I have a 73 F-250 Crew. I am really interested in this engine (Cummins 4BT) but am unsure if it can pull the planned truck around. I have read of 350TQ reasonably. I am not in a race and I like the possible MPG of this motor. Also I like the initial cost vs. the 6BT. Plus it will fit better (I have seen the 6BT these trucks and it looks nice). It will be a manual, 6sp if I can get one. I also will be doing BIO and WVO or SVO.

I do have an 85 6.9 available. Really though... the MPG is not great. In the mean time I may use my current 390. Just to get it usable rather than a lawn orniment.

The planned truck is a Crew Cab with a 10-11 foot utility box, 36inch tires, and 6x6. At this point I have all the parts to make it happen. The finished product might be in the 8-9k range for weight -fuel. The truck will also be used for my rather heavy camper and towing a car trailer.

It will get Town, HWY, and Off-road. It will be used like a truck should be, hard. My recent trip to scrap was over 9k and that was with the truck as is. If the oil burning works out I may commute the 20 minutes in it.

So does anyone know the 4BT and do you think that is will do ok for the application? I am fighting the big power pull a mountain mantality that I am feeling.

There are pics in my gallery of most of the stuff for this swap.

Thanks,

Calvin

 

The Mech at work and I have been rolling around the idea of one of these in a ranger, not nearly as big as what your thinking of doing. just for the pure different factor. and I think ya could get some realy good milage out of it.

I realy dont know any of the hop-up parts for these things but I would bet a small turbo and twist a few screws could really help them in the HP department. ours only revs to 2K but I bet you could spin em alot harder being there so small, a 6BT will go to 4K, dont see why these wouldnt.

sounds fun, I just think its a lil small for 9K @ 60+ MPH. I dont think it could do it.

Diesel Rod

 

Good points, decisions decisions. The hop-up parts for the 4BT are the same as the 6BT. I have seen all kinds of numbers possible. A low of 40hp detuned NA to 250hp aftercooled turbo for marine. As high as 350hp if you really want to push it.

You are right I think 4k to 4500 is possible while staying reliable. It is that mileage that makes me really want this to work. Both the MPG and that they can go forever. I also like the idea that it only needs about 3 wires to run.

I know these could be had in the bread trucks, UPS trucks, frito lay trucks, snap-on tool trucks any one driven one with a good load in it? I would think that my truck will be at least close to a loaded tool truck in weight.

Around here 60 is the limit anyway. What I would not give for a real Interstate.

Thanks,

Calvin

 

I have a 180hp 5.9 in my 79 F250 supercab shortbed 4x4. It was intercooled in the 93Dodge it came out of, but I ran without, slightly better throttle response . I wouldn't even consider a 4BT mainly because of its 3.9litre displacement. It's life expectancy would be severly shortened by using it at maximum power All the time. I have a 72 Bronco that I have been saving for a 3.9 4BT when I can get one at a reasonable price.
I put a 6.9 C6 into an 88 Bronco and got a consistent 20mpg . I don't think a 3.9 will pull a crewcab around unless you use a 10spd direct tranny and really low gears.
One of my buddies has a 7.3 idi in a 79 F350 4x4 and it was a pretty simple install.
Good luck with whatever you decide on.

 

Not to discourage you but, I have drove a bread truck with this engine in it. It was at a lawn and landscape company, the truck was used to hual potted flowers to jobs sites with. Top speed was around 60 and the mildest grade would take it to 45mph quite gutless