well, cracked open the ol' 12A today. It ran fine, but smoked at high rpm's and at startup. The rear housing looks trashed, but it ran fine, so maybe I could reuse it? I'm just afraid of more chrome flaking off. Pics are attached. The rear one is the worser of the two.

front:



rear


Now, I'm looking into places where I can get new ones. I cant find anyone that sells 79 rotor housings though. Atkins sells new 81-85 housings for about $410 a pop, and mazdatrix sells them for a bit cheaper. Can the 79 housings be changed for the later ones, or are they some differences that make them incompatible?

Or should I just put in the new seals and hope for the best? How long would it last? It ran perfect before, but for how long?

Tell me whatcha think, I have a spare housing that looks like the better of the two, but it's a front, and the real bad one is a rear.

p.s., if ya got some let me know.

 

79-80 rotor housings are NLA. mazda does still offer em as a reman.

 

I wouldnt reuse any of them.

Im not sure how that thing still worked!

Smoking has nothing to do with housing surface. Its all about oil control rings, orings and iron surface condition.

79/80 was a bit different around the spark plug area

 

Put you up a want to buy ad in the for sale section, if your gonna rebuild, aint no point in using crappy parts.

Try to get a good deal on them, but as a wise old man told me once.

"There is no wrong price, for the right part" Words to live by with a rotary!

 

The front one could still be used, but the rear is thrashed. Bet comp was low on it.

 

I wouldn't use either of them.

Front and rear housings are interchangeable btw.

 

rear is hosed

front is usable; most used ones you'll find will be that quality or worse. i said most.

if u wanna keep the car for a long time buy used or you could just try your luck at a junkyard motor.

 

yes, I definetly want to do this build right. So the rear one is out.

any places to find new housings other than the ones i mentioned?

So the front and rear are interchangable?

How about interchangability between 81-85 rotor housings and 79 ones? Mazdatrix sells them seperatly.

thanks for the input so far

 

Don't quote me on this, but I *think* if you use both housings (front and rear) from the 81-85 years you'll be okay. I don't believe the dowell pins or anything are in different places... it would just be some change of spark plug hole size/position and possibly some coolant passageways not lining up *perfectly*... the coolant rings would be the same so you wouldn't leak and since the dowell pins are in the same place it would bolt together.

But as I said, I'm not 100% certain on all that.. maybe someone could back me up. (or shoot me down, either way)

Jon

 

the later 12a will work but if your going to spend the money on housings just spend some more and build a 13b 4 port using gslse rotor housings

 

Are the 79 housings interchangable from front to rear? Because I have an engine that came out of an 84, but the ridge around the spark plug would suggest that it is from a 79, along with a couple of other things. It was a front housing, but would it work as a rear? It has about the same wear as the front pic I posted.

But then again, I do want to build this up right, and maybe spending $800 on new housings is the right way to go?