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Jeep 4.0 I-6 in a BII?


Beanmachine7000

Well-Known Member
Joined
Jun 5, 2008
Messages
2,007
City
Tennessee
Vehicle Year
1991
Transmission
Manual
I was kinda wondering if anybody thinks a I-6 engine from a Cherokee would fit in a BII without too much problems (I think I'm just asking for it here, lol...) I found a pristine engine in a not so nice donor Jeep for real cheap, kinda wondering about the feasability of this project, lol...
 
with custom cooling its very delible.
 
Meaning, rear mounted radiator or just adjust the mounting of where it is, because I don't wanna turn this into a full on trail rig just yet...
 
i would offset a stock hd cooling ranger radiator under the hood with a modded mark8 fan on it.


the jeep 4.0 is an awesome engine. should also get similar economy of a ford 4.0 all things being equal.
 
That's pretty much what I was thinking about, the jeep 4.0 is a little stouter than the ford 4.0 isn't it? I've heard (and felt) that it has gobs of torque, but I've never driven a 4.0 ranger so I couldn't really compare... Thanks for all your help... hopefully, there will be an nice Jeep 4.0 in my BII by the end of summer... I'll think I'll back it up with a manual tranny, just cause i've never had good luck with autos, lol...
 
yeah, its definatly a killer engine...if you put the stroker kit on it its a monster.


i would rate it above the ford for sure but, i would not replace a good ford 4.0 with one. not worth the hassel. but if a had a jeep unit laying around and my ford died, i would definatly use it.
 
What I've been looking at since the whole reason I bought my BII, was an engine rebuild and swap, but now I think I'm gonna go for the Jeep and stroke it out to 4.5l, during my rebuild... I'd really like to keep this a streetable engine, but I don't think gas will be too bad, my DD used to be an LT1 Camaro, so I'm used to paying out the nose for gas, but the Z28 doesn't go camping :( I'm guessing it's time to research what kind of options I have with a Jeep swap... I'm not sure If I really want to do an SAS right now, being as it would be a DD for a couple more years, would this be neccesary or not? thanks
 
depends....seems the old lt1's got good milage to me.


i would rather run a current 5.3 then the 4.0. if sas is an option then skys the limit for engine choices.
 
I really wouldn't want to do an SAS because 1. I won't have the (extra) money this summer (don't wanna cut back on my camping time, lol) and 2. I just don't think I'll ever get into anything I'd ever need more than what a little lift would give... and Yes LT1 does get good mileage, now it's not a 4-banger kinda mileage but on highway trips I could get up to 20 MPG... I think 22 mpg was my best one time I was doing way over the limit though... The Camaro likes to be driven like a V8 sports car though (or maybe I just wanted to drive it that way) and that killed my mileage I usually average between 14-15 mpg probably 80 % city driving...
 
So, I've done a little research on the 4.0 stroker, and I;m thinking I'll just do a transplant, most people doing a stroker are getting numbers around 250 hp and 300ft-lbs. I really don't want that extreme of a ride... maybe one day though :)
 
We all know what I-6 you mean, but is it better than what Ford 4.0? OHV or SOHC. I had a few 4.0L Jeeps and even though they weigh less, my Ranger's 4.0 SOHC is much stronger in stock form. Of course, the rest of the truck isn't as off-road capable but we can fix that.
 
Probably the OHV version.. I'm not really sure about the I-6, it all depends on if I get just an engine or a donor vehicle which engine goes in... looking at either one right now... I don't really want to have to find every little part to swap in the I-6, and I know my stuff would bolt up to the Ford without having to have a donor truck... I've driven a 4.0 equipped jeep before and it had some pull to it, but never had the joy of driving the 4.0 Ranger (yet)...
 
tried it in my '84 Ranger.

The pics are enormous so I'll just link them:

http://www.brivers.net/dkamerad/ledd/100_0915.jpg

http://www.brivers.net/dkamerad/ledd/100_0918.jpg

These pics are about as far as it'll go. If you doghouse the firewall it'll fit fine, otherwise it doesn't sit low enough to get the tranny in due to the passenger drop bracket. even if you clearance that it still has to go farther back in because the oil pump hits the cradle bracket. but other than that it would fit really nice, even room for a conventional radiator up front.

When I attempted it it was well beyond my skills and abilities, if I did it now I could pull it off, but not then. So a 302 it was.

It's doable though. Don't be afraid to cut and do some sheet metal work.

*edit: Do the throttle body upgrade and add some good headers. Really wakes them up. I was pretty impressed what it did to my friends Jeep. Much more responsive and plenty of power to push 38's with 4.10's (maybe? I just really don't think he had gone to 4.56.. hmm I'm almost certain it was a stock gear... anyways-) around very well.
 
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I'm having trouble seeing that the Jeep 4.0 can be much different than a pushrod Ford 4.0. They have nearly the same bore/stroke. They have the same peak torque which means they are getting the same force out of the fuel. The Jeep lists it peak at 4,000 and the ford at 3,000 for the year I'm looking at. The Ford 4.0 makes 200ft# at 1,000rpm--no way that Jeep motor is going to do any better. The Jeep makes 30 more HP, but does it at a higher rpm--both show 125psi MEP at max power and 140psi at max torque. They appear to be the same engine--one in a row one in a V. I can't think of a bigger waste of time and effort.

I didn't look at the transmission ratios on the Jeep. Since everyone has a better first gear than a Ford, I wouldn't be suprised to find the perceived difference there.
 
I had a 1998 Cherokee with a 4.0 and currently have a 1998 Exploder with the SOHC 4.0. Apparently the 98 Jeep 4.0 was rated to 200hp and the 98 SOHC 4.0 was rated at 215. That being said, the Cherokee was about 3/4 the weight of the Exploder, so it seemed more snappy. In reality, the were about the same. The only thing I think the Jeep 4.0 may have had over the Ford was the ease of working on it. I did encounter cooling issues with the cherokee, because the stock cooling system just didn't cut it. I eventually put in a three row radiator and never had any problems after that. Both have been great motors to me, but it would be really cool to see a I6 4.0 in a RBV of any kind.

100_0346.jpg

________
video reviews
 
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