Cermet Housings? Worth it or not?
Thread Starter
Wrkn Toyota, Rootn Wankel
Joined: Sep 2007
Posts: 1,642
Likes: 1
From: "Haystack" Hayward, CA
Cermet Housings? Worth it or not?
I've seen some members saying that the JHB Cermet Coated Rotor Housings were a raw deal and worth crap... 
I haven't tried it myself... but I am very interested in the idea of getting them in the future for an engine build.
So I figured, let this be a place that we can post our opinions and experiences with the Cermet or coated housings?
You know for the better good of all us rotorheads?
I haven't tried it myself... but I am very interested in the idea of getting them in the future for an engine build.
So I figured, let this be a place that we can post our opinions and experiences with the Cermet or coated housings?
You know for the better good of all us rotorheads?
Joined: Apr 2005
Posts: 212
Likes: 0
From: Thunder Bay, Ontario
I had a 12a 1/2 bridge done with cermet b. engine needed to be torn down at 10k km due to coolant loss(not related to cermet coating, a pinched oring -it was built poorly and it will be the last rebuild That I buy, know i have the tools and the knowledge and experience with rebuilding), never reasembled because of major flaking of the cermet in both housings, from my one experience I would not get them coated again. I hope this was just my experience with the stuff. I had it chose to go cermet after doing resaerch that pointed to it being a good choice.
Thread Starter
Wrkn Toyota, Rootn Wankel
Joined: Sep 2007
Posts: 1,642
Likes: 1
From: "Haystack" Hayward, CA
Just deciding to bump this thread because I never really got all the information I was looking for and I was wondering if Xlr8 had any updates...
so if you guys have any input on the benifits or downsides of cermet housings please post!
so if you guys have any input on the benifits or downsides of cermet housings please post!
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djessence
Joined: Aug 2007
Posts: 2,063
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From: Alberta, Canada
I will step in with opinions and heresay.
Firstly WHY do you want cermet housings. They are expensive and from looking around the longevity seems to be a HUGE issue.
Mazda designed their housings out of specific materials and did a dam fine job IMO.
I would think you would better spend less money by buying new housings directly from Mazda. But this is just me.
Alot of guys with various engine configs run high rpm, high boost, thrash their engines to **** and still the mazda components hold up decently well. I think they speak for themselves, where as the cermet coated ones do not.
Firstly WHY do you want cermet housings. They are expensive and from looking around the longevity seems to be a HUGE issue.
Mazda designed their housings out of specific materials and did a dam fine job IMO.
I would think you would better spend less money by buying new housings directly from Mazda. But this is just me.
Alot of guys with various engine configs run high rpm, high boost, thrash their engines to **** and still the mazda components hold up decently well. I think they speak for themselves, where as the cermet coated ones do not.
Full Member
Joined: Mar 2008
Posts: 55
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From: Indiana
i've been reading around about people's experiences with the jhb coatings and this is the trend i'm seeing:
12a housings that are coated have some rate of flaking and make some very upset 12a costumers of the coatings
however, 13b and 13b rew housings that are coated do very well and make a lot of customers very happy.
so here's my educated guess on the whole "is cermet good or bad" topic:
to my knowledge 12a housings are aluminum and 13b rew housings are iron. aluminum expands much more than cast iron at higher temperatures. cermet is very hard but brittle too. so it's possible that:
aluminum coated housings are much more likely to "flake" especially when their owners run into coolant problems like Clearkut's did.
cast iron coated housings are less likely to "flake" because cast iron doesn't expand much, even when its overheated, so 13b rew coatings have a much lower frequency of "flaking"
in fact, the only instances of flaking i have read about were from 12a housings. another thing to note is that i have only read about flaking issues from cermet b coatings not cermet a or x coatings.
again, this conclusion is derived only from extensive searching.. i have no first hand experience with the stuff and could be wrong.
if anyone has any experience or evidence to prove otherwise, PLEASE SHARE IT! i am looking into getting coated 13b coated housings myself but waiting to hear from more ppl's experiences.
12a housings that are coated have some rate of flaking and make some very upset 12a costumers of the coatings
however, 13b and 13b rew housings that are coated do very well and make a lot of customers very happy.
so here's my educated guess on the whole "is cermet good or bad" topic:
to my knowledge 12a housings are aluminum and 13b rew housings are iron. aluminum expands much more than cast iron at higher temperatures. cermet is very hard but brittle too. so it's possible that:
aluminum coated housings are much more likely to "flake" especially when their owners run into coolant problems like Clearkut's did.
cast iron coated housings are less likely to "flake" because cast iron doesn't expand much, even when its overheated, so 13b rew coatings have a much lower frequency of "flaking"
in fact, the only instances of flaking i have read about were from 12a housings. another thing to note is that i have only read about flaking issues from cermet b coatings not cermet a or x coatings.
again, this conclusion is derived only from extensive searching.. i have no first hand experience with the stuff and could be wrong.
if anyone has any experience or evidence to prove otherwise, PLEASE SHARE IT! i am looking into getting coated 13b coated housings myself but waiting to hear from more ppl's experiences.
Thread Starter
Wrkn Toyota, Rootn Wankel
Joined: Sep 2007
Posts: 1,642
Likes: 1
From: "Haystack" Hayward, CA
Yeah, I am looking more for 13B applications... particularly the Renesis, but I think that the housings are the same material as other 13B's...
This is mostly research for a future swap I am working on. I heard both good and bad about cermet coatings so I was curious what the deal was.
This is mostly research for a future swap I am working on. I heard both good and bad about cermet coatings so I was curious what the deal was.
Thread Starter
Wrkn Toyota, Rootn Wankel
Joined: Sep 2007
Posts: 1,642
Likes: 1
From: "Haystack" Hayward, CA
From what I remember reading about the Rotor housings... They are constructed out of aluminium and then have a steel insert that is "cast" into the inner part of the housing which is then coated in chrome.
I am not familiar with 13B housings though...
I am not familiar with 13B housings though...
Respecognize!
Joined: Sep 2004
Posts: 4,106
Likes: 72
From: Anchor Bay, CA
i've been reading around about people's experiences with the jhb coatings and this is the trend i'm seeing:
12a housings that are coated have some rate of flaking and make some very upset 12a costumers of the coatings
however, 13b and 13b rew housings that are coated do very well and make a lot of customers very happy.
so here's my educated guess on the whole "is cermet good or bad" topic:
to my knowledge 12a housings are aluminum and 13b rew housings are iron. aluminum expands much more than cast iron at higher temperatures. cermet is very hard but brittle too. so it's possible that:
aluminum coated housings are much more likely to "flake" especially when their owners run into coolant problems like Clearkut's did.
cast iron coated housings are less likely to "flake" because cast iron doesn't expand much, even when its overheated, so 13b rew coatings have a much lower frequency of "flaking"
in fact, the only instances of flaking i have read about were from 12a housings. another thing to note is that i have only read about flaking issues from cermet b coatings not cermet a or x coatings.
again, this conclusion is derived only from extensive searching.. i have no first hand experience with the stuff and could be wrong.
if anyone has any experience or evidence to prove otherwise, PLEASE SHARE IT! i am looking into getting coated 13b coated housings myself but waiting to hear from more ppl's experiences.
12a housings that are coated have some rate of flaking and make some very upset 12a costumers of the coatings
however, 13b and 13b rew housings that are coated do very well and make a lot of customers very happy.
so here's my educated guess on the whole "is cermet good or bad" topic:
to my knowledge 12a housings are aluminum and 13b rew housings are iron. aluminum expands much more than cast iron at higher temperatures. cermet is very hard but brittle too. so it's possible that:
aluminum coated housings are much more likely to "flake" especially when their owners run into coolant problems like Clearkut's did.
cast iron coated housings are less likely to "flake" because cast iron doesn't expand much, even when its overheated, so 13b rew coatings have a much lower frequency of "flaking"
in fact, the only instances of flaking i have read about were from 12a housings. another thing to note is that i have only read about flaking issues from cermet b coatings not cermet a or x coatings.
again, this conclusion is derived only from extensive searching.. i have no first hand experience with the stuff and could be wrong.
if anyone has any experience or evidence to prove otherwise, PLEASE SHARE IT! i am looking into getting coated 13b coated housings myself but waiting to hear from more ppl's experiences.
some peoples kids man...*sigh*
Full Member
Joined: Mar 2008
Posts: 55
Likes: 0
From: Indiana
however, the theory behind why cermet coatings might "flake" is the same... if the aluminum housings get too hot they will expand more than the coatings making the coatings flake.
also, i've heard that stock chrome lining "flakes" too. so those of you who have had cermet flake, have you run stock housings in the same conditions (i.e. coolant loss and overheating conditions, etc.) to know if cermet coatings are any worse than stock linings?
