cummins 6bta Diesel Wagoneer Project

[FSJeeper]

Down to final decisions before I start pulling the stock drivetrain out of my 91 Wagoneer Project. I have been emailing my diesel guru buds at the various diesel swap pages as well as having a final discussion and debate last weekend with our Texas FSJ diesel authority who pioneered the FSJ GM 6.2/6.5 and 6BT swaps years ago. The 6BT FSJ has been his daily driver ever since then. He recently sold his Cummins M715 which is up north now. I have been very lucky to have been a part in all of the several FSJ diesel swaps that were done in his shop.

Final decision is that I am going with the Cummins 6BT instead of the built GM 6.5 I have. His recomendation was an automatic but I prefer a standard so I am going with a NV4500 and a NP205. The Cummins 6BT I have has only 60K miles on it. I am mildly upgrading the turbo to a HX-35, upgrading the injectors, and modding the injection pump a bit. Should pull 250hp out of it and still get excellent fuel mileage with it. It WILL NOT be intercooled. Don't need it for this specific application based on my experience now with early Dodges.

I bought a 91 Dodge Cummins truck for the donor for this project but am using a different engine I have that is basically new. I have driven this truck a lot now and have a 2004.5 Dodge Cummins truck to compare it to. Yes, the 24 vavle Dodge has more HP, but the 12 valve torque comes on so soon and stays flat at lower rpms. Very driveable. Plus it gets excellent fuel mileage which I can not say for my 24 valve truck. In short, the 12 valve is perfect for my needs in the Wagoneer whos focus will be a daily driver and hopefully a fuel mileage king.

Willie has pre-engineered the swap and all of the details which have been test proven for many miles and years on the road and totally insane offroad thrashing as well as competition tractor pulls. If the Cummins could survive that guy, it will have no issue for me in this project.

I bought another set of the early Dodge Dana 61/71 axles with the 3.07 gearing in them for this. They are exactly like the set I bought for the crewcab.

I know that on very rare occasions I have been known to change my mind, but I think I am settled on this direction. I am open to any other ideas before I start tearing out the stock Jeep drivetrain.

PICS of the project wagoneer:

http://froadin.com/pascal/wag/

[Lindel]

That's a sweet Waggie Pascal.

The main concern that I would have would be beefing the front suspension enough to take the weight of the 6BT.

[etjeep]

Sounds like a sweet project. I agree with Lindel's comment on the weight issue, that would be my concern as well. I guess you have the spacing worked out in the engine bay. Must be very tight. I will be following this build. I would like to build a DD like this some day.

[710 Burner]

Talk, talk, talk. Where's a wrench??

[FSJeeper]

That's a sweet Waggie Pascal.

The main concern that I would have would be beefing the front suspension enough to take the weight of the 6BT.

I am going to start with Willie's recipe cause it worked so well for him for years with zero issues. Willie used STOCK M715 springs with one leaf removed. He bead blasted them, painted them in lubriplate, and put nylon sliders between the leafs. His M715 rode very nicely. If it is too harsh for the wagoneer, I'll take another leaf out or jest get some custom springs made.

[FSJeeper]

Talk, talk, talk. Where's a wrench??

Most people do not plan to fail, they fail to plan. I am in the planning stage.

[N2Jeeps]

FS Jeeper

I obsessed on every part of my project from the drive train down to which flared fittings I would use on the fuel system. You need to plan like this to make it a successful project.

When I finished mine she started the first time I hit the button and has never thrown a code. Proper planning will make all the difference.

That is one clean GW and should make an awesome project!

Tony - N2Jeeps

[will e]

I have to hand it to you, that is a challenge I don't think I could take on. And yeah, you need to have a well thought out plan in place. Sure, it will take a turn now but with something this complicated, a good plan is a must.

[addicted]

You should pull down mid 20's at the very least with those gears and an overdrive. They used those gears behind the 727 auto's and 3:54's in the manuals with the Getrag. I get 20 or better depending on the fuel I can find for my 92' extended cab W250 with an A518 non lock-up auto, 3:54's and an NP205. I used to average 22 mpg before the ULSD was everywhere.
The last time I came back from my parents in S.C. I found a Texaco with B20 and got 22mpg on the freeway running 75mph that kind of speed usually nets me 19 mpg at best with an almost 8000 lb truck.

I do the love the power and growl of the mighty 12V Cummins. Now if only I can stumble upon an NV4500 for cheap, (and when I have the money) I will be able to pick up another mpg or so and get rid of the power robbing inefficient slush box.

[j20brett]

thats one clean waggy there Pascal. but it sure would look better with a razor up front

[COLOFIREMAN]

Very clean Waggy!! I also thought of the 6BT, but the 4BTA that I'm using just seemed to fit alot better. I can center the weight more by moving the motor back and lower in the frame and have room for the intercooler. There are disadvantages to no intercooler but I think your swap is going to be a great daliy driver/wheeler.
GOOD LUCK!!!!!

[FSJeeper]

Very clean Waggy!! I also thought of the 6BT, but the 4BTA that I'm using just seemed to fit alot better. I can center the weight more by moving the motor back and lower in the frame and have room for the intercooler. There are disadvantages to no intercooler but I think your swap is going to be a great daliy driver/wheeler.
GOOD LUCK!!!!!

I was very, very close to choosing a 4BT. To be honest, it was the noise level that pretty much killed that deal for me. Vibration issues were second. For a weekend truck or something like that it would have been perfect, but not for a biz use vehicle. If it would have been quieter though, there would be no doubt I would have gone 4BT. I think I could have probably got close to 30mpg with it. I have followed your swap over at the 4btswaps page, nice job!

I am lucky in that all of the details of the swap have already been figured out and tried and proven over years of use from my Jeep buddy.

[Tanker (MWJT)]

Can you post a link to that 4bt build?

[FSJeeper]

Can you post a link to that 4bt build?

http://4btswaps.com/forum/showthread.php?t=1278

[710 Burner]

Truth be known.....you are probably doing my planning for me.