Performance engine swap, and introduction.

[BodyTechGP]

Hi, I'm new to this board and have a few questions. First I'll introduce myself. I'm an AutoBody Technition, not a mechanic. but I have a decent understanding of mechanics. engineswaps are no big deal for me when replacing with same type of motor,quite comon opperation in a bodyshop.

 

ok, here's my question. I have a 1990 GP with the 3.1 Multi Port in great running condition. I also have a 1994 Lumina Z34 with a bad trans, and a facelift (the kind where you have to call the insurance company ) . I loved the power my Z34 had and am wondering what I'd be getting myself into by swapping the 3.4 into the GP. can I use my trans off my GP on the 3.4? what are the problems with the engine swap? wiring, exhaust, etc? also, if I put the 3.4 into my GP, what are some of the upgrades I can make to to the 3.4 for even better performance?

 

Thanks,

Matt

[Guest RedCutlassSL]

it should be a relatively easy and direct swap. plug and play in computer terms. The tranny will work. You are gonna need the ECM from the z34 however.

[Robby1870]

I think the engine cradle that the 3.4 used was different than that for the 3.1L (some one correct me if Im wrong). Your trans with the 3.1L would bolt up, but its not going to last. If doing motor swaps is easy, find a manual (91-93) that came with a 3.4 and do that whole swap. OR, get an auto from a turbo grand prix (89-90), its the same trans as the one with the 3.1L, the 4T60, but beefed up via, valve body, torque converter, etc, to handle the extra power from the turbo 3.1L. Theres not much performance stuff out there for the 3.4, other than the basics, exhaust, intake. Welcome to the board, hope you enjoy it!

 

Robby

[Vegeta]

The 90 subframe doesnt have the mount location for the DOHC, so if you can salvage teh subframe off teh Z34, you are in luck. The computer swap might not be necessary if you are using a 4T60 vs a 4T60E. You would be better off using a 4T60-E so that the computer will be ultra simple (other than adding a few wires to it on teh 90). With the 4T60, I have no idea when it will want to shift for you. The FDR is slightly lower but the real issue is shift points, which you cannot control on a 4T60.

[Robby1870]

yeah and with that LQ1 revving to 7K, that 4T60 is not going to know what to do, when it comes to shifting. Plus, the 4T60E was originally mated to LQ1 anyway. But, I would find a manual tranny if I was him

 

Robby

[BodyTechGP]

Thanks for the replys, I have the complete Z34, so the cradle is not a problem. sounds like my only real concern is the trans. The trans in the Z34 has a hole in it the size of my fist ( I never drove the car easy ) . ok, so far I gather I need to replace the trans, but the cradle and computer etc. is a direct bolt in.

 

Since I'm going to have the motor out anyways I'm planning on replacing the cams, timing belt, having the heads reworked, and maybe a little work to the intake (port, polish). any sugestions on cams? also exhaust, I was thinking Flowmaster but want to make sure not to have a "rice burner" sound.

 

Thanks a million,

Matt

[Robby1870]

Personally, I have heard that flows dont sound good on these cars. Magnaflow sounds pretty good. Are you going for performance cams? And while your at it, shave like 30 or 40 thousandths (if possible) of the heads, and get some extra compression. Comp Cams and Crane Cams too will custom grind cams for you. They have a worksheet on their site, you fill out about them. Comp Cams is a good place, they know their stuff. Im gettin performance rocker arms from them. I have sent many emails and they resond quickly and answer all questions. Port and Polish on the heads is a good idea. Might as well, port and polish the intake manifolds too. Theres a bigger Throttle Body out there somewhere, like 72mm I think, if your interested.

 

Robby

[Vegeta]

There are no cams, you cant get a regrind from comp, crane, or lunati. You shouldnt shave 30-40 thousands off your head unless you want it to me an interference motor. You can change the cam timing which helps, and doing head work REALLY helps. I did a set of heads for a friends DOHC and it really gave it a nice kick in the ass. Intakes, extrude hone for the plenum if you want but its expensive. The lower is pretty easy to do with a die grinder. The TB max is 69mm.

[Jasonz34]

Transmission will be your biggest problem. If you can swap in the getrag 5speed you'd be in awesome shape, but good luck finding one. They're hard to come buy and even more fun to swap unless you have a doner car. Your best bet is to find another 4t60e and get it rebuilt. If you don't mind spending money go ASG. http://mywebpages.comcast.net/autoservicegroup1/

[Robby1870]

yeah now that I think about it, 30-40 thousandths is WAY too much, just port and polish. And that sux about the cams. Thanks Vegeta for the info, and I wasnt sure on that TB diameter

 

Robby

[patgizz]

you may want to check out the 3.4 DOHC section of the 60 degree v6 forums on gmforums.com

 

i went thru this(put a 3.4 into my 94 lumina that had a 3.1) and i documented every part that needs to be swapped over with the engine. i think its in the general section

[GnatGoSplat]

I'm just guessing, but I don't think you HAVE to swap the trans.

The shift points won't be computer controlled, but it'll still shift regardless. If the shift points are close within a certain range, the ECM might not complain. Granted, swapping the trans would make things a lot more straight-forward especially where wiring is concerned. I don't think the 4T60-E is all that much stronger than the 4T60.

 

Your '90 MIGHT have the proper mounts on the subframe for the 3.4. The only way to know is to take a look. Compare the right (passenger side) where the 3.4 mounts to the subframe and see if those places are on your '90 subframe. Later model 90's got the correct mounts because late 90 was the first year of the 3800 Series I in the Regal, and that engine uses the same mounts as the 3.4 DOHC.