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Motor Swap

Rolling89GPSE

Rolling89GPSE

New member
Been thinking on a motor swap this summer in the 89GPSE i wanna go 3.4 SOHC What vehicle should i be looking to take this out of and what all other parts/wireing adapters etc etc do i need to buy??
 


Well, they'll both have their pros and cons. Up until very recently, the LQ1 was the most powerful n/a V6 GM had. The downfalls are that due to being DOHC, the powerband is way up at the top, they're quite temperamental about maintenance (i.e. must make sure timing belt is changed every 60k) and some of the repairs are a pain (i.e. alternator calls for 4 book hours, though many people can get it done in under an hour). If you get a '91 - '94 motor, you can keep your OBDI comp and wiring, though you're getting the lesser powerful LQ1. If you go '96 & up, you get the most powerful LQ1, but you'll need all the wiring and computer to change over to OBDII.

The 3400 is much more readily available, and would probably be a lot easier to find one with low mileage since they were used on much newer cars. They're not quite as powerful, but being they're pushrod motors, you'll have a much more immediate torque/response. However, you will need EVERYTHING associated with the wiring and computer, as well as the trans since you'll have to convert everything to OBDII. How well these mount up to the Gen I w-body cradle, I can't say for sure, though a 3100 (basically the same motor) WAS used in the last year of the Gen I Cutlass Supreme, so I'd venture to say it shouldn't be a problem, unless they drastically changed something for one year.

Keeping it OBDI would obviously be a lot easier, but switching over to OBDII would give you worlds more options as far as tuning and modding.
 
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I dont even have any interest in using either the LQ1 or 3400 and I found your post RareGMFan to be extremely informative, I think even I could even go out and do the swap now. For that you get a Thanks from me. Good job and thanks for taking the time to be so helpful.
 


RareGMFan said:
I do what I can, especially for the "forgotten generation" of w-bodies. ;)
Click to expand...

Yeah i appreicate the info much, what model vehicle should i be looking to take the motor thats OBDI out of? i would do OBDII but with a kid on the way you can only devote so much time to a car.
 
Any pre-1994 Grand Prix "GTP", Lumina Z34, Lumina Euro 3.4 or Cutlass Supreme that got the LQ1 option. 1994 - 95 got the dreaded OBD1.5, which is a nightmare to deal with, and 1996 & up got the OBDII.
 
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If you're gonna do a quad cam 3.4, watch out for the timing belts, My '96 Monte Z34 was a pain in the @$$ do change the belts. And when i brought it to the local garage, the Mechanic said to me " You didn't tell me it was THAT engine" and he looked alittle nervous about it; and the GP's from those years have No room under the hood, I've compared my '90 LE coupe with my Z34, and there definitely is a difference. I'm planning on eventually a 3.4 swap with a 5 speed on my Grand Prix, and If you have good welding skills, you can make dogbones that are stronger and will fit, thats the route I'm taking
 


id say if you wanna stay obs1 try finding info on the series1 l67 still makes 205hp stock and shouldnt be to hard to change would def be more reluable then the lq1
 
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