I have posted several seperate post involving my 13B N/A swap into my 1985 GS. I have decided to consolodate them into one ongoing post untill I finish my project. So I am going to stat from the begining.

The car started life as a 12A powered base model, I bought off ebay with a parts car for $143 about 1 year ago. The car was fairly straight but after further inspection the rear rotor had shed an apex seal. I let it sit untill one day a buddy bought a wrecked FC and I couldn't resist. I decided contrary to popular vote to keep the car EFI (more on that later)

I gathered all the parts needed for the install, the parts car (87 se) had the motor, ecu, EFI, wiring harness, coils, ect.

I bought the GSL-SE oil pan, and modified the motor mounts (as pictured) that were on the 12A originaly. I had to use the 12A oil pickup and I also used the 12A front cover (to hold the motor mounts). *note* you also have to use the 12A OMP if you are going to use the front cover from a 12A....

For this application I am using a 12A transmission so no fabbing will be needed to get the tranny to bolt into place (as a 2nd gen 13b requires custom mounts) I also retained the 12A driveshaft.

I will discuss the wiring in another post in this thread later.. Anyways here are the pictures of the motor mount modification, the motor in the parts car and then the motor in my 7.. To pull the motor and simplify everything I pulled the wiring harness through the firewall, and unbolted all the sensors and layed them on the block eliminating any confusion.. Stay tuned progess updates will follow.

 

I like this thread. I'm doing a similar conversion. 13B from an 89-91 non turbo into an 85 GS. I bought the front motor mount plate from MaxdaTrix. A lot cheaper to modify a 12A mount, but since this is my first I didn't know what is required. Also, I'm going with a Racing Beat Holley carb and intake, just to make it simpler. I have my motor pieces (rotors, stationary gears, e-shaft) at the machine shop now, and hope to start rebuilding in the next 2 weeks or so.

Keep posting pics...I will also if there is interest.

Rich

 

Won't the computer throw a code because your not using the electric omp?

 

My OMP is mechanical, as is the 13B one... The 89-91 Rx-7's had the electric OMP's if I am not mistaken...

 

I was told that you had to hang a 13B OMP off the side of the motor to keep the ECU happy if you are sticking with the EFI.

 

Yea, that's correct...my response would only pertain to the 89-91 13B...

 

Gotcha

 

This will be good, everyone ask any questions you want, they can all get answered in one thread and this will be like a growing 13B install "bible" for those doing the swap..

1st question answered 86-88 N/A 13B's have a mechanical omp...BUT if you are using a 12A front cover you must use a 12A omp.. 89-91's have an electric OMP, so you will have to rig it so you don't show an error code.

NEXT!

 

this maybe a dumb question but what is a omp?

 

Oil Metering Pump. Provides oil to engine internals. Injected into fuel-air mixture. SEARCH!

 

sorry

 

NP, your here to learn. There are a lot of questions that have been asked, so sometimes you can find stuff you need by just searching so you are encouraged to try that first. Glad to help though.

 

Not sure the 12a OMP will work, it only has two output lines where as the 13b OMPs have four. I think the GSL-SE OMP can be made to work with the S4/S5 setup, but then you need the SE front cover.

Premix is always an option also.

Scott

p.s. Isn't there another thread like this somewhere??? jk

 

Take the RA OMP adapter (for electronic OMP) , and have the inner face remachined to match the 12a cover, or make a new adapter from scratch that matches between the two. any machine shop could fab this up, it might cost you a hundredor so, but ya want to play ya gotta pay.

kenn

 

nah, just go easy: splice the lines from a 12A OMP. I did it that way, it's really easy. The 13B engine doesn't need more oil or something, it just uses 4 lines instead of two. So splicing the 12A lines is ok. Or indeed, go with a GSL-SE front cover.
Something about that transmission though: an FC NA tranny is no different then the one on your 12A. All what's different is the mounting bracket. So what you can do is take the brackets (the silent block too) from one to the other, and there you go. 12A shaft will still work. A TII box is the one that'll need fabbing.

 

I understand the Non-turbo Tranny will work, but my main reason for using the 12A is for the hair difference in acceleration, the gearing on the 12A tranny is set up a little better for autocrossing.

As for the OMP I am going to use y connectors and just splice the two hoses into one, I will also be premixing MMo as I always premix aswell as a precaution anyways.

 

What are you doing for Fuel?

The GS 12a originally came with a carb, and IIRC the pump for the S4 is in-tank. Have you decided what fuel setup you're using.

And I know you said you'd talk about wiring later, but what's the gist of what you had to do to get it hooked up?

Did you manage to salvage the rad out of that wreck, or are you using the 12a rad? In either case, what did you have to do to mod it up (mod the S4 rad to fit the 85's mounts, or mod the tubes to fit the 12a rad to the engine)?

More questions as I think of them
Jon

 

Great questions....

For starters I am on the fence right now about the fuel pump, I am building this car on a budget and am trying to take the "Cheapest" route I can to prove you don't have to have a lot of money tied up in a competitive track car or daily driver... So far the total is as follows.

$143 purchase price (2 cars)
$60 gas to pick both up
$55 Oil Pan
$179 for clutch (not needed but wanted fresh other one was fine)
$300 for wrecked FC with motor
$120 for tune-up items

Durring the strip down process I sold lots of Rx-7 parts on the forum, to many of you probably.. totaling around $500.

So currently I have
$857 in total purchases
-$500 in parts for the cars
= $357 in the car right now

It still needs paint, springs and a set of 14" rims to fit the race tires my dad donated, firegslse and I are working out a deal on some adjustables and it'll be done.

For well under $1000 I will have a 13B powered 12A car.

I am thinking of a masters univeral 45psi fuel pump from autozone (not currently avail but the website has a listing) meant for external inline usage. If not that I will probably go holley or something similar.

I am also going to attemp something different then I have seen so far as far as the wiring goes. Most people cut and splice the wiring to work... I am going to attempt to retain Both the FC wiring harnesses, instead of cutting and splicing ECU pinouts I will rewire the lights ECT, on my car instead, by doing this I am hoping to eliminate the problems that occur from messing with the ecu wiring. I am planning on using the idiot cluster and lots of the other parts that some people eliminate when sawpping.

I am retaining the 3 core rad that came in my car along with the front mount oil cooler. It is actually a superior rad. I had a spare FC rad but really like the 12A 3 core. I will be using an electric fan and pushing the rad forward a few inches.

Thanks for the question and keep them comming.

 

I used a Bosch fuel pump from a Porsche 944, seems to work fine.

 

i'm going to be doing a swap like this soon (S4 13b into GSL-SE). assuming i'm just going to premix, is there a OMP blockoff i'll need and if so, can anyone let me know where to get it? what about blocking off the lines and fittings for it?

 

Lots of people on the forum have sold them, I made one for my holley setup, it is pretty easy...

Why would you block it off when your gsl-se OMP will work just fine? Premixing is fine I do it but the extra protection of the OMP is a nice insurance policy. Consider keeping it if at all possible..

 

did you get new gaskets for the front cover/ oil pan or did you make your own?

i'd love to do this swap... just can't seem to find a motor for the SE....

 

I used Ultra blue- it works great, I have never had problems in the past... The ultra black looks better (finished product) but the ultra blue is a little tackier ( in the good sticky way)

I broke down and bought a sandblaster today....... Check out my first peice. It's my thermostat housing.. what do you think.. I am using the 12A housing instead.. It will simplify the radiator install. Sandblasted with MGO then wire brushed then Clear coated 5 times with high temp clear....

 

Sandblasting is great isn't it? The only problem I have with it is the mess. I built a blasting box and it doesn't seal very well, so I have to sandblast outside to avoid the mess.

 

Fuel has been decided! I am in the market for a gsl-se fuel pump, it should flow pleanty for a stock setup. I can get a new one with a lifetime warrantee for $92.00 from autozone, so if anyone has one for sale cheaper let me know.