The official 6bt conversion thread

[mljjones67]

Dustin will this work and be worth it??
http://cgi.ebay.com/ebaymotors/Cummins- ... dZViewItem

[mljjones67]

Here is a conversion for the zf 2wd
http://home.austin.rr.com/broncenstein/ ... 20swap.htm

[nevrenufhp]

Dustin will this work and be worth it??
http://cgi.ebay.com/ebaymotors/Cummins- ... dZViewItem

It would be great, if you could fit it all under the hood. Another method for those, is to have a chilled water tank in the bed, and run a separate pump to run into the intercooler...if that makes any sense.
Usually, they are plumbed thru the cool side of the cooling system.

[mljjones67]

Here is a list of all the threads od interest at 4btswaps
http://www.4btswaps.com/forum/showthread.php?t=1076

[Zeke71250]

More questions. I know there aren't any guarantees - so educated guesses will do nicely.

1. Is it unreasonable (in trucks like ours) to expect a 4BT to pull respectable 0-60 times? By respectable, I'm thinking 11 seconds or less... unloaded.

2. What exhaust diameter is a good one to use?

3. Is any muffler good enough? Or is one design (straight thru, chambered, stepped) better than the other? Is a muffler even needed?

4. Assuming a 5" lift, taller-than-stock tires (maybe 33's or 34's), and one of the ZF 5-speeds - Will 3.73 gears be tall enough to get moving? Or would some other ratio be better. (Mine's a 2WD if that makes a difference)

5. What's a reasonable hp/torque figure to expect if your only mods are upgraded air flow (in and exhaust) plus whatever minor adjustments can be made to the engine? And what can be expected with the addition of the turbo?

6. Is an aftercooler necessary with a turbo? Or is it just adding a little "more" to the mix?

7. Once installed, is there still enough room to get an A/C compressor bolted on?

I'll have more as I think of them - thanks for all your time and patience.

[Zeke71250]

I try to run the first generation dodge 5.9 saginaw pump, I've been lucky and found them with the extra return for hydroboost. These pumps can be upwards of $150 on ebay and sometimes very hard to find. You can usually find several combination PS and vacuum pumps for sale on ebay, but these are almost always $200++ and they are very expensive to rebuild when they go out. I figure the point of the diesel is simplicity so I stick with the standard, proven saginaw pump and convert to hydroboost power brakes.

This Saginaw pump of which you speak - am I correct in thinking that these can be found on just about any Dodge/Cummins truck? Or are they strictly like '98 and older?

Also, what else is involved in the conversion to hydroboost brakes? I take it that'll also mean our existing power brake assembly has to be trashed and replaced with a Dodge unit?

[Zeke71250]

Questions on the labeled pic below.

A - What the heck is THAT critter?

B and C - What are these reservoirs?

D - Where's the booster?

[heep70]

Let me try my luck.

A- I would think it is the air cleaner.

B-

C- PS pump.

D- it is hydrolic and doesn't need a booster.

[nevrenufhp]

A- the air filter/ air cleaner assy.

B- oil filler going into the timing case, or so it seems by the pointer.

C- PS pump

D- that IS the booster, hydroboost, that is.

[averagef250]

Yep, the 12CM turbine housing will make upwards of 25 PSI boost for a safe 150 horse or better without an aftercooler. With an aftercooler the same pressure is actually pushing a lot more air through the engine so the same turbo can make more power or use less fuel to make the same power.

The 12CM WH1C turbine housing can easily be found on ebay for under $100 shipped to your door.

[Zeke71250]

Yep, the 12CM turbine housing will make upwards of 25 PSI boost for a safe 150 horse or better without an aftercooler. With an aftercooler the same pressure is actually pushing a lot more air through the engine so the same turbo can make more power or use less fuel to make the same power.

The 12CM WH1C turbine housing can easily be found on ebay for under $100 shipped to your door.

I'm looking for the downside to all of this, and I ain't seeing one.

[nevrenufhp]

Those are variable vane turbos, but still a '35. I think 04.5 & newer went with this...not 100% sure. You'd have to find a way of actuating the variable vanes with a computer, or set it in a fixed spot.

[LincTex]

What is the official Cummins or Bosch part number for the "366" 3200 RPM governor spring?

I'll need to know what to ask for, and I'll have to have a good number when I do.

[LincTex]

If there's anything else you guys want to see let me know.

I would like to see how some guys handled clutch linkage duties.
I still haven't decided how to mount the engine-side "ball stud" for the clutch Z bar.

[briney]

have any of you guys seen a direct drive starter for the 4bt ? my reduction one hits the steering box.