Do you have any other info or personal experience?
I have received some negative opinions and I am just trying to understand why.

I am sure nobody here has run an engine for 200k miles with and another without, then opened them and found out whatever.
I am just hoping somebody with the right knowledge can step in and put things in perspective...

Thanks for your input, I appreciate it.

Mahjik

iTrader: (1)

https://www.rx7club.com/rotary-car-performance-77/resurfacing-rotor-housings-111142/

https://www.rx7club.com/rotary-car-performance-77/some-cermet-engine-results-451815/

https://www.rx7club.com/rotary-car-performance-77/plasma-cement-ceramic-coatings-first-impressions-389435/

https://www.rx7club.com/rotary-car-performance-77/plasma-cement-ceramic-coatings-787b-383503/

Prometheus

iTrader: (2)

I thought about running cermet coated housings/ rotors with hurley seals...

still looking into that.

thanks for all the great links

charlies7

iTrader: (4)

^^^ I wouldnt recommend hurley seals..

SLOASFK

iTrader: (5)

Everything I've read screams "STAY THE **** AWAY!"

https://www.rx7club.com/bad-fugly-members-185/jhb-performance-poor-quality-poor-communication-608589/
https://www.rx7club.com/showthread.p...66#post7342066

Taken from the second link:



I wouldn't trust them.

ScrappyDoo

iTrader: (7)

If you haven't already I would read the below thread. It has lots of discussion about coatings in general.

https://www.rx7club.com/showthread.p...lasma+coatings

I used JHB for about 8-9k in my TII before I sold the engine. I have not heard from the new engine owner but I am assuming he has not had any problems. Unfortunately I cannot assist you in your desire for technical answers.

Prometheus

iTrader: (2)

I have not read the links, and my statement was just a thought that I have not looked into.

Thanks to everyone who expressed their concern, but I'm still going to look into it myself.

+1 on having a kick *** community.

gio64

iTrader: (1)

First off, thanks to all the contributions.
Mahjik, thank you for the links. I had actually come across your posting links on this matter already and I believe I had certainly read all but one and possibly that one as well (not 100% sure).

I am still puzzled.
On one hand, lots of complaints, on the other, lots of good results...
The biggest problem I'm having is certainly to understand whether or not they have improved overall in the recent time and also, whether or not attempt to use their service...
Any substantial number of long-time users that can testify one way or another?