Jeep Grand Cherokee + Cummins (3.9L) ISBe + Allison 1000-Series = :)

[HoleshotHolset]

So is that isb 3. 9 a 16 valve?

Yup.

I am wondering if a 1. 9 VW turbo'ed engine might have been a slightly more adaptable candidate though?

Nope. 1. 9L pushing a 4200 pound Jeep?!... it'll be working its heart out all the time. The Cummins will never even begin to break a sweat. Besides, anyone can put a little plant in a big engine bay... the challenging aspects of this project is at least 1/2 the fun.



Matt

 

[Matt S]

So are you driving that monster around yet?

 

[HoleshotHolset]

So are you driving that monster around yet?

Not even close. I got sidetracked with 'farm chores' and maintaining daily drivers last weekend. Grrr! I really gotta get going on that thing... even if it means neglecting other projects.



Matt

 

[TurboTweaker]

and he got married! that took some time out of things

 

[Matt S]

Congrats to you and your wife! Now get back to work.

 

[HoleshotHolset]

Thanks for the congrats. She's totally supportive of this insane project.



Here's a few pics to show how the ISB doesn't exactly fit in the engine bay. It still has to go about 3" lower, but the oil pan is hitting the drag link and track bar. :-laf



Matt

 

[JasonCzerak]

heh, should just leave the hood cut open, it would look bad @$$ with that 4 banger ratting thought the hood like that.



kinda like a hotrod deal.

 

[zstroken]

What about a 4l80E in there for a transmission, should give you some room and it is a fairly stout unit for what your using it for. Heck it hold back the massive power of a 6. 5 turbo.

 

[Matt S]

Here's a few pics to show how the ISB doesn't exactly fit in the engine bay.

You just need a hood scoop on that puppy!

 

[RMeskimen]

Hell, just go hoodless. You are going to have to cut a hole for the 4 feet of dipstick to go through anyway! lol Interesting project. It's a bigger bite than I could chew but very impressive nonetheless. Good Luck.

 

[HoleshotHolset]

Well - I dropped the drag link and the track bar last night with a pickle fork and got 'er to drop another 2-3". Now the front axle pumpkin/tube is in the way. haha



I didn't take pics, though since I'm starting to think that it's time to use the Sawzall on the ZJ's firewall and transmission tunnel to move it back and allow the rear sump to drop behind the axle like it does on our Cummins powered Ram trucks. (For a while I thought it might be possible to do front sump... pipe dream!)



I've got a 3-day weekend to play in the garage - I'll be sure to post pics after the dust has settled. Things are going to start getting ugly, folks. :-laf



Matt



On edit:

I've read about a guy on the Yahoo! 4BT group that claims that the hood can shut without modifying it at all if you get the engine in there 'just right'. He didn't say how much of a massage was rendered to the firewall/tunnel, however. He also claims that at least 4" of suspension lift is needed. I concur, even if I was originally hoping to leave it at OEM height to keep things simple and looking totally stock from the outside. He also wrote about ways to get around the drag link / track bar issues - which I'm VERY interested in hearing more about. I've emailed him, but he hasn't responded yet.



As for the 4L80-E - I think it is a great transmission, but I'm unaware of any versions that come with an SAE #3 bellhousing. This little ISB170 has a rear gearcase and an SAE #3 bellhousing bolted to it. The Allison LCT-1000 came with my engine as a package deal... so it's good to go - just gotta make room for it!

 

[moparguy]

Dry sump? Might pick up a couple hp.

 

[ilovetrains]

Matt, how much do you need? You can move the axle forward 2-3 inches with adjustable control arms. You would need to loose the front bumper and go with something custom.

 

[Sled Puller]

2" of suspension, then hood scoop the rest. Although 4" would look pretty nice, and not be outrageously high.



Say on that dry sump, wouldn't it have to be driven by a belt? And that would take less HP than an in pan pump?





I wish you'd use the Jeep transmission, so I dont have to do so much work when the day comes..... :-laf

 

[Sled Puller]

I'm gonna set it up like an old Letourneau earth mover - DC electric drive!

Funny you mention that, we have one, but a much later model, Detroit Diesel with an- ALLISON AUTOMATIC!! lol!! It still has electric on the selfloading chain and steering of all things. Toggle switch steer, oh, and dont let rpm fall, or the gen wont make enough juicie to steer.

 

[Alphacowboy]

this is what it would look like iwth a 3" lift... not alot different...

#ad




I know its not the same body style, but a 5. 5" lift really aint that much either... looks damn good...



#ad




heres one on a D44 front and D60 Rear!



#ad

 

[HoleshotHolset]

I didn't get a chance to turn wrenches on the Jeep at all during the 3-day weekend - I'll start another thread and link to it from this one to explain why. Here's my latest Jeep project diversion... my daily driver needs work.

Matt, how much do you need? You can move the axle forward 2-3 inches with adjustable control arms. You would need to loose the front bumper and go with something custom.

That's a neat idea - how does moving the axle forward affect the coil spring alignment? Do you have to move the upper spring perch forward as well? The front bumper on that thing makes the OEM bumpers on the Dodge Rams look rugged - its horrible.

Dry sump?...

I have ZERO experience working on anything with dry sump. I don't want my future daily driver to eat itself from my inexperience. It is a good idea, though. Thanks!



Like I said before, I'm really disappointed that I couldn't work on the Jeep - I've got too many irons in the fire these days.



Thanks for the pics of lifted Jeeps - I lifted my brother's old '98 ZJ 3" with coil spring spacers. That thing rode like a Caddy... I want it to ride a bit stiffer than that thing did. I really think 4" is the minimum... I'll know more once I can get back into the garage after the other emergencies subside. The firewall might not have to be cut all that much, but I will have to massage the transmission tunnel to make room for the Allison. The big mounting tabs behind the bellhousing stick out a lot. Even though I'm not going to use them, I'm not about to grind them off.



Thanks,



Matt

 

[ilovetrains]

You can go at least 2 inches forward without putting much stress on the coils at all. They will center and adjust without difficulty. think of it this wa, sith a solid axle and 8-10 inches of travel, the coils are already adjusting that much latterally and you never noticed becauase that is the great thing about coil springs.



We just lifted a ZJ 4. 5 with a RE 4. 5 kit. It is not as tall as you might think and we plan to run 33's on it.



ARB makes a serious bumper for the ZJ. Local guy runs one, it is tough.

 

[HoleshotHolset]

That's a good point... so do all 4 arms need to be replaced?

I've looked at a few lift kits out there and did some research. Up to 4" of lift, lots of folks seem to think that the OEM arms can be used. You can then use the front coils in the back and just relocate the rear track bar.



When I get the axle clearance solved, I'm still up against the track bar/drag link issue. I've never had to make steering components before... or for that matter - tried to stuff an engine into a bay that was NEVER designed for it. :-laf



Rubicon Express seems to be very highly regarded in the Jeep world. Since I'm lifting the ZJ just to make room for the engine - I kinda don't want to spend an arm/leg on a kit when I'd really like to just leave the suspension / ride height alone in the first place. You gotta do what you gotta do, though.



Thanks,



Matt

 

[ilovetrains]

yes - you would need to do all 4 arms. I think it is debatable about whether you have to do the arms with 4 inches of lift. We are using the RE 4. 5 kit. I like the RE stuff, but you can defenitely find cheaper. Rusty's Off Road used to have some pretty budget kits, but I usually see Sky-Jacker as the cheapest alternative.



ALso keep in mind, you need to probably do a drop Piman and may have some problems with moving the axle that far forward. My TJ, we moved the axle 1. 5 inches forward with no problem whatsoever. The front driveshaft was still plenty long.



It makes for more of a project, and may not be legal in your state (have to check that yourself) but you could elimnate some of your steering problem by going with hydraulic. You would only need a single link from one side to the other.