RotowarySwamp

So I'm new to the world of rotary engines and just bought a 1983 rx-7 last spring. The car is in excellent shape aside from the paint which is reasonable... and a so so interior. After deciding that I wanted to keep it and learn about rotary engines and I have a basic understanding of them now, I want to know if its worth keeping the 12a in there or get a rebuilt 13b. I want more power but not sure if its cost effective to put work into the stock motor? I plan to work on building this car over the next few years and would really appreciate some input on motor swaps, differentials (could I use the stock one with a 13b?)etc. etc.

diabolical1

iTrader: (3)

welcome to the board. glad to see another Gen I guy in the making.

is it worth keeping the 12A?

you may not want to hear this answer, but it's totally up to you. only you know what you ultimately want from the car. only you know how far you're willing to go.

12As and 12A hard parts (rotors and housings) are finite now and that fact must be reckoned with when making plans. don't get me wrong, there are still options available to keep your 12A going for years to come though.

putting a 13B in is easy enough and you even have 13B-MSPs as a different twist on that option. unless you plan extreme uses, your tranny can remain in place. only change that may become necessary would be going with a GSL rear if you don't already have one.

RotowarySwamp

Thanks for the input... after doing a little research on the availability of certain 12a parts it seems like a 13b is the best option for me mainly due to the fact I live in the middle of nowhere and would rather have an engine that has abit more parts available. More than likely I'll get a rear diff thats mated to a similar year 13b since this is going to be more of a fast cruiser for me and my dad until he's to old to drive it. And now for a question that i think was already answered but I could use a little more detail... will that bell housing from my stock 83's transmission fit on any 13b or are there certain ones that won't fit? I probably just a dumb question but oh well... haaha

misterstyx69

iTrader: (142)

Personally Would not try altering anything that is working.
Ya,it is nice to have power,but if you are going to take out a perfectly good power plant,then it leads me to wonder WHY kill a working car?
Do you have a Daily driver?It is in your budget to have the car down while you tinker on it?
Personally I would drive it,have a little fun with what you have.
In the meantime you have a car that you can drive..then you can start collecting parts for the swap you intend on doing.Save this for a "rainy day" project.All parts at hand,just go nuts.Get it done quick and easy.
But taking a car that drives just fine and ripping the heart out of it is like wiping before you poop!!...it doesn't make sense!

diabolical1

iTrader: (3)

all Mazda rotaries have the same bell housing bolt pattern from the 10A up to the 13B-MSP.

if you don't already have LSD in your car, then just get a GSL rear. the GSL-SE is also a bolt-on option, but you'll have to do more work to get the front hubs and brake parts to have a uniform wheel bolt pattern on the car.

Aaron Cake

iTrader: (1)

But it's not just a bellhousing issue. You'll need a GSL-SE front crossmember and GSL-SE oil pan at the least.

And depending on the engine you will need at the very least to replace the manifold and carb. Or better yet, since almost all 13Bs are fuel injected, convert to fuel injection.

Why swap out the 12A if it's working just fine for you?

RotowarySwamp

I already have an everyday driver its a 08 Subaru impreza and of need be I have a truck at my disposal too. I can see that people for already saying I'm off my rocker for taking out a perfectly good engine and dropping in another but I have my reasons haaha I'm going to take out the 12a and have a shop refurbish it along with the stock tranny since I have found a bunch of 13b's with tannys with them. I plan too keep the 12a as stock as possible and use a 13b as my training motor, I'd feel bad if I messed up such an old rotary that's got 110,000 miles on it and is still going strong.

RotowarySwamp

... OK scratch plan A... I found two parts cars, ones an 85 with a 12a in it that runs but won't drive... and its auto eww. The other I have no clue what engines in it but its blown, transmission is good though. I should be able to get ahold of enough parts to keep the 12a running for awhile... with a spare rotor or two and housings just in case.