1948 B-1-PW 4bt swap

[carisu]

I'm beginning to research my options on the restoration of my grandpa's 1948 B-1-PW.

I have restored 7 antique tractors but this will be my first automobile.

I would love to have a road worthy, diesel powered, machine with upgraded suspension, brakes, and axles but I have decided that I just don't have the budget for that right now.

What I would like to consider is leaving everything stock except swapping the 230 flat head with a 4bt cummins - if that is even possible. I would sacrifice the road speed but would still have the power, reliability, fuel efficiency, and pure awesomeness of the 4bt.

I see a lot of people doing this swap in similar dodge trucks but I have yet to find out whether or not it will work in my specific truck? I have no problem doing fab work as that is what I do for a living.

What I'm looking for is exactly what motor would I need and exactly what adapter plate, etc I would need to mate it to the PW's transmission and transfer case.

Any help would be greatly appreciated!

[Gordon Maney]

I think you are going to find that no one will recommend you stay with the original transmission, partly because of that transmission and also partly because of the bellhousing requirement. More will be along later to comment.

[Desoto61]

A search here will turn up some options, but I'm not sure it's even possible to use the stock tranny without some crazy custom adapter.

You can definitely find a 4-speed if you want it but there are a few five-speeds that will fit in front of the stock transfer case too. And honestly if you're not upgrading the transmission or differentials for different gearing I'm not sure what the point behind the engine swap would be. The gearing is one of the main things preventing higher road speeds, and a Cummins isn't going to spin any faster than the 6 does. And for reliability and longevity the flat-head is no slouch. It would be far quieter and smoother too.

The extra torque of the 4BT is what allows you to use OD and the lower axle ratio to get better top speed. With just OD you'll at least still get some of the speed benefit. A set of larger tires will also help your road speeds too.

The early 2WD Chevy NV-4500 I'm using will fit but is probably the most expensive route due to the rarity of the trans and the rarity and cost of the flywheel.

The Spicer that Charles uses will fit but the parts needed to mate it to the Cummins can also be tricky to figure out/find.

Probably your best bet would be to try the Ford setup, the adapters aren't cheap but they're not too uncommon, the parts aren't as expensive or rare as the Chevy setup, and the transmission is much more common. Only tricky part is making sure to get the right tranny. There were a few different models and versions over the years.

Finding a decent 4BT however is getting very tricky. Prices have gone crazy for them from most of the usual sources, and that's for well used ones. The ones with water aftercoolers are easier to install and make more power than the non aftercooled engines, but don't seem to be as common as the air-to-air aftercooled versions. Then you either have to convert them or fab up some way to fit the air-to-air intercooler, which as far as I can figure isn't going to happen with a factory radiator, or without a very custom cooler. Which honestly would probably be equally expensive.

Just be careful, you may not want to do the brake upgrade yet but you'll need good brakes to stop that truck from higher speeds and I'd look carefully at the cost of rebuilding the stock drums vs the disk conversion if you went that route.

Good luck!

[bobyepsr]

Carisue, I'm planning the Cummins 4bta, Ford 5spd ZF transmission, Chelsea 352 pto (to run the winch) and Dana axles (44 front and 60 rear). I've collected all these parts and plan to start by sand blasting and painting the frame after the Iowa rally. I haven't done anything about changing the transfer case. I'm planning to drive the centered axle from the e-brake shaft. The motor has a hydraulic pump for the power steering that I plan to tap into for a dump bed. I've been planning this for a while so I have picked up the components here and there. EBay,craigslist and a local bread company(I bought three cummins trucks from them).So far I haven't put any of this together. Just finished a job working for 6 weeks straight 12 hours a day 7 days a week. Right now I'm playing catch up on the lawn and landscape. June is labeled start the power wagon project on my calender. This site has a ton of info and great people to learn from. I have an extra 4bta with the Ford adapter for sale but I'm in Ohio so you can probably find something closer. Jim

[Desoto61]

Carisue, I'm planning the Cummins 4bta, Ford 5spd ZF transmission, Chelsea 352 pto (to run the winch) and Dana axles (44 front and 60 rear).

Might consider using a PTO setup running a hydraulic pump. You would have better capacity for the dump bed and you could convert the winch to run off a hydraulic motor, which gives you more flexibility there too. There would just be the added hydraulic system to deal with.

[Gordon Maney]

Carisue, I'm planning the Cummins 4bta, Ford 5spd ZF transmission, Chelsea 352 pto (to run the winch) and Dana axles (44 front and 60 rear). I've collected all these parts and plan to start by sand blasting and painting the frame after the Iowa rally. I haven't done anything about changing the transfer case. I'm planning to drive the centered axle from the e-brake shaft. The motor has a hydraulic pump for the power steering that I plan to tap into for a dump bed. I've been planning this for a while so I have picked up the components here and there. EBay,craigslist and a local bread company(I bought three cummins trucks from them).So far I haven't put any of this together. Just finished a job working for 6 weeks straight 12 hours a day 7 days a week. Right now I'm playing catch up on the lawn and landscape. June is labeled start the power wagon project on my calender. This site has a ton of info and great people to learn from. I have an extra 4bta with the Ford adapter for sale but I'm in Ohio so you can probably find something closer. Jim

Please take lots of photos and write an article or several for the magazine!

[carisu]

Carisue, I'm planning the Cummins 4bta, Ford 5spd ZF transmission, Chelsea 352 pto (to run the winch) and Dana axles (44 front and 60 rear). I've collected all these parts and plan to start by sand blasting and painting the frame after the Iowa rally. I haven't done anything about changing the transfer case. I'm planning to drive the centered axle from the e-brake shaft. The motor has a hydraulic pump for the power steering that I plan to tap into for a dump bed. I've been planning this for a while so I have picked up the components here and there. EBay,craigslist and a local bread company(I bought three cummins trucks from them).So far I haven't put any of this together. Just finished a job working for 6 weeks straight 12 hours a day 7 days a week. Right now I'm playing catch up on the lawn and landscape. June is labeled start the power wagon project on my calender. This site has a ton of info and great people to learn from. I have an extra 4bta with the Ford adapter for sale but I'm in Ohio so you can probably find something closer. Jim

Jim, what truck do you have that you are planning to do this swap in?

I always have the option of just restoring the truck to original condition with the original motor and drivetrain. I just like concept of putting a cummins in an old power wagon and I like the way the diesel sounds (Listen to this thing!). If it's not possible to just swap the engine I may go that route. I don't want to pour a bunch more money into this to get it road worthy. I can be happy with an "off road vehicle"

Not that I would probably wear out either motor in my lifetime with the amount of driving that I'll do with it but there's no way the flathead with the valves in the block has the reliability of the cummins.

[bobyepsr]

Carisu, I have a 1951 body that I plant to put on a 1948 frame. I have parts of 4 trucks here but most of the sheet metal and frames are way past useful. I seem to be rich in running gear, the parts I'm not using on this truck. But like others who have been hooked, I see an all original project some day. For now it's pick the best fenders and doors to rebuild. The best cowl lights. I hope to come home from Iowa with a headlight and lots of up close pictures of hanging peddles, motor mounts and such. I've been plotting this for a long long time. I bought my first truck in the late 80's. For now the only thing I'll use from it is the winch. Some time in the future (that stock project) I'll use the crash box and pto with front and rear output shafts, and if I'm lucky those smaller wheels will lead me to a usable set of highway gears.
At this point I have spent more money on the running gear and replacement parts than I did on the trucks. I'm OK with that as my goal is a driver that I can load up and head into the woods for fire wood or to Iowa on the freeway. Jim

[carisu]

Thanks for your input. I'm going to try and make it over to the rally this year to get some ideas as well. I'm pretty new to power wagons but I'm learning slowly!

[carisu]

Man! I keep going back and forth! In some ways, if I'm going to put the time into the restoration, I might as well make it road worthy. I'm going to have to overhaul everything anyway so why not swap the axles, tranny, and motor and really have something usable when I'm done.

I can say for sure that I know that I would use it wayyyyy more if it was able to travel at least 65 mph and pull a trailer with my latest tractor restoration to a tractor show!

I realize I'm going to have some cost involved in getting all of these parts gathered up but I'm sure to have some cost in getting the replacement parts to restore the original ones too...

I'm sure you guys have heard about Legacy Classic Trucks but their work is truly inspiring!

Especially the video of the PW pulling the Cat!

So Jim,

I assume your setup will maintain front and rear pto and the 4WD capability?

What will be your estimated top road speed?

edit: My name is Austin by the way :)

[bobyepsr]

Austin, The Cummins 4bta--Ford ZF 5spd. transmission--NP200 transfer case--Dana 410 ratio axles-- 37" Humvee tires should give me 55 mph @ 1560 rpms in 5th gear, 60 mph. @1700 rpms in 5th gear and 65mph @ 1844 rpms in 5th gear. (I hope I did this right)
The pto unit is a Chelsea 352 that could be set up to either have its drive point to the front or the rear. I'm using it to run the stock Braden winch. This pto allows the shaft to drive clock wise or counter clock wise so the winch can power in and out. Paul in NY has info on this in one of his builds. (nice guy who has called and offered me info on the phone, His go to guy at Brookline Machine helped me get the correct input gear to match the zf) The winch could be driven with a hydraulic motor using the existing power steering pump on the motor. Paul explained this option to me also, but I found a pto unit so I'm staying mechanical.
I'm no expert on any of this! I've been researching and plotting for a while. To date I'm that rancher with a big hat and no cows. Jim

[carisu]

Thanks Jim I appreciate the help. I have only just begun doing my research. So far, I'm that city guy who drove by the cattle farm and thought to myself, "I can do that!"

[bobyepsr]

4bt swap (transfer case) question

The only part of the running gear on my project I haven't planned to replace is the transfer case. Just to repeat my self I have a 4bta, zf 5 spd. and dana axles. My son feels I should change to a 205 transfer case. I think the 202 with the center output on the brake drum will be just as good. What do you all say. If I change how much of a direct swap is it. Thanks Jim

[carisu]

Correct me if I'm wrong but the 202 and 205 are fundamentally the same but with the 202 you have a dedicated gear to hook the PTO too?

From what I've read, the 202 is built a little heavier but the 205 is significantly smaller and is pretty strong even in stock form.

[Gordon Maney]

The 205 has a single shift lever coming through the floor. The earlier transfer cases have two levers.