Will an '83 12A work in a '79?

Zero5360 · 05-12-2011, 07:35 PM

I'm trying to restore a 1979 Limited. However, the engine is giving me nothing but problems. I have an '83 parts car with a motor that run wonderfully. Will the motor from the '83 drop into my '79? I know they have different carbs and alternators, but I didn't know if they were interchangeable. Thanks!

djmtsu · 05-13-2011, 06:49 AM

The block is essentially the same. Swap over all your external manifolds/alternator and such and hammer down!

730RWHP12A · 06-25-2011, 10:09 PM

its not a direct swap, but with some mods it will work. mainly the thermo reactor wont bolt up to the later 12a motors due to the egr config.

sgt.stinkfist · 07-03-2011, 01:51 AM

was it only cali that got the egr's on the 12a? i dont recall there being any EGR's any of my 12A's. i have "federal emissions" versions of each series; S1, S2, and S3, and there is just a blank non machined spot where there EGR's are on the center iron of later motors. i think there is a difference in the relation/covering of the air injection port and intake manifold between the series on the side of the center iron, but if your running a header then it shouldnt matter. overall tho, it should be a pretty strait forward swap.

13x · 07-26-2011, 11:59 PM

just use the intake and exhaust from the 83 and away you go, ask me how I know

05-12-2011, 07:35 PM	#1
Zero5360 The Newbie Join Date: May 2011 iTrader: (0) Posts: 3 Rep Power: 0	Will an '83 12A work in a '79? I'm trying to restore a 1979 Limited. However, the engine is giving me nothing but problems. I have an '83 parts car with a motor that run wonderfully. Will the motor from the '83 drop into my '79? I know they have different carbs and alternators, but I didn't know if they were interchangeable. Thanks!

05-13-2011, 06:49 AM	#2
djmtsu My minds tellin' me no... Join Date: Feb 2008 Location: Murfreesboro, TN iTrader: (10) Posts: 4,043 Rep Power: 21	The block is essentially the same. Swap over all your external manifolds/alternator and such and hammer down! __________________ 1976 Mazda Cosmo RX-5 1976 Mazda Cosmo RX-5 2003 Toyota Tundra TRD 2015 Toyota 4Runner SR5

06-25-2011, 10:09 PM	#3
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california iTrader: (8) Posts: 349 Rep Power: 17	its not a direct swap, but with some mods it will work. mainly the thermo reactor wont bolt up to the later 12a motors due to the egr config. __________________ rotaryshack.com

07-03-2011, 01:51 AM	#4
sgt.stinkfist The Newbie Join Date: Jun 2011 iTrader: (0) Posts: 16 Rep Power: 0	was it only cali that got the egr's on the 12a? i dont recall there being any EGR's any of my 12A's. i have "federal emissions" versions of each series; S1, S2, and S3, and there is just a blank non machined spot where there EGR's are on the center iron of later motors. i think there is a difference in the relation/covering of the air injection port and intake manifold between the series on the side of the center iron, but if your running a header then it shouldnt matter. overall tho, it should be a pretty strait forward swap. __________________ 82 GS- GSL rearend, ported S4 13b, MSD 6AL, walbro 255, 460/550cc injectors, 2" dual exhaust, 3 row aluminum radiator w/ taurus E-fan 85 20v ST AE86 - sold to fund the 82 86 RX-7 GXL - donating parts to the 82 everything else - scrapped to fund the 82 Last edited by sgt.stinkfist; 07-03-2011 at 01:56 AM..

07-26-2011, 11:59 PM	#5
13x SinCityRotary Join Date: Feb 2010 Location: Sin City iTrader: (0) Posts: 207 Rep Power: 15	just use the intake and exhaust from the 83 and away you go, ask me how I know __________________ WHiV8 in the works!! May 2015 Email