Cummins 5.9 L swap

[WillysDriver]

I've been away from the fullsize Jeep scene for a few years but am back full force with a new toy. The 360 drank a bit to much fuel for my liking so I started looking into a diesel swap. I had a line on a cheap donor 1991 Dodge 250 with the 12 valve Cummins 6BT. The swap was a bit challenging but it now looks almost stock sitting under the hood. Any questions or comments let me know.

http://rides.webshots.com/album/555968460CkdOST?vhost=rides

[Ristow]

very impressive!

did you keep the o/d tranny? if so how much did you shorten the rear drive shaft?

[ohioj20]

Great swap! Looks like a lot of hard work went into that! That is what kept me away from going the 3.9/5.9 route. The 6.2 diesel fits in just nicely! Nowhere near as a good motor as a cummins, but I'm not looking to tow, just want the fuel improvement!

[jeepmj_tj]

I've been away from the fullsize Jeep scene for a few years but am back full force with a new toy. The 360 drank a bit to much fuel for my liking so I started looking into a diesel swap. I had a line on a cheap donor 1991 Dodge 250 with the 12 valve Cummins 6BT. The swap was a bit challenging but it now looks almost stock sitting under the hood. Any questions or comments let me know.

http://rides.webshots.com/album/5559...ST?vhost=rides

wow, I'm in the middle of the exact same swap. 92 12 valve, going in a 79 j20. I actually pulled the cummins out today!!!!!


I have loads of questions.

did the stock intercooler fit behind the muscle grille?
do you have any close up pics of your engine mounts?
what are you using for your heaterbox/core. did it effect the underdash ac?

did you modify the stock gas tank with an electric fuel pump?

what gages did you deside to use?



thanks

im sure ill have more questions.


joe

[crazydog]

wow, I'm in the middle of the exact same swap. 92 12 valve, going in a 79 j20. I actually pulled the cummins out today!!!!!


I have loads of questions.

did the stock intercooler fit behind the muscle grille?
do you have any close up pics of your engine mounts?
what are you using for your heaterbox/core. did it effect the underdash ac?

did you modify the stock gas tank with an electric fuel pump?

what gages did you deside to use?



thanks

im sure ill have more questions.


joe

Dodge did not add the intercoller until the 91.5 came out. So, he may or may not have had an intercooler. Not sure why you would need a electric lift pump, the mechanical lift pumps are usually more than adequate. You could add a piston pump to replace the factory diaphragm pump. These can be found on eBay quite often. As far as gauges, I will be using Isspro gauges when I swap a 4BT in. Not sure about the rest.

[jeepmj_tj]

Dodge did not add the intercoller until the 91.5 came out. So, he may or may not have had an intercooler. Not sure why you would need a electric lift pump, the mechanical lift pumps are usually more than adequate. You could add a piston pump to replace the factory diaphragm pump. These can be found on eBay quite often. As far as gauges, I will be using Isspro gauges when I swap a 4BT in. Not sure about the rest.

in his pictures i noticed he is using the intercooler pipes... the non intercooled motors had a square metal intake tube that came up over the valve covers.

for some reason i was thinking there was also an intank fuel pump as well as the lift pump on the engine...

[WillysDriver]

This swap was done on a shoestring budget so many parts were salvaged off of the donor truck. I prefer to use what I have rather then have custom parts built.
I added some more pictures to maybe help answer some questions. This Jeep does have a lift on it so that helps with axle clearance. I will have to add a leaf to the front end to help the springs. It's too bad I need to add a leaf, the Jeep rides alot better now actually with the extra wieght. I used an '89 Dodge Cummins 4wd transmission that originally had an NP205 on it. The Jeep NP 208 slid on but due to the Dodge T-case adapter housing being longer it caused the T case to hit the Fuel tank. I have removed the mud colecting frame rotting skid plate off of the tank and moved the tank backwards an inch. Due to this I had to shorten the rear shaft and lengthen the front. I still need to sort out a 4wd shift lever because of the T case relocation and yes the speedometer cable is long enough. I used the Dodge shifter linkages and the frame pivot bracket. It was modified and welded to the LH spring hanger as per the picture. I was able to rubber mount the Dodge intercooler in the front rad cradle. The lh Intercooler pipe had to be sectioned and rotated for alignment. Due to the massive air requirements I opted to stick with the factory filter box. It is mounted where the Jeep battery tray once was. A larger cold air inlet was cut into the rad support at the OEM location. I did not want to run 6 miles of battery cable to relocate the battery,plus it gets cold here in the winter and I wanted the battery close to the starter. A custom battery box was sunk into the rh fender where the old heater box was. To heat the cabin I used an underdash heater box from a mid to late 70's Ford pickup. I had to make some custom brackets but it will fit. The Dodge heater valve was used to control coolant flow. The exhaust is the Dodge donors system with the intermediate pipe removed and a short section added in after the turbo downpipe. The tailpipe had to be sectioned and shortened to exit correctly. I am currently not running a fan but will be adding an XJ fan to create some airflow, but it has not yet climbed anywhere near getting hot. I Used all of the sensors off of the Jeep 360 to retain the Factory look. The Oil pressure gauge spikes when the oil is cold 85 + PSI!! at temp it drops down to normal range. The high output Dodge alternator also makes the amp gauge climb at startup but settles down to operating position quickly. For '91 Dodge used the ECM to control the voltage regulation so a Dodge external Reg. will be required from an earlier truck. Hope this helps somebody. I have over 60 man hours in this swap so it's not a weekend job.

[rustywagoneers_com]

hats off, man,
hope i can be rattling along in a 5.9 (or even 3.9) j-truck or waggy someday soon...
prolly just be a 6.2 though.... but who knows...

peace
Dvae

[pb]

Wow, looks good.

[jeepmj_tj]

hey willysdriver,

check your PM's

[outofcontrol]

awesome project

I have read this post about 10 times, and looked at the pictures at length. I'm glad to see someone besides the crazy Germans trying this transplant.
I have a general question: is the engine bay of the this chief the same as a grand wagoneer?

thanks for the pics!

-Kevin

[The PIG Smith]

Did you have to beef up the frame to support your 6BT?
Could you provide some more details of the Engine mounts?

It appears you are using the stock HD44 front axle.
Do you think this will be strong enough for a 6BT?
Have you considered a Dana60 front axle to support the weight?

Is there any room left for an Intercooler should you choose to add one later?

What kind of fuel mileage you think you will get?
Better than 20MPG?

What is the HP/Torque output of your stock 12v 6BT?

[outofcontrol]

Is there any room left for an Intercooler should you choose to add one later?

TPS- if you look at photo 13 you can see just a little of the charged air cooler between the radiator and grill in the bottom left corner. He also put up a couple pictures of the mounting detail through the grill from the front. (I had the same question first time I saw the pictures)

What is the HP/Torque output of your stock 12v 6BT?

If this motor is in stock form, it should have about 160hp / 400 ft lb

http://dodgeram.org/tech/dsl/Facts/92specs.html

-Kevin

[The PIG Smith]

TPS- if you look at photo 13 you can see just a little of the charged air cooler between the radiator and grill in the bottom left corner. He also put up a couple pictures of the mounting detail through the grill from the front. (I had the same question first time I saw the pictures)



-Kevin

Thank You.
I see that now.

[The PIG Smith]

If this motor is in stock form, it should have about 160hp / 400 ft lb

http://dodgeram.org/tech/dsl/Facts/92specs.html

-Kevin

Oh my! I would figured that a 6BT would be stronger.
I just really did not know.

My brother has a 4BT in a '97 Ford F-150.
It has larger injectors and the injector pump has been turned up a bit.
Other than that, it is bone stock. No Intercooler.
It produces 165HP and 400 ft/lbs of torque on a chassis dyno.
They are other mods he has in mind, like an intercooler and a different injector pump that get his 4BT up to 200HP.
I think in stock, his 4BT produces 120HP. I dunno the stock torque rating.