These housing are out of a 'blown' motor that I got for free




This one here has some chrome missing on the exhaust side of the housing.... Can I still use this? will it backfire? The housings seem to be mint, except for the little flaking,

 

by mazda specs they rec replacement,but on the other hand i've seen people use worse housings for race engines! personally i wouldn't on my daily driven car.




93 fd 13.5@101.38 mph

87tII soon to be racing

 

I'll tell you what, I've seen alot worse. I have 4 (2 motors) and the best of the bunch is probably worse than those.
The second one looks ok, but the first one is probably marginal. that chatter spot looks kinda rough.
Not only do you have to consider flaking and chrome left, you also have to make sure the housings haven't been warped. there is a good description on how to check this in the RX-7 Haynes manual.
I see those are 12A housings, so they most likely havne't been turboed which usually causes more damage when it breaks.

 

I've only done a quick cleaning on the housings, I took them out a few hours ago.. the mark I think you're talking about is just a rust mark, it rubs right off... I guess probably the best thing to do is to take them to a local rotary shop and have them look at it.

 

the only reason why i don't rec using a housing with the chrome missing is because i had a 12a that seized,so i took it apart and found tha apex seal had embedded itself in the housing where a piece of the chrome rim had chipped off locking up the engine.


93fd 13.5@101 mph

87tII soon to be racing

 

from my understanding the chrome is what gets rid of the friction, If I were you I wouldn't use the one missing chrome, just look for another housing if you can find one.

I think the best way to go when rebuilding an engine is that when you have enough cash, buy all new housings and rotors