Cummins 4BT '68 F-250 4x4 swap

[eggman918]

Well let me start at the beginning ,after killing my 390 I decided to go diesel for reliability and mileage.
After input from averageF250 I decided on the Cummins 4BT turbo diesel it is a short motor but tall
it will fit the engine compartment nicely.I found a '88 GM chassis step van with the 4BT and a B/W T-19 4 speed.
The van cost me $2,800 I recovered $1,000 in scrap metal plus 6 tires&rims with %75 tread @ $200.00 and a
GM 14 bolt rear end @$200.00,so I am in $1,400.I drove the van home 350 miles @ 65mph and got 18mpg.
My plan is to install a Ranger splitter %.27 od to the T-19 and run 3.55 gears,than is more complicated than
other setups but I spend lots of time offroad and in the mountains on old logging roads so more gears equals
more time with motor in the happy spot.The 4BT has a reputation for both power and reliability,It started
at 105hp@2,500rpm dont know the FT/LB's I have been told that 200hp and 400FT/LB is easy to get
and still retain the reliability.I do not think that I will need that much motor but it is good to that the potential
is there.I have motor in truck and aligned with transfer case the T-19 bolted to the NP-435 mount .
It seemed that it was meant to be in this platform all along .I have started a photo page for this project.
this is the link I will update this link as I make progress
http://s1042.photobucket.com/albums/b429/eggman918/

[1971ford]

Nice! I want to do the same swap in the highboy. Some day...

[FreakysFords]

Lookin good!

Gotta love a diesel! I work on them every day and even I will admit to the 4bt being one heck of a tough little engine (from a man who is NOT a Cummins fan).
Hoping to do a similar swap pretty soon myself (on the 350).

Frank

[hazelnut]

Sounds like a good idea putting a 4BT in you truck, you mileage will probaly double from what the 390 was getting.I wonder if a 4BT would fit in a newer ford ranger.

[averagef250]

Glad to hear things are moving forward. I use my trucks hard, as a truck should be used, take care of them and try to make them user friendly and versatile. I spend a lot of time towing heavy trailers and on unmaintained logging roads in the summer time, one spot I go to (the spot in my avatar pic) is an unmaintained grade that goes up 4000 feet in 4 miles. In my own eyes, having a 5 speed with a 2 speed transfer case gives me 10 very effective forward gears to cover all manner of road speeds from almost zero through 90 MPH. It's also very easy to use and maintain. On the same turn a ranger OD in front of a close ratio T-19 with a 2 speed transfercase gives you 16 forward gears to choose from. Not to be a debbie downer, but 8 of those 16 speeds suck, none of the splits are very even and ranger OD's are not a great marvel of modern engineering. They're pretty failure prone, shift badly and are extremely awkward to drive (especially if your lucky enough to have an electric or air shift version).

You would have far more effective splits if you kept your 435 instead of the T-19 with the 4BT, BUT then you absolutely must split 2/3 gears in normal driving. Something you'll really hate after a couple hours in traffic.

You can mess around with all that silly ranger stuff and gain an extra difficult to use shifter or smoke prone electric shift motor or you can just save yourself a couple thousand dollars and get a nice shifting affordable late model ford 5 speed and easily make it fit the cummins and the truck.

If you want 10 gears get a roadranger and bolt it to your 4BT. A 10 speed roadranger will actually cost less than a ranger OD.

[eggman918]

Dustin you have a point I already have the T-case set up as a twin stick for the mountains,so again I am over thinking this.
As I dont have money to burn only time in abundance your counsel is sound.So now I am back where I was in the beginning
thinking ZF 5 speed.How heavy is a roadranger,in bakersfield it might be easier/cheeper to find are they huge.
Today I was to fab motor mounts,but if.........will a small block ZF bolt to my adaptor and if so I need to wait on mounts.
If that is the case then I will do the hydroboost and clutch master cyl. today
What other medium duty truck 5 speeds fit the T-19 bellhousing?

[averagef250]

The only single solitary transmission I would suggest using with that adapter is the M5R2. If you want the ZF save yourself a whole tone of hassle and put 3.08 gears under your truck with the T19.

The small roadrangers weigh 1/2 what your engine does.

The point most people are shooting for with a 4BT is enough power to do the job well and economy. A ranger/t19, ranger/435 or roadranger don't do any of that. The small block gas ZF is a wide ratio 5 speed. Use it if you like, but before you buy one I'd suggest just hooking up your 4BT to 435 and driving it. That's going to be the same thing you get with the gas ZF but without overdrive.

You're not settling by not having 42 different gears to choose from. If you really, really like shifting go for it, but a bigger transmission is more parasitic loss, a ranger OD is a huge parasitic loss, a ZF has bad ratios and is bigger than necessary, the M5R2 is "just right". Not to mention they're as common as bellybuttons and will cost you around $150 for a good one.

[eggman918]

Started motor mounts ,I will go as far as I can.However now I am rethinking transmissions,that is a big decision and a weak spot in my knowledge.
Getting motor and trans in and aligned is the easy part for me.All the "little" things will be what has me pulling out me hair.
New pics.
http://s1042.photobucket.com/albums/b429/eggman918/

[eggman918]

I just returned from a "gear calc." page,my only concern is the strength of the m5r2.Now and then I am real rough on the truck
and usually far from the pavement.Crunching the numbers the m5 looks good but ? I like the simplicity of the install,
but if it shouldn't break without trying to break/flog it I will give it a try.My damn truck is already "over weight" due to my "over building it.
What is the overall length of M5R2? And it is a slip yoke output shaft right.
Thanks for talking me off the ledge

[averagef250]

I don't have a 2wd one to measure. 4x4 is 27.5" from bell face to tail face. I've been over 20K with the M5R2 and 4BT several times. I've put 450 lb/ft through every gear in that tranny with 3rd, 4th and 5th holding that load for atleast 5 minutes continuous, more like 30 minutes continuous in 5th gear.

Like I said again and again the limiting factor is your CLUTCH with the small block Ford adapter you have. An 11" clutch disc is all you've got, the M5R2 will take anything you can put through that clutch. For what you're doing you will be real happy with the M5R2. If you you went to massive injectors, twins and some sort of custom twin disc clutch to put that power to the tranny you'd probably snap the input shaft off before anything in the tranny broke. Not to mention you won't be towing a darn thing with a 4BT making more than 300HP. it won't stay cool enough.

[eggman918]

I have started the hunt for a M5R2,and have the block side of motor mounts finished.I will wait on the isolator side after I get transmission.
Today I will mount the hydroboost and master cylinder,and start to get fire wall cleaned and wiring in order.
new pic's tomorrow.

[eggman918]

Motor mounts are finished,next is fire wall and under dash.
new pic's
http://s1042.photobucket.com/albums/b429/eggman918/

[eggman918]

Well the hydroboost is mounted as is the clutch master cyl. things have slowed down a bit, the weather has been bad so I have been the shop.
Made a new fan mount for the water pump pulley, lathe work some good pics http://s1042.photobucket.com/albums/b42 ... er%20pump/
Next is a cable tack drive,that should be FUN
new pics for swap....http://s1042.photobucket.com/albums/b429/eggman918/

[eggman918]

Found a M5R2 trans. at pick ur part $178.00,today I will clean and inspect trans.
Tomorrow I will start shopping for overhaul kit..

[Fordnatic]

Nice work!!