eggman918 wrote:First off thank's for the spread sheet offer,I've been using "grimjeeper" and so far so good. what power levels are you looking for from your 4BT? I am running the HE221 in my 1968 F-250 CrewCab 4x4 it's a 8,000Lb truck before we start loading it for a trip and the 4BT moves it along smartly at that weight and it pulls our 4,000Lb trailer with ease as well,I would think you will be happy with the 221 and should be able to forgo the c added complexity and clutter of compounds.I am running a VE pump with stock fuel pin and 3,200 rpm spring with the full power screw in 2 turns from the factory 105HP position and a inter cooler from a early '90 F-800 with a 6BT.I see 20 psi by 1,500 rpm under load with a max boost of 28 psi and never see EGT's above 1,200* pre-turbo it also smokes less than most common rail diesels I see on the road I haven't dynoed it yet but my turbo engineer friend told me that if it is making 25psi@2,500rpm it's in the neighborhood of 185hp/425tq and I think that is fairly accurate as the 4BT is out preforming the custom built 390-4V it replaced in every respect and getting double the mileage doing it.The correct turbo and gearing are the two most important variables in the overall drive-ability and user happiness with a diesel conversion.
This is my 4BT powered rig to give you an idea of what those 'little" 4 bangers will move around.
Nice. What kind of MPG are you getting?
I think my gear calcs came from Grim Jeeper originally, or Jedi Jeeper, I don't remember. My wind resistance, rolling resistance, and incline came from all over the place.
I am hoping to get about 250 HP at the crank @ 1500 feet above sea level out of the 4bt. If I am over 225, I think I am good. I want it to be able to hold 75 on a 7% incline at altitude with a bit to spare. I will be operating in high desert at 5800 feet on trips, so a little bit of reserve power is good.
It is good to hear that turbo works well for you. I hope it works good for me as well, especially at the higher altitude and off-road. It will have an inner-cooler, some pump work on the p-pump, advanced timing, valve springs and a higher governor spring. That is about it. I don't intend to flog it or take it to crazy power levels, but I want to be able to push the pedal down and make it sprint on occasion as well as tow a small expedition style camping trailer. I went with the small turbo as I definitely don't want a smoke spewing dyno queen.
I will be running 37's (probably 37.2) with 4.10 gears and will probably be pushing 6,000+ pounds with the fat axles and the boxed frame and roll cage, unfortunately. With the zf-5 those figures will put me at 1830 RPM at 65 and 2111 at 75, and that looks pretty good to me for how I will actually drive it.