Cummins 6BT conversion

[Captain23]

I just picked up an 84 FJ with a half complete Cummins 6BT conversion project. The engine is in, all it needs is the drivelines built, tranny and transfer case installed and some interior stuff. Tim up at Landcruiser Specialties in PDX is helping me put her all together. I'll be posting pics of the build.

The tranny is the NV4500 5spd
Transfercase is NP205
This is my first question, can you get an adapter to mate with the toyota axles, or should I go with an adapter to the stock transfercase? I'm worried about the stock holding up against the torque of the beast!

Springs, at the moment were going with SOA to clear the oil pan and, i have 4'' lift springs from man a fre, not sure what brand, they came with the truck, dude was going to run 38's on Dana 60 axles. Also I have some stock springs from another FJ. I was thinking of doing the OME Dakkars, for strength, but I'd like to ride a bit smoother, any ideas?

Gears, I want to run 35's, probably true 35's - the toyo open country MT or the PRocomp XT. What gears to run? 4.11? or 4.56?

Eventually I want to build or buy an SVO system. ANyone done that to one of these?

ANy info would be sweet!

[cody c]

4.56 or maybe 4.88 gears would be ideal for my 3B diesel with 35's, but i dont know what would be best for that motor/tranny. If you had D60's i throw them in to match the drivetrain you have and the power of that cummins. If you keep the stock axels get some longfields first thing. There is also a stronger aftermarket rear axle shaft but i cant remember who sells it.
I think the dakars might give a softer ride with the heavier motor you now have in it. i would suggest trying them out before swapping something else.
Also i would suggest taking the Toyo's over the pro-comps. Especially if you do many highway km's.

[gifu]

search a little on the gearing for a Cummins. You want to be running at about 1800 at 65MPH. This means, you want 35's and 3.73's with NV4500. Not 4.10's, not 4.56's, not 4.88's. These motors do not enjoy being over 2000RPM... redline is 2500 or so. I only wish I could find higher then 4.10's for my 80 series Cummins.

[Captain23]

Originally Posted by gifu

search a little on the gearing for a Cummins. You want to be running at about 1800 at 65MPH. This means, you want 35's and 3.73's with NV4500. Not 4.10's, not 4.56's, not 4.88's. These motors do not enjoy being over 2000RPM... redline is 2500 or so. I only wish I could find higher then 4.10's for my 80 series Cummins.

Cool thanks gifu!
I read that on the cummins 4bt board last night too. That should be what is stock in the toyo axles. Is your's a 6BT? Can you not get 3.73's for an 80?

I'd thought about doing the dana 60 axles, but they're wider, twice as heavy and another 1500 bucks, and they'll take a lot more custom work to fit the brakes and steering.

[prado t]

Originally Posted by gifu

search a little on the gearing for a Cummins. You want to be running at about 1800 at 65MPH. This means, you want 35's and 3.73's with NV4500. Not 4.10's, not 4.56's, not 4.88's. These motors do not enjoy being over 2000RPM... redline is 2500 or so. I only wish I could find higher then 4.10's for my 80 series Cummins.

NO a 6BTA has the mechanical governor at 3300RPM so my dana 70 rear and 60 front are 3:54 ratio with the Getrag 5 speed NP205. At reline 3300 rpm it does 86mph, stock it had 160hp and 400ft/p torque now it has 475 hp and 780 torque i put the p7100 pump in it
it came with the holset turbo without the wastegate non intercooled
i ordered it late 89 turned the pump up and put an AAron Michael Kuit aftercooler in it it has over 800,000km
with 4:10 top speed is 82mph
aaron
ps it can do 3000 all day long

[Captain23]

Prado t,

How hard was the brake conversion? Did you cut the axles?

The donor for the Engine was a 93 Dodge, I'm pretty sure its a 6BT not a BTA

need to get this right, 2000 is a lot farther from 3300

[Tapage]

Wou !

1. BF1A T-case can handle this power I'm pretty sure ( the stock power of course )

2. MAF Sells OME or Dakar .. ir are new springs are Dackar but I recomend AAL in front for the 6BT weight.

3. I would keep the NP205 with D60 or Factory TLC with BF1A T-case .. so leave it as is ( I thought with NP and Dana axle )

4. 3.73 as much with 35" tires
Plase take pics and post here ..

[Captain23]

Should I cut the axles?

[prado t]

Originally Posted by Captain23

Prado t,

How hard was the brake conversion? Did you cut the axles?

The donor for the Engine was a 93 Dodge, I'm pretty sure its a 6BT not a BTA

need to get this right, 2000 is a lot farther from 3300

the 6bta is in the dodge still i was only mentioning that they have a 3300 rpm and it doesnt matter if it has 160hp or 500hp 3300 is max rpm or top speed.
my appologies for the confusion
aaron
ps the 6bta is 1990

[Dieseltim]

As far as the 6bt and SVO PLEASE don't do that to a great engine. I have almost 5 yrs experince with SVO/ WVO and Biodiesel, if you do any kind of alt fuel. I highly recommend Biodiesel. From all the data that I have collected it is a proven fact that SVO WILL coke up the insides of the engine, and injectors. It may take 30,000 mi but it will happen. My first (only ) WVO test was an 85 vw golf and after 10,000 miles and about a yr, it had lost a lot of compression and was burning lots of engine oil the only thing left to do was rebuild the engine.

I got a call just this week from a guy that was working on a 92 dodge that had been run on SVO for only 500 miles, it had broken the rotary injection pump and clogged all the injectors.

As far as your conversion goes, I would love to see the pics. Sounds like a great conversion and hope to see it soon.

Dieseltim

[Captain23]

Originally Posted by Dieseltim

As far as the 6bt and SVO PLEASE don't do that to a great engine. I have almost 5 yrs experince with SVO/ WVO and Biodiesel, if you do any kind of alt fuel. I highly recommend Biodiesel. From all the data that I have collected it is a proven fact that SVO WILL coke up the insides of the engine, and injectors. It may take 30,000 mi but it will happen. My first (only ) WVO test was an 85 vw golf and after 10,000 miles and about a yr, it had lost a lot of compression and was burning lots of engine oil the only thing left to do was rebuild the engine.

I got a call just this week from a guy that was working on a 92 dodge that had been run on SVO for only 500 miles, it had broken the rotary injection pump and clogged all the injectors.

As far as your conversion goes, I would love to see the pics. Sounds like a great conversion and hope to see it soon.

Dieseltim

Pics on the way, were towing it up to Portland Wednsday,
I've heard stories both ways on SVO, i know a sweet biofuel mechanic in Corvallis who specializes in SVO, definitely going to get his opinion before doing anything, BIodiesel is a given though!

Was your system in the golf preheated? tank and all lines? was it clean oil? Did you have larger injectors, hotter glow plugs?There are a lot of factors you know, I'm not going to write off anything yet,

[GLTHFJ60]

This is going to be an excellent rig.

Are you going to have to strengthen the frame with the extra power?

[Poriggity]

I like the idea of this.. Can't wait to see it. Sounds sweet!
Scott

[Captain23]

Originally Posted by GLTHFJ60

This is going to be an excellent rig.

Are you going to have to strengthen the frame with the extra power?

No I think the frame should be fine, its completely rust free, its from Sisters, OR high desert.

Pics tomorrow. :-)

[Ducks]

Let us know what you decide about the SVO vs biodiesel thing. I've been researching it for a while. Advantages and disadvantages to both. It sounds like a great project.

edit - I just read your sig line. It would be great to hear about how the SVO goes (install, etc.).

[natdog37]

PICS PICS PICS! I must see PICS! I am seriously thinking about doing this. If you don't mind i'd like to ask how much you will have invested after all is said and done? Also is it for sale?
(I had to ask)

[cody c]

i second the pics request.
please take lots of pics, and please post lots of pics.
im enjoying hearing about this swap, you'll definately like the finished product!

[Captain23]

Pics on the way!! Waiting to get them from the dude that towed her up to portland, soon soon soon, and lots of them! maybe tonight!!

[Captain23]

For all you interested in the Cummins 6BT, theres another one for sale, its got tons of extras like the propane injection kit- a $1400 kit!, custom exhaust, intake, air box, hp chip. Only thing is its still in the Dodge, but its loaded! Dana 60 front ,70 rear w/locker. drive lines, no tranny. Body was rolled, everything else is fine.

[Captain23]

Finally some PICS!!


Shots of the truck on its way to PDX, Dana 60's still on it, lifted 4 inches and SOA!



LC axles ready to go back under sitting in front out of another FJ- rebuilt rear w/locker



Oh yeah those tires/wheels are for sale, I think he wants 800 for them 38 super swampers on 16.5's.
more tomorrow!

[dieselcruiserhead]

Gifu is still right about that in my opinion. You will get best mileage gearing for about 1800 rpms cruising highway.. I would say leave the 3.73s, I am in the same boat, wish there were 3.73s for my 80 axles as well...

[Tapage]

Woou .. ! I thought it have pretty much lift for those tires .. but if you are selling it, what come ?

I wanna see those driveshafts .!

BTW this oil pan looks pretty huge

[GLTHFJ60]

Why are you putting the regular LC axles back in? Since you already have the stronger Dana axles, why not just leave them there?

[Captain23]

Originally Posted by GLTHFJ60

Why are you putting the regular LC axles back in? Since you already have the stronger Dana axles, why not just leave them there?

I want to have a cummins powered landcruiser not a dodge with a landcruiser shell, and I wanted less weight, for milage, and the dana's stick out about six inches on each side, so i'd have to add fender flares.

So I'm going with longfields and new 30 spline axles to beef them up. The dana's just sold, the wheels/tires are still around. But this means i need an adapter for the toyo transfercase. anyone have one????

And the NP205 case is for sale. $500- I'll post up in the class. about it.

[Captain23]

Finally some pics!!! Were still waiting on the axles and longfields and t-case, going with a centerforce clutch kit, advanced adapter, add a leaf with stocks, hysteer kit, Should be cracken this next week. Until then, heres some pics.