2.8-3.8swap

[88olds]

Hey I have a 88 olds cutlass supreme Int. with a 2.8L with an auto. My trany is shot ( no 1st gear) and now it wont start. So since I love my w-body so much, I'm going to keep the car and do a swap. I want to replace the engine with a 3.8 SC out of a GTP or something and then replace the auto with a 5 speed. I know it will take alot of time and prob. $$$, but its what i want. I want to know what I have to do. If anyone has done this before or knows someone who was, please send me the info i need. A Bonneville SSCI with a 3.8 SC ran 15.2 in the 1/4 mile and My car is a lot lighter than one of them,plue it was done with a 4-speed auto.

[J]

If your gonna get the 3.8sc motor get it out of a park ave ultra or a regal that way it hasn't been beat on, duh a grand prix gets beat on, but park ave's and regal's are older people cars (GENERALLY) and don't get beat on as much. Let us know what u decided to do. Later Jay

[LukeZ34]

Actually.. I'd make sure the L67 was out of a W-Body..
Dave (dykz34 on efi) almost had a L67 out of a late model Buick Rivera, and he later found out, that the mounts were completely different for the motor, and that it wouldn't easily bolt up to a W-Body subframe.

[Intlcutlass]

If you have an intl, you have the upgraded digital dash, and if you go to swap that motor out you will need to put in the computer from the 3800 which does not support your tach.
Other than that you would need to have a custom flywheel made up as the 3800's were never bolted to a stick shift from the factory.
Shawn was working on this for the logest time , and there is another posting somewhere around here reguarding this very topic. He is really the MAN to ask. It can be done, but there are several technical issues to be tackled.
Good luck & let us know what you decide on doing.

[Jeorge]

If you have an intl, you have the upgraded digital dash, and if you go to swap that motor out you will need to put in the computer from the 3800 which does not support your tach.

I have a silly question....what if you used a series II S/C 3800 and a computer from a tornado non Trofeo series I 3800 n/a and the chip from a series I 3800 sc?? I know this may not make sence to some of you
but others will see the link.....??


okay here is my madness

the Tornado NA has a DIGI dash some years with Tach,
the motor is a Series II S/C for the power and the Chip from a Series I S/C because its a s/c Chip?? and not a FLASH ROM like the new ones??

im nuts so dont mind me but WHAT IF??

[Intlcutlass]

Shawn, like I said, is really the man to ask about this. He and I have emailed back-n-forth several times on this subject, and i got so frustrated from my own ignorence that I just gave up hope. But here is what I remember. The Tack for the Internationals gets its signal from a source in the car that would be removed, if one were to do the swap. I don't want to ops: myself by saying anymore than that.
Oh- but the good news is that flywheel....I think I saw somewhere on the Fiero sites, that there is a company that makes that flywheel, as a common updrade to these cars is to throw an L67 manual in them.

[Anonymous]

Try emailing Archie about the flywheel.

http://www.v8archie.com/

[GnatGoSplat]

Yep, I've done much research on this.
It's true, you do NOT want to get the L67 from anything other than a W-body unless you want to make more work for yourself (and nobody wants to do that). It can be done, but you'll be swapping a LOT of brackets and other misc pieces.
The tach in the Cutlass Supreme with digital gauges cluster will NOT work after an L67 swap using the L67's PCM. This is probably the same with the 88-91 Regal digital gauges cluster since I believe it was also made by Nippon Denso. It WILL work fine if you have a 92+ with the analog dash and tach.
Anyway, the Denso cluster gets its tach signal from the ALDL serial data line. The L67 PCM has this (they call it "UART serial data"). Problem is, the tach data is not present in the datastream.

You COULD use a 3800 Series I SC PCM and it will probably have the tach signal... even that's not definite, but I think it does. However, you won't be able to use the 4T65-E tranny and the PCM's calibration isn't ideal for the engine, but it WILL work.

You could also run the original ECM in parallel with the new PCM and just hook up enough wires to get a tach signal into the ECM, and the ECM will put the appropriate tach data onto the serial data line.

Since the original poster wants to use a 5-speed, I think a 3800 Series I SC PCM would be the ideal way to go. Use the 3800 Series I SC PCM, wiring, etc. on the 3800 Series II SC engine. Make sure the PCM is a black sheetmetal formed box that looks like the old one. If it's a cast looking thing and much bigger than the old one, it's an OBD-II PCM which likely won't supply a tach signal on the serial data bus.

[Intlcutlass]

YA SEE!!!
I TOLD YOU HE WAS THE ONE TO ASK!!! :shock:

Good Job Shawn!

[J]

well i done gone lrned some thang new today! I though it'd be better to use a 3.8 s/c out of something else, good thing i found this out cuz i want to do this in the next 2 years or so. sorry just seemed like a good idea! Later Jay