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Swapping 12a to 13b

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Old 07-21-16, 05:38 PM
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Swapping 12a to 13b

Any tips for swapping a 12a chassis to 13b? Fuel lines, fuel pump, starter motor, cooling system, oil cooler all bolt up?


My car:
https://www.youtube.com/watch?v=n09KC1woxNs
Old 07-21-16, 05:46 PM
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Yes. Search.

There are literally dozens of thread on this exact subject.

Start here.

https://www.rx7club.com/1st-generati...q-page-237777/
Old 07-21-16, 08:32 PM
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EFI is overrated.
Old 07-21-16, 08:35 PM
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All of it bolts right up. Just make an adapter plate for your carb, lengthen your motor mounts, and spread your exhaust a little wider.

Wait... I just watched the video link. Your plan is to pull a 13b and then get it rebuilt? Why not just rebuild the 12a?

Last edited by Qingdao; 07-21-16 at 08:42 PM.
Old 07-22-16, 10:13 AM
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Originally Posted by Qingdao
All of it bolts right up. Just make an adapter plate for your carb, lengthen your motor mounts, and spread your exhaust a little wider.

Wait... I just watched the video link. Your plan is to pull a 13b and then get it rebuilt? Why not just rebuild the 12a?

Because the 12a that in it now has been rebuilt before, and I worry the block has just had it at 170k miles. Plus I wanted a little more power anyway, and fuel injection for cold starts since I'm in chicago, so a 13b just seems like the smartest route.
Old 07-22-16, 05:16 PM
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^ I'd try a larger port before moving to 13B unless your irons and housings are just trashed and you can't find any.

Not trying to talk you out of it, but that's the route I'd go. In fact I've been tinkering with the idea of rebuilding my other car's 12A and running it.

Just seems like the less complicated way of going about it. You've got a 12A with all the things you need to make it run as is (ie carb, exhaust, motor mounts). If you pull your engine and rebuild it with a larger port you'll gain a bunch of power and all you'll have to change is your carburetor. Like you mentioned in the video you are starting school and shouldn't have to deal with a whole bunch of complications like finding manifolds for a 13B or (god help you) finding FI equipment.



EDIT: oh wait you WANT fuel injection.... damn you're just a glutton for punishment.
Old 07-24-16, 12:14 PM
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Originally Posted by Jeff20B
EFI is overrated.
didn't say anything about EFI..


plus EFI is awesome

however the easy peazy swap is a carbed 13b and do what every other ****** did and slot the motor mounts (or get an SE crossmember) you'll also need the SE oil pan to fit the cross member ... the intake and exhaust manifolds to fit the 13b and you're pretty much done.
Old 07-25-16, 10:44 AM
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I have done this, if using EFI you will need to...

-use a surge tank (internal or external, I used internal from Coachman Performance) or stock GSL-SE tank will work on a s3 12A chasis
-upgrade the return line from teeny tiny to 5/16"
-GSL-SE fuel pump, new from Atkins
-GSL-SE wiring and computer are the easiest for s3 chasis
-notch the front mount bracket into L shapes, or get the RB conversion bracket
-12A starter works fine on a 13B
-12A trans works fine on a 13B
-Custom exhaust (or RB Road Race for GSL-SE)
-12A or GSL-SE dizzy



If your going carby...
-notch the front bracket
-Custom exhaust or RB Road Race system for GSL-SE
-upgrade fuel pump for carb requirements
-12A or GSL-SE dizzy (technically GSL-SE are different, but not needed.) one is larger
-12a mounts work (technicially GSK

Last edited by NCross; 07-25-16 at 10:47 AM.
Old 07-25-16, 12:07 PM
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Old 07-26-16, 02:34 PM
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Originally Posted by NCross
I have done this, if using EFI you will need to...

-use a surge tank (internal or external, I used internal from Coachman Performance) or stock GSL-SE tank will work on a s3 12A chasis
-upgrade the return line from teeny tiny to 5/16"
-GSL-SE fuel pump, new from Atkins
-GSL-SE wiring and computer are the easiest for s3 chasis
-notch the front mount bracket into L shapes, or get the RB conversion bracket
-12A starter works fine on a 13B
-12A trans works fine on a 13B
-Custom exhaust (or RB Road Race for GSL-SE)
-12A or GSL-SE dizzy



If your going carby...
-notch the front bracket
-Custom exhaust or RB Road Race system for GSL-SE
-upgrade fuel pump for carb requirements
-12A or GSL-SE dizzy (technically GSL-SE are different, but not needed.) one is larger
-12a mounts work (technicially GSK
Will the oil cooler/radiator bolt up?
Old 07-26-16, 06:38 PM
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Originally Posted by lambothirteen
Will the oil cooler/radiator bolt up?
All the 1st gen body's are relatively similar. You'll be able to bolt on any oil cooler and radiator setup you find. If not its as simple as making a mount.
Old 07-27-16, 11:59 AM
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Do you have the oil pedestal cooler??? probably not, but you should be swapping that crappy thing out any how.

otherwise everything will work.

as far as the fuel system, it should be ok for a stock 13b and can always be upgraded at a later date.
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