fj80 cummins swap

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Joined
Oct 6, 2009
Threads
21
Messages
152
Location
Eugene, Oregon
its been a while since I have been on here I had good momentum on my build then it all came to a halt ounce I installed the motor/drive train then again after modifying the tcase and finding I only have low range that’s when all my momentum went out the window its been a year now and I’m ditching my "pipe dream" of running a getrag and a np205 with stock rear end. It could be done but it would be too much of a hack job and moving the gas tank.
I will start at the beginning.
about 5 years ago my buddy built a 60 with a 4bt it was freakn awesome, he sold it, so when I found out he was building an 80 with a 6bt, 700r4 and 60 t case I was helping and learning with aspirations to build my own this matte black 6bt with 700r4 fzj80 is my avatar and was featured in march or Feb Petersons 4X4 matte black 80, that too was sold, when we delivered it to north Hollywood I picked up my 91fj80 with 261k miles on it I really didn’t know if it would make it back, It had all kinds of groans in the drive train but made it 1000+ miles back to Oregon. I immediately took it out wheelen to see if I could break it. I will say for the two weeks of hard wheeln I put it through nothing broke. That is a true testament to the quality of the land cruiser!
I then tore it down rebuilt the first gen non intercooled Cummins took care of the KDP and installed the 3" body lift and the motor/drive train. ounce the drive train and motor where installed I noticed a problem, one I should have noticed well before this point, the tcase is a centered rear out put not good,, I need a passenger drop rear output. After the initial shock I start to research, after many nights of manning the keyboard I find out I might there is hope yet. I can use a few parts from a np200 and get my passenger drop out of the np205 I order up all the pieces I will need perform the “abortion” and install the tcase only to find I only get low range out of the basterdized tcase. at this point I’m pretty frustrated I go to and call every machine shop I know of, one takes the job to make me a shaft that will support the np205 gears and uses the np200 rear bearing carrier thus giving me my dual passenger drop np205. I’m stoked, that wears off after about six of waiting on the machine shop. My original plan was to get it running and moving under its own power wheel the crap out of it fixes what breaks and paint it after a while. I got tired of waiting and figured I would use the idle time to paint and do some tinkering. While waiting I plumb and install the fans build a radiator and so on. I get it running only to find lots of oil getting in the radiator; my first thought was I had a leaking head gasket. I put a new gasket in with new head bolts and it still blew oil in the water. after scratching my head for a while and lots of late nights filled with beer and frustration I pulled the oil cooler (which I didn’t even know was in there, a buddy told me to check it) only to find it had a pin hole. Swapped another in from a donor block and viola no more "blow by” it’s been about a year now of driving by the shop and looking at my bruiser sitting and I just can’t take it. I’m pulling the plug on my uni-corn shaft and going with what I know works nv4500 with a 60 or 62 tcase.
I don’t have a whole lot of picks but here is what I have I hope to have this done here in the next few months.

these pictures are in L.A right after we picked up my 80. the black one hosed an A/C relay causing the cooling fan not to work luckly autozone carrys bosch relays.
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building a radiator 101... motor rebuild. these cummins motors are so...simple its great!
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installed j springs front and rear with 1" spacer up front didnt like the stance kept the j's in the rear went with 5" comp coils no spacer it sits level now.

my buddy stole my original air intake for one of his projects so we had to fab that one up i think i will keep it...made it in 5 minutes out of left over intrcooler pipe.
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paints finished and thats how its been sittn for about six months well I hung the fenders but not much more than that.
im now on the search for a 60 or 62 seies t case and nv4500 and AA
im sure i will have to have my drive line re made with a differant end but i hope this goes smotther than it has.
for rims and tires i have 6, 37x12.5, 17" cooper stt i think they are 12.5 idk its been a year since i bought them, and fj cruiser 17" steele wheels im going to see if i can get away without running spacers.

do the fj62 servo controled tcases hold up?
does the fj62 t case servo just control the high and low?
and 2wd/4wd is still controlled by a "stick"?




"we" have built a couple cruisers gasers and cummins swaps

fj60 4bt trans? 60tcase still running strong no probs i know of, its back east somewhere the guy loves it.

94 fzj 93 5.9 cummins 700r4 60 t case, it was beutiful but laked exseleration and hosed 3rd gear within a 5k miles

91 fj80 this build

96 fzj80 94 5.9 cummins custom front mount intercooler,nv4500, 60 tcase dont know where it ended up but it was a blast to drive the five speed really help with exseleration.

all the diesel conversion where full drive train and cosmetic restoration/swaps all black exsept mine. a black vehicle looks great on the street but run it though the brush and it looks like poo.

well i hope you enjoyed my thread i will post pics and try to keep updates as i go.
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Yours is going to be almost identical to mine when your done, except for the fresh paint!

I did the denny T fuel pin a while back, smokes a bit more but really wakes up the old oil burner.

Dont know much about the 62 series cases though.
 
You are living the dream. So many people would have given up on it long ago. My dream is a p7100 pump 12 valve with NV5600 in my 80...You are going to love this thing.
 
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Keep up the good work .. I may go this route once my engine implodes ...
 
Sweet build! You should link it to the diesel section....
 
I have dibs on a 1989 Cummins 12 valve with 115k miles on it for my 1993 Cruiser, so this thread is very interesting to me.

Have you sorted out how you'll install your tranny, clutch, etc? Will you be re-gearing your diffs?
 
thanks guys,
i did mess with the pump a little 4200 spring and turned out the full fuel srew, few other things ,id like to run a snokel but i dont know if it will flow enough air,
as for the gearing with the 37's i dont think regearing will be needed.
our last one had 35's and went 85 mpg up the grape vine got 20 mpg on avg from OR - LA.
i allready have the third pedal installed its out of the dodge.
as for the trans t case mounting its pretty cut and dry,get an nv4500 that came off a cummins and it bolts right up, AA and a 60 tcase. last time we had to space the cross member down anout 1/2" it a long ways from done but im exited again and i hopei can get it moving soon then its off to S.O.R.D to link the suspension as it all out of wack with the comp coils

did you order the rebuild parts for the motor directly from cummins?

yes there is a cummins shop close by, the head gasket is from the guy that rebuilt the head, i got some parts from rock auto there prices are fair on clutches and some other things,
 
When you pulled the original motor and all its related wiring, how much was the motor ecu wired into the rest of the truck? Any electricals (warning lamps, etc...) not working/ on since the swap?
 
the non intercooled cummins are really simple, but your ECU will throw a CEL, as it will think there is something wrong with the 3FE/1FZ. The cummins needs a wire for the fuel shutoff + one for the starter.
The rest is for the gauges, back up lights/reverse etc.
You wont need a fuel pump, the motor has a mechanical one on the block, so you dont need that, the fuel filter is on the side of the block so you dont necessarily need the one on the frame.

The more difficult stuff with the engine is getting it to fit/motor mounts, getting clearance for your rad fan (electric fan takes less room) your coolant lines, getting your starter to clear the frame rails, and getting the driveline lined up/crossmember built. I had to caress the trans hump/firewall a little with the "knock-ometer" as well.

The tach is a bit of a pain to get working properly as well.

Actually moddifying the transmission hump for a manual is a little bit of work too. But the electrics are pretty simple.
 
When you pulled the original motor and all its related wiring, how much was the motor ecu wired into the rest of the truck? Any electricals (warning lamps, etc...) not working/ on since the swap?

the wirring is not realy an issue, modify the stock in tank sending unit (take the fuel pump off) by using the stock sending unit the fuel gauge is the same, i thought about keeping the fuel pump as late model cuminns motors have a pressurized fuel system. but i want to have minimul electronics.
the tach is the hardest/easyiest part of the elec depending how much you want to spend, the alternator needs a volt regulater to charge properly you can get them at any auto parts store for around $20.00
i went with electric fans to keep it cool on the trails and it saved me some room,
the a/c pump clearance in relation to the frame is very tight hooking the A/C up is also another issue custom lines need to be made.
the dash will throw lights that are no longer relivent just take the bulbs out. as for back up lights thats an easy fix with a pressure switch. the 91 fj80 has a stand alone body control modual. i took the ecu completly out and taped in to the harness plug and made my own harness for the few electrical items on the motor,
the gauges are a little tricky to get to work, in order to use the stock 3fe coolent and oil pressure gauge you need to adapt them to the cummins block and find the right wires in the stock harness via a power probe, this is the most accurate way to use the stock dash as the sensors are calabrated to work with the stock gauge cluster, all in all the first gen cummins swap is pretty straight forward getting the motor to fire is the easy part. i go down and fire mine up evry month or so to keep it fresh, and it allways amases me how easy it is to get it to fire, turning it over is not so easy,
getting every thing to work and look "stock" takes some injenuity.


the non intercooled cummins are really simple, but your ECU will throw a CEL, as it will think there is something wrong with the 3FE/1FZ. The cummins needs a wire for the fuel shutoff + one for the starter.
The rest is for the gauges, back up lights/reverse etc.
You wont need a fuel pump, the motor has a mechanical one on the block, so you dont need that, the fuel filter is on the side of the block so you dont necessarily need the one on the frame.

The more difficult stuff with the engine is getting it to fit/motor mounts, getting clearance for your rad fan (electric fan takes less room) your coolant lines, getting your starter to clear the frame rails, and getting the driveline lined up/crossmember built. I had to caress the trans hump/firewall a little with the "knock-ometer" as well.

The tach is a bit of a pain to get working properly as well.

Actually moddifying the transmission hump for a manual is a little bit of work too. But the electrics are pretty simple.

with the getrag i have in there now, i was able to make the stock crossmember work with the stock holes just made my own rubber mount, when using the nv4500 the crossmember needs to be shimmed down about 1/2" with a 3" body lift there is just enough room for the motor. depending on where you mount the motor you may run in to clearance issues with the front diff, front crossmember thing (its a tube that conects the frame rails) valve cover to fire wall air intake to underside of hood, its a happy medium i put the A/C pump as close to the frame as possible just enough space to remove and install the pump if need be, i used the flat motor mounts and did not cut in ti the frame only added to it. the last one me and my buddy finished we used the "round" mounts i believe they changed in 1993 we had to cut in to the frame and set part of the mount in the frane it is alot more succure but i didnt want to do that i will have a safty strap sort of speak to limit the motors movement under rough condition. his mount will probably last twice as long as mine but to me it was to much work for not enough benifits, and i allready had the flat mounts.

my buddy and i are very handy, and the swapp would be a breeze if money was not an issue and we could order all the "correct" parts needed and have them all infront of use.
the trick is knowing which parts will make your swapp go smoother we have done enough of these swaps we know what work and what does not.
the last one we did was by fare the best "parts combo"
however it was a 2nd gen motor and in my opinion there is to much going on, and the engine bay looks very clutered with all the extra B.S they added. in my mind the first gen is the best, it can be setup to have ZERO electrical parts. and to me that could be the differance between a great trip and a not so great trip,
and hey if a nuke goes off my cruzer will still be maken noise. :steer:
the only electric part on the first gen is the fuel cylinoid switch which can be converted to a manual lever.
 

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