Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   YJ Tech Forum (http://www.wranglerforum.com/f218/)
-   -   Cummins 4BT turbo (http://www.wranglerforum.com/f218/cummins-4bt-turbo-98746.html)

yj93ben 06-18-2011 08:55 PM

Cummins 4BT turbo
 
Yippie, they just delivered my next winter project. Just signed for a new/reman Cummins 4bt at my place of business. Came with a spec tag, almost 130 HP and almost 300 FT/lbs of torque.:dance: If I didn't have so much Jeepin' to do this summer, the front end would already be off.

What I'm looking for are links for YJ swaps from 2.5L to the Cummins 4bt 3.9L turbo. PLEASE, and don't take this the wrong way, NO FORUM LINKS, PLEASE! I'm trying to gather information, not opinions. I really don't want to read through 600 post in a thread to find out that only 50 post are about the project.:banghead:

As Joe Friday used to say in Dragnet "just the fact, ma'am" .

MellowYellow89YJ 06-18-2011 10:32 PM

Not a lot of info out there really, you will become a major source of info for others if you do a full build thread. There has been a lot of talk, but few have actually done it. Keep us posted on your build! I love my 4.2, but love the idea of going diesel.

Barrie 06-18-2011 10:37 PM

Check this thread out.


http://www.wranglerforum.com/f118/my...stainless+dash

firstresponder 06-19-2011 03:33 AM

Good luck with the build i know we will all be waiting to see the finished product!

444 06-19-2011 10:42 AM

Will be very cool! I think your only real stumbling block will be the fact that a 4BT supposedly weighs as much as a big block v8!

herbie 06-19-2011 06:20 PM

try cummins 4bt and deisel conversions forum

Driller 06-19-2011 07:42 PM

like idea of 4bt swap. on dieseltruckresource.com some have done the 3.3L swap, weighs 200lb less than 3.9L and uses ax15 trans. may be harder to find one of these engines but is working for these guys and good mileage...Driller

StinkyMud 06-20-2011 05:20 AM

A guy I wheel with has the 4BT hooked up to an AX15 in his TJ and I must say it is a BEAST!!!! Wish I had the know how to do this.. I'd love to go with a diesel.

Good luck with your project, you will be very happy when you're done, I'm sure! :thumb:

yj93ben 07-30-2011 10:19 PM

Quote:

Originally Posted by 444 (Post 1316511)
Will be very cool! I think your only real stumbling block will be the fact that a 4BT supposedly weighs as much as a big block v8!

Ya, I was looking at the weight issue. I figure if I find a pair of factory 6 leaf leaf springs, I should be OK.

Also, just got the axles. 2000 Explorer 8.8 for the rear. 4.56s, ARB locker
Currie Enterprises built to order Dana 44 for the front. 4.56s, ARB locker

billytheyj 07-30-2011 11:15 PM

Quote:

Originally Posted by yj93ben

Ya, I was looking at the weight issue. I figure if I find a pair of factory 6 leaf leaf springs, I should be OK.

Also, just got the axles. 2000 Explorer 8.8 for the rear. 4.56s, ARB locker
Currie Enterprises built to order Dana 44 for the front. 4.56s, ARB locker

Jealous!!!!

YJman 07-31-2011 12:33 AM

Holy crap. Your jeep is going to be unstoppable. :)

IndyJeepMan 07-31-2011 12:59 AM

Quote:

Originally Posted by yj93ben

Ya, I was looking at the weight issue. I figure if I find a pair of factory 6 leaf leaf springs, I should be OK.

Also, just got the axles. 2000 Explorer 8.8 for the rear. 4.56s, ARB locker
Currie Enterprises built to order Dana 44 for the front. 4.56s, ARB locker

4.56 with a 3.9 turbo? What size tires 40"?

Oh and no need to go with leafs in the front, just get some hd longer coils for the front. Between winches bumpers and other things many guys run close to the difference in weight.between the 4.0 and 3.9 and have no weight issue. 300lbs isnt that much..

MellowYellow89YJ 07-31-2011 10:01 AM

Quote:

Originally Posted by IndyJeepMan

4.56 with a 3.9 turbo? What size tires 40"?

Oh and no need to go with leafs in the front, just get some hd longer coils for the front. Between winches bumpers and other things many guys run close to the difference in weight.between the 4.0 and 3.9 and have no weight issue. 300lbs isnt that much..

Being a YJ, leafs are the way to go unless he just want to do a coil conversion.

Ggg 07-31-2011 02:56 PM

I am the guy StinkyMud was talking about, here is a link to my build thread.
http://www.4btswaps.com/forum/showth...d-a-4bt-diesel There is a TON of info on swapping the 4bt into all sorts of chassis, just Google it.
By far the most informative site is http://www.4btswaps.com/forum/forum.php
There are a lot of Jeep swap threads on that site. Don't just limit your search to the YJ as the CJ and TJ frames are all close enough that a lot of the same info applies to the three of them.
Some things to consider before you get started are; intended use, transmission, tire size, driveline.
Some things that may influence your choices are; Legality, check with your state laws to be certain it will be legal, some areas this gets tricky. The 4bt weighs between 800#- 900# depending on accessories etc. The engine size requires some planning to avoid clearance issues. Intended use plays a big part in how the chassis is set up. Transmission choice can be an expensive decision to change. I initially went in the automatic trans route and later changed my mind to use the stock AX15/231 manual, the Cummins flywheel alone is a $800+ part. Driveline, I have seen the 4bt AX15/231 combo spit a D44 rear ARB out the housing.
As far as your gear ratios this all depends on your tire size and intended use. I run 37"-42" tires and 4.56 would be ideal, but I do not use it as a DD and it only highway speeds on rare occasion. If I were to drive mine at highway speeds than 4.11 would be the better choice considering my tire sizes.

yj93ben 07-31-2011 03:41 PM

Quote:

Originally Posted by Ggg (Post 1425684)
I am the guy StinkyMud was talking about, here is a link to my build thread.
http://www.4btswaps.com/forum/showth...d-a-4bt-diesel There is a TON of info on swapping the 4bt into all sorts of chassis, just Google it.
By far the most informative site is http://www.4btswaps.com/forum/forum.php
There are a lot of Jeep swap threads on that site. Don't just limit your search to the YJ as the CJ and TJ frames are all close enough that a lot of the same info applies to the three of them.
Some things to consider before you get started are; intended use, transmission, tire size, driveline.
Some things that may influence your choices are; Legality, check with your state laws to be certain it will be legal, some areas this gets tricky. The 4bt weighs between 800#- 900# depending on accessories etc. The engine size requires some planning to avoid clearance issues. Intended use plays a big part in how the chassis is set up. Transmission choice can be an expensive decision to change. I initially went in the automatic trans route and later changed my mind to use the stock AX15/231 manual, the Cummins flywheel alone is a $800+ part. Driveline, I have seen the 4bt AX15/231 combo spit a D44 rear ARB out the housing.
As far as your gear ratios this all depends on your tire size and intended use. I run 37"-42" tires and 4.56 would be ideal, but I do not use it as a DD and it only highway speeds on rare occasion. If I were to drive mine at highway speeds than 4.11 would be the better choice considering my tire sizes.

I'm planning(on paper)to end up with Cummins 4bt, NV4500, Atlas II or D300, Ford 8.8 rearend and a Currie Dana 44 frontend with 4.56s and ARBs in both. thought about spooling the rear, but I do to many tight trails. My rig now is pretty much a dedicated trail rig, I mean it's still street legal and licensed, I just don't drive it on the streets. my tire size is 34/9.50X15 Swampers. I might go a little tall, but I like the narrow tires.

Thanks for the links. I have a lot of reading to do.

Ggg 07-31-2011 05:02 PM

Very good idea to do as much planning on paper as you can. You will not need a really low gear in low range, my stock 2.7:1 is plenty for my use. I have driven one that had a Rubi 4:1 and it was too much gear reduction.
I would recommend alloy axle shafts in your axles. To give you an idea of available torque I just broke my front D60 Detroit locker all to heck and the AX15/231 are fine, yes I run alloy shafts with drive slugs.
I think you will have no problem coming up with a front spring combination that will work nicely. For reference I ended up using 78-79 Bronco front springs, TJ rear springs, but I think the rears are a bit too soft.

yj93ben 08-01-2011 08:50 PM

Quote:

Originally Posted by Ggg (Post 1425961)
Very good idea to do as much planning on paper as you can. You will not need a really low gear in low range, my stock 2.7:1 is plenty for my use. I have driven one that had a Rubi 4:1 and it was too much gear reduction.
I would recommend alloy axle shafts in your axles. To give you an idea of available torque I just broke my front D60 Detroit locker all to heck and the AX15/231 are fine, yes I run alloy shafts with drive slugs.
I think you will have no problem coming up with a front spring combination that will work nicely. For reference I ended up using 78-79 Bronco front springs, TJ rear springs, but I think the rears are a bit too soft.

Ya, I'm thinking factory 6 pack leaf springs in the front and 5 pack leaf springs in the rear.

When you said the rears are a little soft, were you referring to on or off-road?

Ggg 08-02-2011 01:40 PM

My rear springs are kinda soft in a general sense, but it may be my shocks. The Jeep rides very smooth on the road, but if I hit a dip in the road the rear seems to oscillate more than the front. Also when hill climbing the rear will start bouncing a lot when the wheels spin.

Ibuildembig 08-02-2011 01:47 PM

Factory 6 leaf fronts? Never seen any on a YJ....4 in front and 5 in rear all day long

yj93ben 08-02-2011 04:20 PM

Quote:

Originally Posted by Ibuildembig (Post 1431919)
Factory 6 leaf fronts? Never seen any on a YJ....4 in front and 5 in rear all day long

Big, they're not real popular, but they're out there. Intended for the rear, but will fit the front.

1987-96 Wrangler YJ series heavy duty rear - 1080 load, 237 rate (measures 22-11/16 x 22-11/16, 6 leaf, 2-1/2" wide): General Spring offers leaf springs, coil springs, lift kits, leveling kits

1987-1996 Jeep Wrangler - Leaf Spring (Rear - 6 Leaves) - 97-567 | $113.29

Most Jeepers steer away from them, due to they're a little stiffer than we normally want. However, with the added weight it should be a wash.

Ggg 08-05-2011 10:18 PM

We used to use them with snow plow applications.

superduty_5.9 08-06-2011 10:38 AM

I love what you are planning but why tag and insure if you don't drive on the road? I would think it's a waste of an awesome machine (4BT-Jeep) to not run down the road whenever I felt like. There are probably hundreds of 4BT Jeeps out there but unfortunately most info is in forums. Most don't take the time or money to dedicate a site to just one thing.

Ggg 08-06-2011 10:34 PM

In my case the Jeep is to high for the laws. Even if I put a set of 235/85/16 tires on it I'm 4" too high. I insure and license it because some outings I go on require insurance and valid license plates.

yj93ben 08-12-2011 09:05 PM

Quote:

Originally Posted by Ggg (Post 1446453)
In my case the Jeep is to high for the laws. Even if I put a set of 235/85/16 tires on it I'm 4" too high. I insure and license it because some outings I go on require insurance and valid license plates.

I'm sure, by the letter of the law, a good portion of our rigs are not street legal. So, until I get told to park it, I'll keep it licenced and insured and drive it when I feel like it. I got pulled over in it earlier this year for a seat belt infraction. When the state trooper walked up and told me why I had been stopped. He looked down and discovered I was wearing belts, Simpson lap belts. "Oh, I see you're wearing belts after all" the officer said. Smiled and told me to have a nice day.:thumb:

jeep534 02-25-2012 10:12 AM

traction bar
 
Quote:

Originally Posted by Ggg (Post 1431906)
My rear springs are kinda soft in a general sense, but it may be my shocks. The Jeep rides very smooth on the road, but if I hit a dip in the road the rear seems to oscillate more than the front. Also when hill climbing the rear will start bouncing a lot when the wheels spin.

4X4REVIEW.COM: Sam's Off-Road Traction Bar


this type of traction bar will help plant the rear if the ride height is correct soft suspension in the rear is better I dont have enough height and too stiff springs on the rear but am am not having any wheel hop

Ibuildembig 02-25-2012 10:19 AM

^^^^brought out the super old skool traction bar :)


All times are GMT -5. The time now is 08:37 PM.