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Help me dream up a 4BT

6K views 10 replies 7 participants last post by  curtis73 
#1 · (Edited)
First of all, this is not an urgent issue, nor will it necessarily be a reality, but I wanted to dream a bit on building a nice 300-ish hp 4BT. I live in a smog area, so the chances of legally swapping a diesel into a gas truck is slim, but let's have fun.

I just bought a 98 F150 4x4 and I'm a bit disappointed that I couldn't scrape up the money for a decent 6BT dodge, so I thought... why not dream a bit?

Let's pretend like we're building a 300 hp 4BT for my truck. That should put me around 500 lb-ft which I think is within the capacity of the stock axles (9.75" rear/8.8" front) and a beefed up auto tranny especially considering that traction will be the limiting factor. Can I get there with pump adjustment, injectors, and upgrading a turbo, or will it be more in-depth pump work? What turbo might you pick? Intercooled of course, and at this mild power level I see no need for nitrous or propane so let's avoid it. Don't think hotrod, this is for the utility of a diesel; towing 7000 lbs, daily driver use, and the MPG benefits of diesel.
 
#2 ·
#4 ·
However i think you could probably throw together a 6BT VE or P7100 swap for the same price if you hit the right junk yard.
Quite true, but the mods to the radiator, suspension, firewall, and possibly hood aren't worth it to me to go 5.9. A 3.9 should give me all I need without the excess headaches.

I'll check out that forum you suggested.
 
#6 ·
Sounds like a good starting point. One of the issues I discovered is that it uses an air/water intercooler which (with a steady supply of cool sea water) has an efficiency of well over 100%. I won't be able to duplicate that in a vehicle.

But if I can get enough intercooler and crank it up that's alot closer than starting with a 125hp version out of a delivery truck.
 
#7 ·
I would gamble that a VE pump would be capable of producing as much power on a 4 cylinder as it would be on a 6 cylinder; not as much as a P-pump, but it wouldn't be nearly as limited as the same pump on a first gen Dodge. I wouldn't hesitate to choose a VE 4BT for the 300-400 HP range.
 
#8 ·
Ok, so let's get deeper into it.

Turbo? Will I be at a pressure that might require ringing the deck, or will it be something I should consider doing for reliability?

Assuming either VE or P pump, will it be easy to do turning screws on a stock pump, or am I into some internal mods?
 
#11 ·
Read the original post... this is a hypothetical build. No wallets were injured in the fabrication of this post.

And a 6BT might be cheaper to build, but until you factor in the completely modified front suspension, hammered firewall, relocated radiator, ditching the IFS for a solid axle (or heavily modifying the pan on the 6BT), a stouter rear axle, a completely re-engineered transmission and transfer case, custom driveshafts, and all the other goodies associated with putting a 1200-lb engine in a 1/2 ton truck, the 6BT doesn't sound so cheap anymore.

6BT is way overkill in weight, size, torque, and length. 4BT would be a great match for a 1/2 ton truck.
 
#10 ·
I would really like to put a 4bt in my 85 Cj-7 Jeep
 
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