cummins in a cherokee

[gotmike]

finally got my fuel tank in... problem is... i don't know what it came out of... it bolted in so easy it's not even funny... and i got my L.E.D's in where my factory tail lights used to be... i'll get pic's up later... now i just need to clean out the interior completely and get it blasted and painted/herculined... that's going to be a dirty weekend though

[gotmike]

here's a link to some more pics... including one of the tail lights

http://s239.photobucket.com/albums/ff209/mikehaid/cherokee%20project/?start=all

[gotmike]

got my onboard air up and running too... pics are on the link above...

[The PIG Smith]

Frame Questions

the dodge frame is really very close to the same as the jeep frame... it's just heavier duty...

As I am thinking about a Cummins 6BT Conversation (very long term project) I am concerned about my Jeep Frame and have some questions.
When you say the Dodge Frame is heavier than the Jeep frame, I am assuming that that you are comparing
a Jeep Cherokee/Wagoneer style frame to a Dodge 3/4 ton pickup truck frame.

I am considering a Cummins 6BT in a J truck.
So, would like to think a 3/4 ton Jeep frame is about the same strength as a 3/4 ton Dodge frame.

There has been some discussion on this forum in the past that if a person uses a Jeep Frame for a 6BT swap,
that some reinforcing of the frame is required (boxing?)
But, I will assume the folks that report this modification requirement is speaking about the 1/2 ton rated Cherokee/Wagoneer frame and not the J Truck frame.

I am writing to ask that you elaborate on the why you felt you needed to use the Dodge frame.
What does the Dodge frame provide?
Deeper frame rails?
Thicker material?
Stronger steel?

If you convince me that a Dodge Frame is the way to go, would a frame from a Dodge 2500 gasser be the same as a powered be a CTD?

[gotmike]

the frame on the jeep was 4 or 5" channel... the dodge frame is 8" channel it's heavier steel and it has some very stout cross members... it is definately a stronger frame... plus it's got a dana 70 rear end... i would think that the frame on a newer gasser would be strong enough... but i don't know off the top of my head... and i could be wrong but i don't believe there's much difference in the frames between the half ton or 3/4 ton jeep frames just a difference in the springs and axle... are you planning on lifting the truck or keeping it low for towing? if you are going to lift it as well you would be better off getting a newer frame because once you do the swap you're already lifted... and i had to shorten my frame but you may be able to find a single cab short box to pretty much match your current wheelbase... it's really up to you how much money you want to spend and how much work you want to do...

[JeepsAndGuns]

Just saw your jeep in a issue of (I think) diesel power.
I was wondering if it was anyone on here.

[The PIG Smith]

the frame on the jeep was 4 or 5" channel... the dodge frame is 8" channel it's heavier steel and it has some very stout cross members... it is definately a stronger frame... plus it's got a dana 70 rear end... i would think that the frame on a newer gasser would be strong enough... but i don't know off the top of my head... and i could be wrong but i don't believe there's much difference in the frames between the half ton or 3/4 ton jeep frames just a difference in the springs and axle... are you planning on lifting the truck or keeping it low for towing? if you are going to lift it as well you would be better off getting a newer frame because once you do the swap you're already lifted... and i had to shorten my frame but you may be able to find a single cab short box to pretty much match your current wheelbase... it's really up to you how much money you want to spend and how much work you want to do...

Thank you for your answers.

I am seeking a Tow Rig, so no lift for me.
But I was thinking some sorta of body was required because the 6BT is such a tall engine.

You are correct, J10 and J20 are the same.

8 inches is a deep frame.
I went out and looked at my J20's frame under the cab
It measures roughly 6.5"
I think finding a CTD Frame maybe a challenge
I am not worried about how much work is envolved, (well, I am kinda/sorta am)
as much as how much $$$ it would take to convert a Dodge CTD frame to my Jeep body.

[gotmike]

it's actually much easier then i thought it would be... but it's up to you... just go to a junkyard and do some research... take some measurements...

[J10Mike]

Sweet conversion...But, I'm just curious. Have you taken that heavy front end off road into some serious mud?
Being the owner of a Dodge CTD 4x4, I know that the engine weighs in excess of 1200 Lbs.
In fact, while off road just goofing off, I got stuck going thru a mud hole...Ok, a big mud hole. Granted, my axles are stock and open. But, it wasn't deep enough to get stuck. My old J10 wouldn't have gotten stuck. Yet, my CTD sank deep in the mud up front.
Guys, unless you have an ARB locker in the front D60 and at least a LSD in the rear, that 5.9 6BT is not a good conversion for off road use.
Been there, done that.
It is a great conversion for a FSJ that tows heavy loads. Just don't take it off road and expect it to glide thru those mud puddles...It's just too heavy.

[jdaniel83]

My friend had a similar conversion and he had some of the same issues. His Wagoneer had a lot of power and could pull a house down, but it lost a bit of it's off-road capabilities because of the added weight. Good thing for him was that he didn't do a whole lot of off roading, but one time he had to he felt pretty stupid when I had to get my dad's stock '62 Willys CJ5 with the little 4-banger and Army tires to pull him out. He really felt bad when I went through the same hole he had just gotten stuck in easily, but then again those little Jeeps can go through just about anything.

[gotmike]

why do you think i have 14.5" wide tires on it??? and i don't really like mud... it plays hell on your seals and axles... i'd rather crawl over rocks and climb hills... we have some pretty good trails around here for that kind of thing... plus with the wagon, the weight is a little more balanced... i got stuck once with the pickup and the main problem was no weight in the back i couldn't get any grip with the rear tires... with the jeep setup and all my tools and straps in the rear, i've got plenty of weight on my rear axle and therefore quite a bit of traction...

[gotmike]

you might also check out http://www.cummins-conversion.com

and if you do go with the 6bt and don't hook up a/c for the jeep you have the option of using the pump for an onboard air system... i did it on my jeep and it works phenomenally...

[Mikel]

When I parted the 1991 W350 CTD Ram that provided the axles for my J300, I was amazed at how wimpy the frame was and how much it flexed without a body on it. It was C-channel from end to end, yes, taller than a J-truck´s, but a J-frame is half boxed. The spring mounts didn´t look any stouter than those in a non-post mount truck. IIRC, both frames were 3/16" in thickness.

http://www.turbodieselregister.com/forums/1st-generation-ram-forum-1989-1993/177224-free-frame-ct.html#post1700218

As I am thinking about a Cummins 6BT Conversation (very long term project) I am concerned about my Jeep Frame and have some questions.
When you say the Dodge Frame is heavier than the Jeep frame, I am assuming that that you are comparing
a Jeep Cherokee/Wagoneer style frame to a Dodge 3/4 ton pickup truck frame.

I am considering a Cummins 6BT in a J truck.
So, would like to think a 3/4 ton Jeep frame is about the same strength as a 3/4 ton Dodge frame.

There has been some discussion on this forum in the past that if a person uses a Jeep Frame for a 6BT swap,
that some reinforcing of the frame is required (boxing?)
But, I will assume the folks that report this modification requirement is speaking about the 1/2 ton rated Cherokee/Wagoneer frame and not the J Truck frame.

I am writing to ask that you elaborate on the why you felt you needed to use the Dodge frame.
What does the Dodge frame provide?
Deeper frame rails?
Thicker material?
Stronger steel?

If you convince me that a Dodge Frame is the way to go, would a frame from a Dodge 2500 gasser be the same as a powered be a CTD?

[ob1jeeper]

When I parted the 1991 W350 CTD Ram that provided the axles for my J300, I was amazed at how wimpy the frame was and how much it flexed without a body on it. It was C-channel from end to end, yes, taller than a J-truck´s, but a J-frame is half boxed. The spring mounts didn´t look any stouter than those in a non-post mount truck. IIRC, both frames were 3/16" in thickness.


http://www.turbodieselregister.com/f...ml#post1700218

There are many significant differences in the two frames...
- While the Jeep frame may be boxed, it is:
1) of lighter material thicknesses
2) has a much smaller section modulus than the open C-channeled Dodge frame

- Additionally, the Dodge frame is made of HSLA steel, where the Jeep frame is simply stameped cold rolled steel.

- Finally, the Dodge frame has been designed to spread the stresses caused by a engine of nearly double the weight of the one the Jeep frame was designed to handle, and to handle the torque pulses of that engine.

There is absolutely no comparison, and no question that the Dodge frame would be more durable in a CTD application.

[Mikel]

There are many significant differences in the two frames...
- While the Jeep frame may be boxed, it is:
1) of lighter material thicknesses

I´d like to mike both frames, but the Dodge frame I junked seemed to be .188, just like the Jeep frame.

2) has a much smaller section modulus than the open C-channeled Dodge frame

If I´m correct about the thickness, there is no way the boxed part of the frame has a lower moment of inertia than the front half of the Dodge frame, even with an extra 1" or 1.5" in frame height

- Additionally, the Dodge frame is made of HSLA steel, where the Jeep frame is simply stameped cold rolled steel.

What is your source on this? And in 1990?

- Finally, the Dodge frame has been designed to spread the stresses caused by a engine of nearly double the weight of the one the Jeep frame was designed to handle, and to handle the torque pulses of that engine.

There is absolutely no comparison, and no question that the Dodge frame would be more durable in a CTD application.

The Dodge frame has more reinforcement in the engine area (in the form of massive crossmembers), which the Jeep frame never needed because of the lighter engines that were used, and the lower moments that the engine mounts applied to the frame.

Regards,
Mikel