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3.1L to 3.4 DOHC swap


KinG_NothiN

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i got a question about an engine swap. I have a 3.1L in my 90 Lumina Euro and was maybe thinking of upgrading it to a 3.4DOHC. i know they didnt make a 3.4 in 1990 for the Lumina, so i was wondering if it would still be possible (without a lots and lots of extra work) to swap one from a later model z34 or another w-body? any info is greatly appreciated, especially info on whats involved in parts that have to be converted

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instead of just doing engine, trans, and wiring harness(among all the tiny stuff you need like every heater hose, ac line, alternator duct, etc...), you need to swap the engine cradle. easier anyway as you just unbolt everything and jack the body off the drivetrain/cradle assembly. had mine done in 2 days.

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well, this is new to me, so u have to explain in more detail. how is the engine cradle different from doing what i was talking about???

also, as i mentioned before, is this going to be a little more tricky because the 3.4 was not available that year for my particular car??

u had an advantage as the z34 had already been around for several years for your swap

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the cradle(aka front subframe) for 91-up has the front mount pad welded on for the 3.4.

 

basically, i undid the wiring from the body and laid it over onto the engine, pulled the axles and all the shifter and throttle cables, undid all the hoses and removed the radiator and fans, undid the steering column from the rack and the tie rods from the spindles, popped the lower ball joints loose, unbolted the cradle(with it sitting on the legs of my engine hoist), and used my engine hoist to lift the body of the car up and off the cradle. put jackstands under the 2 formed rails in the floor , and wheeled out the old drivetrain. then i plopped the new drivetrain onto the engine hoist's legs, rolled it back under the car, chained the hoist back to the core support, removed the jackstands, and lowered the body back down, and reversed everything.

 

you wont have any worries because a 90 lumina is the same as a 91-94

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pat, if you would like to do a write up for this, I can host it on the 60V6 site. I have seen this topic quite a few times and you always type everything out:)

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awesome, i didnt realize it could that easily. i really appreciate the info. u make it sound so easy. :D

i think it would be great if you do a write up on it thought, like u guys were are about. the more detail the better, that way i have somewhat of a manual to go by too so i cant screw up when the time comes to do it

i think i'm gonna start keepin my eyes out for a doner car this summer since i seem to be at the wreckers so often. trick will be finding one with low clicks on it

btw, one last question on the subject electrical wise (since u've convered everything mechanical). will any modifications have to be done to any wiring harnesses, and the ECM and what not should be okay to just transfer over as well?

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the whole engine/powertrain harness comes out with the engine. there is one connector at the firewall behind the pass. side of the motor that gets unscrewed. the ECM and whatnot, fuse blocks, relay center, etc... all come out with the motor and get swapped right into your car. no wiring is necessary. i'd try and stick with a 91-92 donor car to keep the fuse blocks the same. i kept my 3.1 harness, because my car is a 94 and the donor was a 91, i wanted to keep the 94 style fuse and relay blocks for a factory installed look.

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