RotorMotorDriver

iTrader: (1)

I've been looking for an engine for my 83 GSL, and I just came across a 79 that "runs and drives good" but it "needs a clutch master or slave cylinder" ?? Anyway, I was always told that only the 12A's from 82-85 would fit in my 83? Is this true? If its not (or if its not too hard to make it fit) I can get the whole car for $200 and get my GSL running with the 79 engine. How does this sound to you guys?

~T.J.

PS - Havent talked to the guy so I dont know too much about the car yet, Ill know more later.

MIKE-P-28

iTrader: (1)

I got one from my 85 12A, that I replaced about 3k miles ago ... Got it from Mazdatrix ...

RotorMotorDriver

iTrader: (1)

Are you saying that you have an engine out of an 85 that is a 12A that you had originally purchased from Mazdatrix that you want to sell? Is that it? Cause if so, I would be interested in buying it as long as it would still run and everything...How many miles are on it?

~T.J.

PS - Im gonna PM you too...I really need an engine

RotorMotorDriver

iTrader: (1)

Ok, back to the original question...how hard is it to put the 79 engine in my 83?

~T.J.

nimrodTT

Pretty much the same as swapping an 83 block into your 83.

RotorMotorDriver

iTrader: (1)

Its the "pretty much" that has me worried...I was told that only the 82-85 would fit, ther has to be a reason for this..right?

~T.J.

peejay

The engine itself will fit great. However you won't be able to use the emissions system from the other engine. The systems are totally different between '78-80 and '81-85.

If you're planning on putting a header on and eliminate the emissions equipment, then there is no problem. You do need to either convert your '83 to an air oil cooler (recommended) or bolt your '83 setup on the '79 (it'll work but the water oil cooler really sucks).

I had an '84-85 engine in my '80. It's a straight bolt-in. To simplify things I put my '80 carb on it because the carb that came with the engine was total garbage. I put a header on at the same time i did the engine swap. I used the '80 air oil cooler and the '80 oil filter pedestal, and threw the beehive cooler far, far away

RotorMotorDriver

iTrader: (1)

That sounds like too much work for me . I was really hoping for something I could just "pop in" and "be done with" . Anyway, I appreciate the info. Also, on another note, I have $300, the '79 was $200. I was thinking I could buy it and pop the engine in cause it "runs and drives", but I havent seen it (I planned on checking it out before I bought it though). My other option, was to try and save some money and buy some parts from some people and rebuild mine or something. And finally, there was a guy that has a 12A from an 85 on thepartstrader.com that I emailed about possibly buying it from him. He wants $500 for the engine. He says it runs, but the car was in a wreck (rear end damage). Anyway, of those options, which would you do?

~T.J.

peejay

It's not too much work... it's all basically stuff that you have to take out and put back in anyway when changing engines.

MIKE-P-28

iTrader: (1)

Sorry man, when I said i had one for sale I was refering to this
But I do have a perfect rebuildable complete core
I know you know, but for anyone else.

I have a complete 12A, everything perfect and cleaned. Intake manifold, carb, dizzy, oil pan everything I'll see for cheap. Just add seals and lap the side housings and you have a NEW MOTOR.

nimrodTT

Why not just buy the 79 for $200 and drive it around while you locate a new engine?

RotorMotorDriver

iTrader: (1)

"needs a clutch master or slave cylinder"

~T.J.

Felix Wankel

And? Thats $40 worth of parts.... Not like it needs a tranny rebuild or anything...

yayarx7

Sounds like a $200 driver to me!

85RX7GS

iTrader: (1)

They are pretty much all swappable. The only difference that you may encounter are little things, such as the oil cooler location, emissions stuff, etc.. Otherwise, the price is right!

RotorMotorDriver

iTrader: (1)

Yeah, I talked to the guy and Im actually going down there tonight to check her out. He also has been driving it around in his field, sounds to me like shes a runner...Maybe I can use the engine after all. I think Im gonna buy the car and tinker with it, if its anything good, I may keep the enigne and use it, if not, Ill part it out or something. He says that "someone" told him that it had a "burnt rotor" because it "pops" while its running...My 85 GSL used to "pop" while running (I posted a few times about this), and I fixed a few vacuum leaks and fixed the timing and now it runs fine. Im hoping that this is the same thing. Anyone need parts??

~T.J.

PS - Anyone ever heard of a "burnt rotor"?? Or could this be slang for something else?? He started it over the phone and it started right up with no choke or anything, so Im hoping its not actually all that bad .

RotorMotorDriver

iTrader: (1)

In theroy, if I drop this engine in my car, what should I be prepared to change? Refresher: 1979 RX-7 GS? donor car, 1983 RX-7 GSL receiving car. I know the ignition will be changed to electronic (anyone know a website I can read?), the oil cooler (website?), and the "emissions" are different...What does the "emissions" difference mean (website)? Can I just strip the 79 engine down to basically nothing and drop in all my stuff? It will at least bolt up to the 83 tranny and motor mounts, right?

~T.J.

peejay

Yes, the engine itself is a straight bolt-in.

To make wiring easier, use your '83 wiring harness. What I did was just remove the positive and negative cables off of the battery and where they attach to the body, unplug the wiring harnesses from the body (the plugs are all under the master cylinder area), and yank the engine/trans as an assembly. Then you bolt the alternator, '83 dizzy, etc all on to the '79 bare block and hook the wiring up.

Don't bother with the emissions, and here's why - the '79 uses a thermal reactor, and the '83 uses a converter. The emissions systems work totally different.

The '79 engine gets its air injected through the shell of the thermal reactor itself (coming from the heat exchanger - no it's not a cat but it looks similar to one) into a port in the rear rotor housing underneath the exhaust port. The ACV diverts air either to the reactor, or to the thermal reactor cooling system (the exit for this is the weird 2nd mini-pipe that runs along the exhaust), or back to the air cleaner.

The '83 engine injects air into the exhaust ports by way of the intake manifold, through the square port underneath the intake ports on the center housing. The ACV switches between injecting to the ports, injecting to the converter, and releasing back to the air cleaner.

Again, the systems work totally different, and the engines themselves are different as far as where exhaust-port air is injected, so you can't convert one way to the other. The simplest thing to do is put a header on it and remove all the smog goodies, and get an ACV block-off plate. (Or, just wait until you can get your hands on another '81-85 12A)

Since you're putting a '79 engine in, you could simply bolt up your '83 manifold to it (the exhaust gasket will block the air port) but UNDER NO CIRCUMSTANCES should you run a catalytic converter without the ACV/solenoid/computer setup - it will die rapidly. Also never run a thermal reactor without the emissions equipment for the same reason.

For simplicity's sake, use your '83 carb, because you know that everything will hook up properly to it. You must also use the '79 intake manifold with the '79 engine, but that's a bonus because the '81-up manifolds are garbage.

The oil cooler is a straight swap... it should be fairly obvious what you have to do when you have both engines out.

Felix Wankel

PJ, are the SA and FB engine braces different? I've heard they are.

RotorMotorDriver

iTrader: (1)

Hmmm...not exactly what I wanted to hear...good info though, thanks man. Im not gonna be able to afford a header after all this stuff, I was just hoping that the "emissions" stuf would just be a matter of a few different things that I could just bolt on and make it work "stock"...I dont wanna have to buy a header and what not for this engine as this one may die on me and then I would have wasted the money on the exhaust stuff...I JUST WANT A RUNNING 12A .

~T.J.

peejay

Felix, I think they are the same. At least, I bolted my FB brace into my SA just fine. If they are different, it would have to be side-to-side engine placement, and I didn't note any kind of alignment issues.

peejay

I should write a differences between SA and FB FAQ. Heck I just wrote half of it up there

Felix Wankel

You're making it sound like a huge ordeal when it isn't.

1. Pull 79 engine

2. Yank thermal reactor and replace with 83 manifold and gasket

3. Stick 83 carb on 79 intake and use 83 solenoid rack (if this is possible)

4. Put 79 air/oil cooler in the 83 car, rerouting the one heater hose that used to feed the water/oil cooler

5. Swap front engine brace (if needed)

6. Stick 83 dizzy in and put the 83 internal reg alternator on

You could probably put the 83 ACV on the 79 manifold (I'm not sure though) to keep from killing your cats.

Felix Wankel

I read somewhere that they were. I didn't see why they would be though.

yayarx7

I agree with all but the last. the ACV will not fit on the 79 manifold.

might as well swap rads while they are out. then the oil lines will reach the cooler. if you go with the taller 83 rad you will have to custom mount the cooler in front of the radiator. I do not know if the lines will reach that far.

I am pretty sure there is an extra T in the heater hose thingy for the oil/water cooler.