Cummins 6bt Conversion

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

maxamillion2345

maxamillion2345

Franken-80
10 Year
Joined
Jan 16, 2012
Threads
40
Messages
2,612
Location
Elko, NV
So I started on my build some time ago. Wanted something streetable but an off road toy at heart. Needed to be diesel, have lots of room, lots of power, lots of flex, bla bla bla... enter 92 FJ80 and 1st gen cummins.

Soon after I started, Jonesey's off road, jonesy's auto club, Duiser off road, whatever they're calling themselves started on their 6bt Predator conversion as they called it. As a diesel mechanic and cummins and land cruiser enthusiast myself I was interested to see where they were going with this. As I progressed on mine, they quickly outpaced me.

However, right off that bat, any skepticism was shot down harshly and rudely. I was pretty skeptic of a few things and I also noticed quite an attitude and an aloofness about things. I was put in my place in short order and I sat back to see if my doubts had any merit...

Then they decided there would no longer be a kit, anyone asking why, was shot down harshly, nary an answer was given. Then they became Duiser.

Fast forward... one of our members, infinitely more knowledgable than myself, completes his conversion. It's awesome btw... His friend then buys the LX that Duiser swapped. Problems ensue. What should have been a turnkey operation is shown and proved to be a botched swap full of issues, by two very adept individuals.

I post about it in Jonesy's original thread and POOF the thread disappears. SHADY VERY SHADY.

So with that said, here is my swap. In no way am I a shop, or could I ever pretend to offer a turn key operation... but it's good enough for me. There are some things that could have been done better but funds have been tapering off and I've done the best I can. Anyhow yeah... almost done.

91.5 intercooled VE 5.9
Lucas 300 PODs
Stock H1C
Air to water intercooler
Getrag
NP205
Dana 60/14 bolt
40s/beadlocks
Relentless Fab front bumper
2.5 resi profenders
profender air bumps
3 link front
chevy 63s rear
modified WJ gas tank
hydro assist
dual batteries
all new brake lines?
???

ECF78B05-4481-43E3-AC2D-162E65715DFA_zpscymbrcfb.jpg


DDE0BCB7-6587-486E-8B86-9E17E5E84731_zpskh0bhs9j.jpg
 
I'm considering swapping out my diffs also but run the 47re and a retubed hp60 and d70u. Or may just fork out the 5k on the kit.... I'm on the fence!!
 
OGBeno said:
That is a monster man. Mad Max!! :)


What gearing in the diffs? Total crawl ratio when completed?
Click to expand...
Thanks!

4.56s. Couldn't go too low in the diffs or with the cummins and getrag it tops out too soon. 4.56s with 40s and OD is just right on the highway or at least the math adds up.

I forgot to add I added a gov spring kit and a fuel pin so I can get a few extra RPMs out of it and a little more fuel.

5.53:1 1st gear, 1.96:1 4wd low, 4.56:1 diffs

49:1 on 40s, not great but hopefully I can get a magnum box in the future. Lots of tradeoffs... Lots of money haha.
 
RockJock82 said:
I'm considering swapping out my diffs also but run the 47re and a retubed hp60 and d70u. Or may just fork out the 5k on the kit.... I'm on the fence!!
Click to expand...

The retubed 60 is the way to go if you have the cash. More wiggle room on drivelines and on caster, and keep it up out of the rocks.
 
Mr Cimarron said:
What's your plan to get that beast out of the garage?
Click to expand...

Probably suck down the suspension with straps and either use rollers or air down my 40s. We will see haha.

Jonny D said:
Awesome rig. I will be interested in your mileage per gal when it's up and running. by the way, those are some beautiful welds on that axle truss.
Click to expand...

Thanks, mileage will be interesting but was never really something I uhh built around haha. Thank you, my welding is very hit or miss haha. I lay some awesome beads in some positions and others I wonder who let me have a welder.

OGBeno said:
Diesel.

:lol:

By the way, the lines of the front bumper are pretty impressive. It looks significantly beefier than any off-the-shelf option currently.

No bling either--like a lot.
Click to expand...

Thanks Beno. Eric at Relentless actually cut it out for me and then I welded it all up and he helped me out on the tube work. He does AWESOME work. I'm going to see what he might charge for a rear bumper, as he's like a bumper magician. Unfortunately I forgot to account for the fact that I pulled off the flares and body lifted 2" so it might look a little funny all said and done but it happens haha.
 
Learned a few things in fixing the swap done by Dusier on my 80... More to come later I'm sure

  • When selecting your 4/6 BT motor, look for .004-.014 of end play in the crank.
  • The blind holes in the BT crank are about 20mm deep. Take care to select the right bolt length to fix the FW to the crank. Should be 8 M12x1.25x45mm bolts for the FW if using the Diesel Adapters FW and flexplate
  • The 3800 RPM governor spring is a number 374 and the 3200 is 366 for VE pump BTs. They both google well. The 374 is nice since it won't start defueling too early for highway speeds (3000 RPM or so). Just take care not to actually rev the engine that high as the stock valves springs are reported to allow float at 3800...
  • Don't use soft fuel line for the tranny cooler lines if you're running an auto. Get some real Push lock hose from Russell, Aeromotive, Earl's etc.
  • NPT fittings are an abomination. Don't stack them, don't use them unless you have to. Convert to AN or flare fittings when possible.
  • Use cushioned metal clamps with an eyelet to firmly secure hose and wires to frame/body/engine parts that don't move rather than ty-wraps (zip ties). When you do use ty-wraps get the ones with the steel tab rather than the plastic tab. The quality is 10X better. You'll be happy you spent 7 cents per tie rather than .7 cents per tie when your rig doesn't die in the middle of a bad spot from a critical tie breaking--- also back to avoid using ty-wraps for critical stuff;)
  • The 6BT oil pan likely needs to be notched to clear the connecting link, front drive shaft yoke, and the tube cross member. Not hard work, really.
  • The compushift controller for the A334F trans can give you OEM like driving. Worth it.

Phil
 
Tell me more about this soft line on the tranny cooler... I'm using the stock tranny on the return side of my power steering. Just running normal petroleum rated hose.

FWIW I went with the 366 spring on mine as I'm not ready to swap valve springs yet.
Put in a new fuel control lever bushing, oring, and pump top gasket at the same time.
 
My business is building race cars, so I've learned to be a bit anal about hose and fittinsg. As a general rule, standard SAE J30R3 is typically what I find people use to transfer fluid in home swaps. The stuff is junk. The J30R9 isn't a whole lot better. Is good practice to just jump on Jeg's website and buy real pushlock hose and fittings. Even if Jegs branded (which is Russell I believe), it's going to be better than what the OE used and especially better than what you can find at the parts store (SAE J30 spec). Also it's time to replace 20 year old hoses anyway :). While on the jegs website, grab the needed pushlock fittings. You can convert from NPT to AN in almost all cases. That pushlock hose is so tough that you'll need a heat gun and oil to get the fitting pushed into the hose. To that end, you'll build the hose on the bench. Put the fitting in your vise (use some aluminum on your jaws to protect the fitting), heat the hose to where it's too hot to hold (use gloves of course), squirts some LP-1 on the fitting and install the hose to the fitting.

Not only will your truck look better, but you'll never be left dead for a hose bursting.

Just to be clear, pushlock hose is not that fancy steel braided stuff that's super hard to work with. Pushlock looks like normal rubber hose, but it's super tough and economical-- It's rated to 250PSI and it's chemical resistant both internally and externally, so that leaky oil pan won't cause your pushlock hose to degrade like the parts store stuff...

For those that don't know, AN sizing is EASY. the number is always X/16. So -4 is 1/4" (called dash 4 and so on), -5 is 5/16, -6 is 3/8", -8 is 1/2", -10 is 5/8", etc....

Hope that helps,

Phil
 
Thanks Phil. I'm very familiar with pushlock fittings as well as JIC and other hydraulic fittings, I even made the hydraulic lines to my hydro assist ram -6 JIC. I've not really had any issues using standard fuel hose though either. I have a mix of stuff on mine with goodyear 3/8 fuel hose to and from the tank and as well as on the low pressure side of my power steering. I agree though, the pushloc hose and fittings would be the way to go if I had the funds. I'm sure I'll end up replacing the two short runs of hose on the return side of the power steering as they will get soft over time. I probably should just go get some hose from delta rubber I guess.
 
Just to add another tip. As mentioned before, gotta clearance the pan for the OE connecting link or it will hit. Hit the pan is a bad deal for many reason obviously. One of the biggest is that the oil-pickup is directly above the connecting link. So the pickup needs to be bent out of the way and/or extended in addition to the pan being notched.

You'll need to apply a "speed dent" above the panhard bar support/cross member so the motor can rock without hitting it. More pics of the modifications to come later.

-Phil
Stock Pick-up Location

Stock Pick-up Location

  • Media owner turbophil
  • Date added
This will get moved in the 6BT swap
Pickup hitting pan

Pickup hitting pan

  • Media owner turbophil
  • Date added
Connecting link hit the pan causing the pick-up to contact the pan and block a good portion of...
 
You must log in or register to reply here.

Share this page

Back
Top Bottom