Thoroughscrub

I'm curious if anyone knows how much I should expect to pay to swap my 12a for a 13b.
Pick A Part has a 13b for sale and I'm curious, would swapping the 12a out of my 84gs for the 13b, be much more expensive than replacing the apex seals - as It's likely I may need to do that.

If anyone has rough estimates - say a shop charges $70-100 an hour, as I don't fancy myself able to do the swap.

FunK73

iTrader: (6)

You could do the swap honestly. The cost is very dependent upon what you have and what you're going to do.

PercentSevenC

Yes, it's a very easy swap as engine swaps go, but since there's no intake manifold that will let you use your Nikki carburetor on a 13B (without modification, anyway), you're looking at either a carb swap or EFI conversion at the very least. Also, the exhaust will need to be modified slightly to accommodate the extra length of the 13B, which requires a welder or shop time (or just buying a Racing Beat exhaust system designed for this application). There are some other little things that need modification as well, but nothing major.

None of this is particularly difficult, and there's plenty of information on this site to help you through the process, but if you're the type of person who doesn't want to get his hands dirty and spend some time reading and learning, it may not be for you.

But yeah, the cost of shop time is going to depend on a variety of factors. What are your goals for the car? Which 13B is it? Will it be carbed or fuel injected? If carbed, which carb, and who is going to tune it? What else are you going to upgrade/replace at the same time? Does it have to pass emissions?

Thoroughscrub

I guess it's possible.. I kind of have access to a friend's shop too...
Lets say I just buy a 13b, What kind of other things Could I need?
Supposedly an 85 13b should bolt on no problem. Will I need a bigger carb, or am I correct in remembering the 13bs are injected?

Thoroughscrub

Being in Oregon, no, I don't have to pass any emissions.
There's a brand new exhaust on it, so I'd just have that shortened for the 13b.

If it's not obvious I'm starting with pretty much no knowledge. I'd like to not spend several hundred more on a new carb, but.. honestly I just don't know what's best. I don't need to buy the best of the best, for sure. I want to keep it somewhat modest, I just figured if I have to get the engine pulled and taken apart, it might just be easier to swap it out and not bother with a rebuild.
I don't mind getting dirty at all! Reading and learning doesn't bother me either. It's just that I'm stating with very little direction. So specific directions and estimates are greatly appreciated.

PercentSevenC

An '84-85 (GSL-SE) 13B won't quite drop in, but close. You need to account for the front of the engine moving forward by 20mm. There are several options: buy a Racing Beat front engine mount bar, find a GSL-SE crossmember, or modify your 12A stuff by slotting the holes. The exhaust will have to be lengthened slightly. The fan shroud has to be modified as well if you want to use the stock clutch fan. Oh, and since it looks like you have an '84, you have to deal with the oil cooler, too. It's a good idea to convert to a front-mounted air oil cooler, but if you have to, the "beehive" water oil cooler can be modified to work with a 13B.

Then you have to deal with fueling. If it's a GSL-SE engine, it's fuel injected from the factory. You have two options: keep the EFI setup, or go carbed.

If you want to go with a carb, as I mentioned there's no easy way to just use your stock 12A carburetor. You'll have to figure out which carb you want to use and get a suitable intake manifold for it. Weber (sidedraft or downdraft) 2-barrels or Holley 4-barrels are the typical choices. There are lots of Weber and Holley threads here that will help you learn how to tune your new carb, and if you buy a kit from Racing Beat it should already be tuned pretty well. You could also probably use a Holley style intake manifold and make an adapter plate for your Nikki carb, but it's possible you might run into hood clearance issues, and the stock carb doesn't flow all that well anyway. None of the aftermarket carbs will drive as nicely as the stock Nikki, though. Debating the relative merits of various carb options is a topic that has been beaten to death countless times already, so I won't bother going into it here. You'll need a fuel pump and pressure regulator to match whatever carb you end up using.

To go EFI, you'll need at minimum a suitable high-pressure fuel pump, a larger fuel return line, new EFI-rated soft fuel lines, and the complete ECU and wiring harness from the GSL-SE. I know there are writeups here that detail how to swap in a fuel-injected 13B (they might be specifically written for second-gen engines, but the process is similar either way). It's more work, but IMO it'd be worth it.

mazdaverx713b

iTrader: (91)

i have swapped an entire EGI 13B from an SE into a 12A car with near flawless results. i have a list of parts you need and can guide you down this road should you choose to go down it. if you do let me know and i will provide all necessary info. if you want to read my build thread and allow it to give you some insight on what's all involved in the swap here's the thread:

https://www.rx7club.com/build-threads-293/85-l6-gs-se-project-restoration-822222/

Thoroughscrub

Hmmm... It sounds like a lot of little mods that I won't be able to do on my own..
I went to the Mazda dealership today to get some more info on vacuum tubes - no help there. And the guy said that the late 84 through 85 13b "should" bolt up no problem. It sounds like you guys know what you're talking about a bit more though, so I'm inclined to listen to you.

So ultimately. Still curious abouthow much I should expect to throw at it. Say I take the simplest options, keeping as much unmodded as possible.

Sounds like it would be cheaper to get a carbed 13b.. rather than go EFI. That true?

Thoroughscrub

I see that "EGI" wasn't a typo for "EFI" now...
Is it the same thing? Electronic Gasoline Injection?

PercentSevenC

It means the same thing. "EGI" was the terminology Mazda used back in the day.

I can't really give you an idea of how much the labor is going to cost, as I don't take my cars to shops. But the parts cost just to get the engine in the car can be pretty minimal if you know what you're doing, especially if the engine already has a GSL-SE oil pan. You can modify your 12A engine mounts, fan shroud, and beehive oil cooler for free. Having a shop modify the exhaust should be cheap enough.

The rest of the parts cost is in the fuel delivery. If, for example, you buy the Racing Beat Holley kit brand new, it's about a grand, plus the cost of a fuel pump and FPR. But you can often find used stuff on the forum for quite a lot less than that. If you can find a complete long block with a good wiring harness and ECU, a fuel injection setup could end up being cheaper, but more complicated to get working. In the end, the EFI setup would be a lot more pleasant to live with, though.

By far the easiest option would be to get a pre-'84 13B with a stock Hitachi carb. All you'd need is a fuel pump, pressure regulator, and a GSL-SE oil pan. But finding one of those old-school engines in good condition might be tough nowadays.

Thoroughscrub

Hmmm.... It doesn't sound like I'll be able to get anything done for less than a grand...
I'd really like to not be into this car for $2000... Just to have it running.

So much of the terminology just goes right over my head, having trouble knowing what to look for and where...

About how long do you think it would take a shop to do these given things?

PercentSevenC

It's going to be really dependent on the shop, I think, and how much experience they have dealing with the FB chassis. Unfortunately, all the rotary shops I know of in Oregon are in the Portland region, but ask in the NW section and someone might be able to recommend a shop. Then just try calling them. Or, there might be a forum member in your area who's willing to lend a hand.

Working by yourself in your driveway, it's easily a weekend job. You could probably do it in a day if you knew what you're doing and had all the tools and parts you need on hand.

Rotospeed

iTrader: (8)

or... start looking for a used 12a you can find them from $300- $500 + shipping.

just giving you idaes befor you start into it.

Thoroughscrub

I do appreciate ANY advise!
I'm thinking it may be best to stick with a 12a.
Anyone know if it's easier/cheaper to install new apex seals or just go with a whole new motor?

PercentSevenC

Probably cheaper to get a used motor. But that means you're (obviously) getting a used, most likely high-mileage, motor. Just depends on your situation and what you want from the car.

Thoroughscrub

My 12a has 140k on it...
More performance would be cool. So I'm not necessarily looking for the cheapest option. But simpler would be better.

Can someone tell me, and I apologize for the quality of the picture, it was really the best I could do...
I dooon't think the rear float bowl looks right, but I can't tell for sure..

http://img232.imageshack.us/img232/7690/float3.jpg
http://img857.imageshack.us/img857/5549/float2.jpg
http://imageshack.us/photo/my-images/695/floatk.jpg/

Rotary-MG

iTrader: (1)

I was able to get my donor '84 SE for $600.
all it needed was a new TPS and it was running like a champ.
Then I pulled out everything and sold the empty shell for $200.
I'm sure that I could make a profit if I just sold a few more items.
There's a bunch of stuff that I kept that I'm not using, like the tranny, rearend, gauges, etc...

You can get your 13B or 12A for free if u have time and can be clever enough.

Thoroughscrub

What do you mean free??

Rotospeed

iTrader: (8)

Buy a cheap car sell half the parts to make your money back...profit engine

cshaw07

iTrader: (14)

^ exactly, in one deal i did. i got a spare engine and tranny, a full interior, made my money back and had enough left over to buy another car thats running, driving, and in awesome condition. You can do it. look on CL

Rotary-MG

iTrader: (1)

bravo!

bugman1973

the thing that really sucks about the swap is that you need to either replace the entire front wiring loom or figure out a way to make it work with the stock 12a set with i wouldnt suggest i fought that car for months i finally broke down and got the gslse wiring harness and ecu. what really sucks it that the ecu controlles the headlights turn signals i think all in all i spent about 500-1000 when all was done which is not that bad at all