Well I decided that over the summer I will take my engine out and rebuild it since I would like to restore my car to the best of my abilities. I have already done the bodywork, paint, some electrical (fusible link problems), full engine tune-up (spark plugs, air, oil, and fuel filter, coils, spark plug wires, battery, alternator, starter, belts, rebuilt carb, changed fluids, ran new fuel lines), new tires, had the wheels remachined and painted and a full brake job. So now its time for engine internals. What I would like to do is buy a new set of rotors, rotor housings, rotor kit, gasket set, front and rear seals, and pilot bearing. I think I can do this rebuild for under $3000 cdn. Is my guess correct? (Factor in shipping cuz i live in southwestern ontario.) Is there anything that I am missing that I should do since the engine is out of my car? Any input would appreciated. Thanks.

 

www.banzairacing.net

check atkins...im not sure if they do 12A though.

 

Is there any reason for rebuilding it or do you just want to start off fresh? If there is no reason, don't bother, when its time then go for it. Atkins does sell the 12a rebuild kit, just hard to find on site.

 

wtf is $3000 cdn?!
im too lazy to do the conversion.
new rotors are probably not necessary, 12a rotors are extremely durable.
what year/model car are you working on?

 

given the fact that the motor is still in use, you probably won't need rotors. i have not come across any 12A that i've disassembled to have rotor that are out of spec - only rotors that have suffered physical trauma.

you will want to buy all seals and springs new. upgrade where possible, even for only a straight rebuild (race bearings, REW corner springs, REW ROPR & FOPR spring, etc.). definitely upgrade if you plan on any porting!

as for the rotor housings, get new ones if you can, but i thought i read that they were discontinued. maybe someone else can confirm or correct this?

 

upgrade the oil pump to a gsl-se

 

They were. In my search for a new 12A, I kept reading this and praying my 12A was fine.

 

[QUOTE
what year/model car are you working on?[/QUOTE]

an 82.
http://www.mazdatrix.com/b1.htm
you can still get the 81-85 12A housings.
I just wanted to build the engine with new parts so I would not have problems down the road (compresson).
When I take it apart I will go from there. does anybody have a mazda workshop manual for for sale??
thx guys

 

I have all the parts in stock and ready to ship.. When you are ready let me knoiw ant I will do my best on the prices...

Dan

 

Oh yeah you can get them, I think Mazda quit making them.

 

Thanks. I’ll be in touch when im ready 2 start the build. Thanks for all the input guys.

 

fyi- dan has a new type of corner seal that he is making... i would also suggest using the rx8's corner seal springs, or third gen will work fine as well... my 2 cents

 

I've found that 12A rotor housings usually have flaked chrome. This flaking can only become worse (My last high-mileage 12A teardown found that the almost complete loss of compression in the rear rotor was due to scads of chrome flaked off in critical areas).

For this reason I intend to replace both rotor housings with new ones, even though the front housing only has a small bit of flaking, about 1/4" long by 1/8" in from the edge.

On the other hand, the rotors are fine and the irons have very little wear. The factory nitriding and machining marks are still very visible on the wear surfaces. All seals are worn, but still very functional thanks to years of regular oil changes and running a separate supply of two-cycle oil fed to the metering pump. (The stuff from the oil pan was blocked off via an aluminum plate bolted between the front cover and the pump body). Still, all seals and thrust bearings/ plates/ spacers will be replaced with new ones.

As for pricing, check out Mazdatrix's website. They sell a variety of new 12A components--- at least those that are still available from Mazda. But if you buy from them it's best to arrange for shipping via some other entity than UPS, Mazdatrix's courier of choice--- unless you want to get financially ***-raped for brokerage fees.