I apologize if it looks like I'm not searching, I promise I am. I read about 100 times more posts than I make on here.

First off, I'm a new rotary owner. I bought an '85 GS from work (Texas World Speedway) for $500 with the stock 12A that doesn't run. It'll turn over, but the front rotor doesn't make compression. The rotary-heads next door (Kester Racing, a Star Mazda team) have told me it's not turning over near fast enough, even with a full charge on the battery. Makes me think something's amiss inside. I've tried fogging it with Marvel, etc, but can't seem to make any progress. I've pretty much decided I need to pull out that motor and crack it open if it's ever going to run strong again.

Here's my quandary. I've got a shot at buying a 13B-RE and transmission in unknown condition for $500. It doesn't have a wiring harness or ECU, so it's going to need some parts to get running.

That's the backstory. What's the best way to get this car running? Money is tight, being a college student, but I also want to do this right. The long-term (indefinite) plan is to get a boosted 13B in the car, running relatively reliably. Right now, the two short-term options are A. rebuild the 12A and have something to drive and autocross, or B. swap in the 13B-RE as stock as possible to establish a good platform.

Pros of A are that I'll have something to drive, and have the car drivable while I fix up all the little things that are wrong with it. Cons are that I'm not planning on keeping that motor in there for a long time, as I want to swap to a boosted 13B for more fun. Also a con is that I'd have to spend money rebuilding that motor that's only a temporary resident.

Pros of B are that I'll have a solid platform to build off of in the coming years, and have something relatively quick in the mean time. Cons are that I have no idea what condition the motor is in, and I'm going to have to source a lot of parts to get it working. I'd be making a lot of decisions based on assumptions that the motor is in good condition, although it looks to be in halfway-decent condition at least. Also, everything I read about the Cosmo motor says the existing snails aren't very powerful, and anyone wanting to make power needs to pull them off and install a larger single turbo. That's not in the cards right now, and I'd have to assume the sequential turbos are healthy enough for a little more time.

By and large, this is a learning project for me. I've always worked on more modern EFI, reciprocating cars, and that's the exact reason I picked this one up. I'm up for a challenge, so long as it's not in vain.

 

I believe that the 13B-RE mounts in a different manner than the 12A, 13B, and TII. I think you need a new cross member for it or you lode all benefit of using it instead of the TII.

 

This post leads me to believe it's not that much different:


https://www.rx7club.com/showpost.php...94&postcount=2

But that's the kind of thing I need to know. I've got a massive spreadsheet with all of my options and enumerated costs, projected costs, etc. I'm trying to get a grip on exactly what each direction is going to need before I start buying parts.

 

If it's not a running 13B-RE then you're going to have to rebuild it anyway.

I totally get your dilemma, I was there about a year ago.

I'd say find a running 12a and swap it in... I got mine for $300 and it's lasted me over a year now, still going strong. Plus, it's a straight up swap, so no fabbing is necessary. I had never done a motor swap before, and I did it myself in a day.

I'd also say to buy up that RE and build it. That way, by the time your running 12a expires, you'll have something to drop in and make it a LOT quicker.

 

I like the "running 12A swap" idea, but I can't seem to find a donor anywhere, or just a motor, for that matter. The idea of swapping the motor doesn't intimidate me at all, I think the next time I have time to work on this car I'm going to pull it into the shop and pull the motor, just to clean up the bay, if nothing else. Any advice on removing nonessential emission bullshit would be helpful, I can't find anything solid on what's actually necessary for engine performance and what's just emissions bullshit (I suspect a lot).

I think I am going to buy up the 13B-RE, even if just to go through it with a fine-toothed comb and see exactly what I'm dealing with. May even hook up a starter and try and run a compression test and see what I've got. The only thing I don't like about that course of action is that's $500 I can't spend on anything else (obviously), but that does delay any other action on this project while I save up.

 

the "rats nest" (all the emissions crap) removal is in the FAQ sticky at the top of the page I think about half way down.. ive been meaning to take mine out aswell.

 

Don't forget... In a 12A you need a new exhaust setup before you can rip out the air pump.

 

this is true for re and rew and rx8? anyway didn't most people just swap front plates etc, like they would a TII engine?

 

Find a cheap FC with a running engine. Take what you need and part out the rest. You'll end up getting the parts you need and making a few bucks on top of it. It wouldn't be hard to find a S4 n/a with a decent engine that somebody is willing to let go for really cheap. And FC owners always need parts.

 

Thanks, I'll look into that.

Is that all that's needed to remove the air pump? Just take off the pump, swap the header, and block off the hole in the air cleaner?

I like the sound of that, I might even be able to work that out with my school. I'm the Project Manager for Texas A&M's 2010 Grassroots Challenge team, and we've been thinking about a V8 RX7 for next year's car. I'd have to keep most of the rolling chassis intact, so I couldn't sell a ton of stuff off it, but the idea definitely has potential.

Right now, I think the next step regardless of the final direction is to pull out that 12A and tear it apart. I can't find a running 12A for what it would cost me to rebuild this one for, and if nothing else, it will be good experience working on the internals of a rotary. I mean, ****, it doesn't run anyways. Not like I'm going to mess something up. Maybe I'll find it doesn't need a whole lot of work to go back together and run, who knows.

 

Basically, yes-- HOWEVER! There's assorted vaccum lines and other garbage that comes out as well. I have a PDF of a RR removal that does a pretty good job of explaining the process... I think it's linked from the FAQ (Anyone else notice that most of the links in the FAQ are broken?)

 

If you use a series 2 exhaust manifold, you don't need a header. You will need some sort of exhaust work though.

 

I'm looking into rebuilding the 12A, and when I see the price of a full rebuild kit, all I can think is, "There's got to be a cheaper way."

Am I right in that? I don't care if it's a screamer right now, I just want it to be running so I can move on to fixing the myriad of other issues with this car. Using what little I know about rotaries, I'd like to think I can replace the seals on the front rotor and get the car in running order again, everything else on the car seems to be healthy, relatively speaking.

 

you could take the chance and pull the 12a out and apart, and go from there. either you replace the seal(s) that are bad and put it back together, or more likely you'll find that most of it is garbage

 

With all I'm learning, all signs consistently point to tearing down the 12A and going from there. Either it'll be nothing more than a lesson in rotary mechanics, or I'll find the $300 soft seal and apex spring kit from Atkins will breathe new life into her. I'm not sure I'm willing to spend a whole lot more money than that on engine internals right now. Given all that's happened with the motor, I'm thinking the most likely outcome is the seals are intact, but stuck. Hopefully it just needs a good cleanup and not a new housing, seals, etc.

 

Wow... I went ahead and did a little searching, and there are no 12a's for sale, not even on eBay, in your area.

You could post up a WTB ad in the classifieds section, that's actually how I found mine.

 

I might do that eventually, but I think the next step is to tear the motor apart and have a look inside.

 

I would try soaking the rotor with stuck seal in Seafoam. An ounce in each rotor face. Turn the engine using the nut on the E shaft. A few days of seafoam and turning it should decarbon the seals. Search for Seafoam and decorbon to find more on this.
The slow cranking is most likely battery cables. Check the grounds as well. You might consider replacing the battery cables, both + and - with #2 AWG. Use red for + and black for - ground.

 

HA HA HA

I've got an 83 GSL and an 88 Vert.

I ALWAYS need parts for the FB and NEVER for the Vert. lol