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3.8l swap?

G.P_XJ

G.P_XJ

NAXJA Forum User
Location
Centennial, CO
Becuase my motor has been slowly going out on me i've been looking at some motor swap ideas and options. I would love a v8 but it seems like there are alot of them out there and i want to do something different, So i found out that some chevys and pontiacs had a 3.8L supercharged v6 that makes 240hp and 280ft/tq.

My only problem is i havent found anyone who has swapped in this motor. Have you guys seen it done? would it be a good swap? and are there any companys that make motor mounts for it?

thanks
Garrett
 
Ahh yes, the Buick V6. Used in Pontiac, Chevrolet and Buick vehicles in supercharged and naturally aspirated cars for a long time. You'd want the Series III L67 or the L36 if possible. Wikipedia has a good article on them.
I've thought about the same thing myself.
Issues include but are not limited to:
Wiring the guages
Motor mounts (don't think anyone makes them)
The 60 degree bellhousing (makes it tougher to find a trans / transfer case combo, I think)
and cost.
I say go for it, document it, and let us know how it goes :)
 
There is a guy on comancheclub.com that did this swap. I think his username is jeepcomj. From reading his experience, he used the AX5 trans that comes with the Jeep 4 cylinders and V-6's. It bolted right up, but the trans isnt strong enough for the higher horsepower. I think he had several other issues as well. If you do this, it should be an entire drivetrain swap to be able to keep from breaking too much stuff.
 
The Northstar mostly came in FWD cars, meaning it was mounted across the car instead of parallel with it. This also means that it will be damned near impossible to make a transmission work in the XJ platform, unless you want to somehow make it a front wheel drive vehicle.
If you can find a Northstar from an 04-09 SRX, XLR or STS then you are good to go. Keep the tranny that was attached, I'd think, and have fun!

You could always go with something "easy", by which I mean "been done" like a 5.3L Vortec engine or some other Chevy pickup motor. Another guy on the forums is looking to do a 5.2L Dodge Magnum series engine, which isn't a bad choice.

You could also go with a Volvo inline-6 and add a turbo setup. With tuning, you could get 300+ HP out of it. Fully modern engine, plenty of after market support, very robust with very few if any mechanic problems. I'm a Volvo mechanic, don't recall any "real" problems with these engines at all.
 
There's a guy on pirate who is using an l67 bolted to an aw4 trans in his yj. He used an isuzu rodeo bell housing to bolt it up.

Then you just have to figure out everything else. Wiring, motor mounts, cooling etc

I had a 97 grand prix gtp with the 3800 supercharged in it...stupid fast for a 4 door fwd family sedan. Had 2500 bucks into that car and I could beat ls1s with it :loveu:
 
yossarian19 said:
The Northstar mostly came in FWD cars, meaning it was mounted across the car instead of parallel with it. This also means that it will be damned near impossible to make a transmission work in the XJ platform, unless you want to somehow make it a front wheel drive vehicle.
If you can find a Northstar from an 04-09 SRX, XLR or STS then you are good to go. Keep the tranny that was attached, I'd think, and have fun!

You could always go with something "easy", by which I mean "been done" like a 5.3L Vortec engine or some other Chevy pickup motor. Another guy on the forums is looking to do a 5.2L Dodge Magnum series engine, which isn't a bad choice.

You could also go with a Volvo inline-6 and add a turbo setup. With tuning, you could get 300+ HP out of it. Fully modern engine, plenty of after market support, very robust with very few if any mechanic problems. I'm a Volvo mechanic, don't recall any "real" problems with these engines at all.
Click to expand...

The Caddy motor shouldn't be much of an issue, there was somebody out there making parts to bolt them into different pre-WW2 hot rod chassis' as well as all sorts of neat hot rod goodies too:thumbup:

G.P_XJ said:
My motors on the brink of blowing up here any day, and a stroker would be nice but for how much i would spend on one i could get something bigger and better
Click to expand...

Would that swap be any cheaper and less work than doing what's required to stroke the stock motor though, especially when you would end up with a much smaller motor that a stroker would leave you with? At least with the Northstar motor you would have access to a parts to convert if needed.
 
The FWD 3800 uses the GM Metric bellhousing. This is the same as was used in the Cadillac FWD 4.x engines (pre-Northstar), the Fiero, the Isuzu Trooper, and a couple of other vehicles. The Cadillac Northstar is modified version of this pattern. Anyway these are all FWD applications except for the Isuzu.

The 3.8L from the GNX was RWD and has a BOP bellhousing.
 
One of the writers for JP magazine put a northstar in a flatfender 5-7 years ago. Turned out sick. Probably some info on their website.
 
Renegade XJ said:
for 240HP.....why not just do a stroker?
Click to expand...

3800s love mods. You could get well over 300 hp without much at all...bolt ons, tune, and maybe rockers or a cam. Plus they are torque monsters just like your strokers, and they'll get 25mpg if you keep your foot out of it (but good luck doing that:D) Also much smaller and lighter than a v8 or stroker
 
dopod said:
3800s love mods. You could get well over 300 hp without much at all...bolt ons, tune, and maybe rockers or a cam. Plus they are torque monsters just like your strokers, and they'll get 25mpg if you keep your foot out of it (but good luck doing that:D) Also much smaller and lighter than a v8 or stroker
Click to expand...

EXACTLY!! thats why i was looking into the 3.8 as a swap
 
The 3.8 would be sweet, no doubt. Like I said - do it, post pics.

Of course, you might be able to put a Boostec or a Bryson kit on a rebuilt 4.0 just as cheap, but that doens't get you the fuel economy of a 3.8
 
you go to a more powerful motor youre gonna break everything else on your rig GPXJ....

^^^^HEAVY right foot
 
http://pirate4x4.com/forum/showthread.php?t=841159
Click to expand...
3800 Bible. Didn't read a whole lot but apparently all these chevys have the same bolt pattern and will mate to the aw4/etc. or at least whatever the xj 2.8 v6 was mated to. Also the pcm harness looks incredibly simple. I say go for it even though I'm just as for a mildly built 4.0 (not stroker) my plan was to run 9.25-9.5:1 compression with a good head and 99+ intake on my renix block and maybe throw in a mild cam in the process for a good ~260 hp and say 300lbft with external mods obviously. Though on the 3.8, exaust intake tune and a 3.4" blower pulley thats a easy 300 hp and god knows how much torque.
 
Last edited:
It's not that hard but completely custom everything. From wiring to motor mounts to headers. When I did mine, I used the ax5 but still had to mod the bellhousing to put the starter bump on the correct side, and tomove the throwout plate back 3/8" to accomodate the thicker flywheel.


Combining a camaro t5 world class with a 93 s10 2.8l t5 would give you a stronger trans that would bolt right up.

Mine was an 86 and I had to put a 4.0 core support in it and use a 4.0 radiator with custom electric fans.

You also ned to bypass the VATS system in order for it to run.

I averaged 25mpg when I was heavy on the pedal, 29 when going easy on it. Mine was naturally aspirated but bored .030 with a torquer cam. Stupid fast, sounded awesome, but ate through 4 or 5 ax5s each within 1k miles of install. Dana 35s held up for about the same. Virtue was I had a ton of spares so I didnt care.
 
i had a 93 regal with a n/a 3800. it was only 170hp, but it would take 3rd gen camaros all day long. TONS of torque, too much for fwd IMO. i went through a trans about every year or more. blew up hard parts in them, especially the final drive. awesome motor though... ran forever and ran strong. to this day, i have never seen a motor that could take a beating like that one and still not miss a beat or burn a drop of oil.
i would love to have a supercharged gran sport or gtp, but i know i'd be dealing with the trans blowing up all the time. the front end took a beating too, too much torque for ball joints and struts to handle when abused.
 
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