Effen wow! why? what's to become of the 12a? 13b run's the show now..i could not believe it. I went to Mazdatrix today to pick up some shtuff and i asked about the New/Reman 12a Rotor Housing's and they said that there no longer in production..i was like..."Wat!!" then i asked "So what does that mean..? No more 12a's?" and they were like "yep.."

Anyway..it suck's that 12a's are going to start dissappering slowly. I'm a big fan of the 12a if you could not tell..Just thought i would share that with the other fan's.

:AA:

 

I have a brand new unused set I brought about 5 years or so ago. I hope I don't have to use them.

 

Yes, It sucks. Mazda quits making the 12A housings, and the price of the 13B housings go up. What the hell?

 

You could always find 13b housing with flaking on the edge and have them shaved down i think 5mm on each side to make them the size of a 12A. They will be like new again and also have a bigger exhaust port than the normal 12A ; )

 

can you do that?? i saw a thread about doing this..but he never updated the thread. got any more info on doing this?

:AA:

 

Truthfully im not sure. I know its been done a few times before with out a problem. Im sure it can be done right again with the proper mill and a expert machinist.

 

i am a machinist/grinder..i going to try and figure something out.

:AA:

 

Thats awesome. If you go through with it please make a thread and keep us updated. - Nick

 

the hard part about machining down 13b housings will be the fact that 12a's had the coolant o-ring grooves machined into the housings, you would have to use later 13b irons that had the o-ring grooves machined into them instead. so it will still be some kinda frankenstein motor. although, other than the length of the motor, everything would appear to be a 13b externally

 

And then good luck getting a manifold, or an e-shaft, to fit...

 

13B housings shaved done to a 12A will take a 12A e-shaft no problem i would assume. Can you please explain to me why you would have a problem with a 12a e-shaft and 13b shaved down housings? I understand the intake manifold may not align up properly to the intake ports on the plates so it may need to be custom but the shaft should be fine. Really would like to know this. Everyday i learn so much on this forum and i plan it to keep happening.

 

www.jhbperformance.com for Ceramic coated housings

I've never used them but last time I checked the price was right. If they can do what they say then the lack of new housings isn't a death sentence to the 12A

I personally can't see triming 13B housings as much af a solution but maybe with a CNC machine and some fast proto typing equipment.

 

junk gsl-se housings maybe? i dont know..

yeah, i forgot about this..they can regrind the chrome and make it like new. i would love to see the process..there price is 150 each rotor housing..


:AA:

 

Or you could just build a 13B instead. Problem solved.

 

that's what i was gonna say lol.....i love 12a but i guess they're forcing us to do engine swaps so we can stop complaining about the cold starts lol

 

Machine down 2nd gen 13b housings, use TII plates. You'll basically have a streetported 12a without touching the ports.

 

I would purchase 13b housings ground down to 12a, modified coolant passages. I am also a fan of the 12a for a few reasons...

 

shouldn't be a problem machining down 13b housings to be used as 12a. just have to remember that both sides of the housing have to be machined equally to keep the intake mounting stud and exhaust port symmetrically centered so the intake and header will bolt up with no issues. pre 86 housings will need the seal grooves re-milled but 86 and later would actually be less work. finding a good usable 12a eshaft and rotors would be the next issue.

 

i still cant believe this, old school head's dont want to swap to 13b. if you keep the housing's to the same spec as the 12a then there should be no problem as far as fitment go's. as for the coolant seal's? ...

:AA:

 

79-85 are old school?

 

i consider pre-79 old school. but i guess anything over 20 yrs old could be considered old school.

 

thats what the toyota and datsun owners said

 

wacky, anything created before my time is "old school.." to me.

:AA:

 

well for now its not bad but i will get rough soon enough.. there are those of us who race these things and have to run 12a motors so once they start getting rare we wil have to fiugre out what to do.

 

So acid, just Model A's?






j/p