View Full Version : 3.8 turbo on a 4.1????

02-10-2005, 09:50 PM
I have a 4.1 engine
and have access to a 3.8 turbo engine that is destroyed
block and crank destroyed but
the turbo is good.

what I am asking is will the 3.8 intake and turbo unit bolt up to the 4.1
if so what all will I need from the donor engine and vehicle?
what mods will I need to make to the 4.1 block if any?

the donor is an 84 hot air
can you even do this swap?
what all will I need if you can?
the complete engine wiring harness all the way to the computer?
the computer itself
intake and breather set up
all the plumbing
can even get the cat if needed
is this a doable swap?

just looking for more power in a daily driver
not a street strip competition thing

I have the 4.1
and possibly access to a 3.8 turbo with broken internals from an over rev
the block and crank are destroyed as well as most of the other parts
the intake and turbo are in good condition.

03-09-2005, 11:23 AM
Since the 4.1 was an older carbureted system, and the 3.8 Turbo injected with much more in the way of electronic controls, I'd think this would be difficult.

That is, can cam and/or crank sensors even be installed at all on an engine that was never equipped with them in the first place? I don't know, but I would think this might be a limiting factor with using the FI system at all.

03-09-2005, 11:46 AM
The biggest concern would be the pistons in the 4.1 (too much compression? Strong enough for boost?).

Physically, everything should fit (since the 4.1 is basically externally identical) as far as block/heads/etc. You'll need all the accessory brackets, electronics, wiring harness, manifolds, etc. from the 3.8.

However, the internal issue would be with the 4.1's pistons.

03-09-2005, 01:55 PM
I can't say anything with regards to piston strength, but as far as I know, the 3.8s and 4.1s all ran only 8.0:1 compression . . . at least, until the C-code 3.8 was released.

04-02-2005, 01:32 PM
I know a little about this as i was giong to do the same thing! You need a Fuel Inj. CAM. Carb cams have differnt grind and won't work.The crank out of the 4.1 is the same as 3.8 so it will work.Oil return of some type From turbo to the block,usually adapt 3/8 or1/2 steel braided line to timing cover.But the reason I didn't do this is lower end of 4.1 is NOT as strong as 3.8 Block so most people Girdle them! Hope this helps! :) :) :)

05-12-2005, 05:17 PM
How do you get all the sensors and such to work when using a 4.1 if you're going for the GN-type of FI/Turbo system?

05-12-2005, 05:19 PM
There's no physical difference ... all the upper end of the motor is the same. Same intake, same heads, same ignition/fuel systems.....

05-15-2005, 08:37 PM
How do you get all the sensors and such to work when using a 4.1 if you're going for the GN-type of FI/Turbo system?
its basically the same as looking at a 305 and 350, they look the same on the outside. timming covers, oil pan, valve covers etc.. all interchange

05-16-2005, 08:00 PM
Hmm, didn't realize it could be that simple.

So, hypothetically speaking, if one had a typical 2-bbl 3.8L V6 in a regular old granny-type Regal, could it be adapted to FI (non-turbo) by swapping the parts on from a FWD Delta 88 or something like that from the late 80s?

The reason I ask is because I'd always assumed that the block had to be provisioned from the factory for the various sensors and such that the ECM on a FI and/or Turbo-FI vehicle needed, and as such an originally carbureted engine wouldn't have that. Thus I'd always wondered about swapping in the FWD motor into a RWD car.

But if the sensors, etc., could just be put on the existing original engine... ahh . . . different story entirely.

05-17-2005, 08:20 AM
The later 3800 was a bit different, being on center and such.

It might be a little more difficult then if you use the setups from the mid80s on the 3.8 RWD.

The turbo EFI stuff will bolt right up.

05-23-2005, 10:09 PM
found this on the other board, nice wite up and good info

05-24-2005, 12:50 PM
... and another one to add to that:


05-25-2005, 12:10 PM
Nice Ken, i missed that one