2.8 to 3.8 V6 swap

[brokexj]

Just thinking about a swap from the 2.8. Just omit the obvious solution (buy a XJ with a 4.0) and has anyone done it? With the wiring harnesses for plug and play now a little cheaper, how about a RWD 3.8 with the top end off of Pontiac SSEI supercharged 3.8? Motor mounts shouldn't be too hard to mock up, Turbo 350 or 700 r4 with a 231. Price wise for the parts, have a decent yard for parts so that isn't a huge concern. If a 401 can fit in a MJ, I can probably get a 3.8 in a XJ. MY real question, has anyone used the plug n play harnesses? This is what 8 hours of sleep in three days does to your thinking processes!

 

[ROBZ95Xj]

There been a few that have swaped in a 3.4 V6 out of a camaro. Do a search on "3.4" and youll find plenty of info.

 

[Grizzley]

Is the extra .4 worth the aggravation? 3.8 is a 90* block, kind of tight but doable. 3.4 is a plug and play. Same block as the 2.8, just factory stroked and bored. Get one out of a pontiac Firebird. Use the MPI from that or use a TBI off a Chevy 2.8 and change the two injectors to 4.3 injectors. Why make things hard when you'd rather be wheeling it?

 

[dan89XJ]

The swap is Doable ! FWD 3.8 blocks bolt up to the 2.8 transmissions ! Ive seen the swap done.. do a search and you'll find something.

But, I'd say it'll be alot of work and time, but sure would be awesome. The power and efficenty of the 3.8 superchargers would be great for wheeling. They are also fairly light motors. I'd do it myself but no time or funds.

 

[Big C]

The swap is Doable ! FWD 3.8 blocks bolt up to the 2.8 transmissions ! Ive seen the swap done.. do a search and you'll find something.

But, I'd say it'll be alot of work and time, but sure would be awesome. The power and efficenty of the 3.8 superchargers would be great for wheeling. They are also fairly light motors. I'd do it myself but no time or funds.

It'd be tough to adapt the 3800's supercharger to a RWD application, because the inlet juts streight into the firewall in a RWD vehicle. I frequent a lot of F-body boards (96-02 models had the 3800 standard) and a surefire way to get people ticked off is to a 3800 supercharger swap into a RWD 3800 engine!

 

[brokexj]

What web site was that at? Still interested. I know about the 3.4, that's why I asked about the 3.8. Still haven't made up my mind about keeping this xj. Really don't what to get rid of it, it's got a lot of mods and don't really have the desire to keep a trail only rig. I look but that's the kind of info I was looking for.

 

[houlster]

Few pics and link to more info towards the bottom:

http://www.naxja.org/forum/showthread.php?t=8445

--Dan

 

[hklvette]

I am planning on swapping a 3800SC S2 into my '98 due to better parts availability/ better power potential. The motor i'm using can bolt an electronically hook up to the 4L60E used in late 90s camaros/ firebirds with the 3.8 V6 (same engine sans SC) I'll hook that combo up to a passenger drop 241 so i can use a 12B/D44 combo that I'm getting practically for free. The GM pieces all play nice in the sandbox, but getting all of it to work in an XJ body will be tricky for sure. Not sure about physical fitment, but I know that the S2 engine has a shorter deck height than the previous 3800s so it may fit better.

my $.02

 

[hklvette]

since i fail and can't figure out how to edit my post, I've found out some pieces of information that may be helpful...

First, the supercharged Thunderbird uses the same SC that the 3800SC S2 and S3 use. The T-bird uses what amounts to a 90* elbow attached to the back of the SC to relocate the TB to a better location.
Second, the inlet (I believe) coolant line fitting in a longitudinal setting would be in the back driver's side corner of the engine bay, requiring a bit of plumbing to make it plug in to the radiator.

If all else fails for the intake, the 3800's short length compared to the I6 gives wiggle room to move foward if needed, or as a last
resort, you can always put a hole in the firewall and route the intake under the cowl.