FJ80 6BT project planning questions.... (1 Viewer)

[xoverland]

I have a 91 FJ80, and I am looking at a good deal on a 97 cummins ram 2500.

I want to do the swap in a few stages...

Fisrts stage, just get the cruiser running, I am fine with 2wd, for the time being, but it would be nice if there was a cheap way to keep 4wd.

Second step 4wd and axle and suspension upgrades... Possibly portasl, possible 3 link... But that is a while down the road.

Background... Cruiser is my wife and mine's daily driver... Our only daily driver... We need better MPG.


I would like to keep the cruiser automatic... and hupefully one day all wheel drive...



So It seems like the the 47rh is a good transmission to go with.

My immediate problem with the 4wd is the Passanger side drop.

I dont really want to invest in adapters/tcase that go this way as I want to eventually put a Dana 60 up front with will be a drivers side drop.


Questions:

1. Is there a transfer case that can be switched from left side to right side drop and vise versa... This way I would not be afraid to invest in a tcase if I knew I could still use it with a Dana 60 axle.

2. Is the Dana 60 on the Dodge able to be adapted to the Cruiser. I Know it could probably be narrowed, and have radius arm mounts and spring perches put on. But is it economical to do that, or just have one custom built.

3. Is there a way, or is it a good Idea to adapt the 6bt to the A440F?

4. Is there a way to adapt the HF2A to the 47RH?

5. Which tcases have a center diff that would be practical for this application.. Off the top of my head, the only ones I know are LC tcases and the H1 tcase.

6. Am I crazy?


Ryan

 

[StevoJonesFJ60]

Background... Cruiser is my wife and mine's daily driver... Our only daily driver... We need better MPG.


I would like to keep the cruiser automatic... and hupefully one day all wheel drive...

Questions:

1. Is there a transfer case that can be switched from left side to right side drop and vise versa... This way I would not be afraid to invest in a tcase if I knew I could still use it with a Dana 60 axle.

I have not heard of one. Most are designed to be used one way to ensure proper oiling of the gears.

2. Is the Dana 60 on the Dodge able to be adapted to the Cruiser. I Know it could probably be narrowed, and have radius arm mounts and spring perches put on. But is it economical to do that, or just have one custom built.

It all depends on how much you are willing to spend. If you could live with a leaf sprung suspension it can be done fairly simply and easily. Other options like reusing the coil system from the 80 are possible just more time consuming, all it would take is putting coil buckets on the axle and attaching radius arms or a 4 link system

3. Is there a way, or is it a good Idea to adapt the 6bt to the A440F?

Not that I am aware of, I also am not sure if the A440F would hold up behind a Cummins.

4. Is there a way to adapt the HF2A to the 47RH?

No Clue

5. Which tcases have a center diff that would be practical for this application.. Off the top of my head, the only ones I know are LC tcases and the H1 tcase.

You could always run a divorced NP205 with a strong 2WD transmission.

6. Am I crazy?

Possibly.

Ryan

Also what are your planned uses for the Truck and how much HP are you looking to get out of the Cummins. These answers will dictate a good portion of how the truck should be built.

 

[xoverland]

Also what are your planned uses for the Truck and how much HP are you looking to get out of the Cummins. These answers will dictate a good portion of how the truck should be built.

Probably about 300hp, but Mileage is the primary reason I want to go this route. It will be a family primary vehicle.

I would like to get as much HP as possible with getting too far below 20mpg.

I will be using it for wheeling as well, in the end... But I understand if i have to wait a bit to get stuff beefed up.

So daily driver...

 

[cody c]

I think your expectations are a bit off.

The cummins is a beast, sure it has lots of power and its a bit more efficient than the 1FZ. Its not an ideal daily driver to the grocery store or to work for the wife though. It is well suited to towing, idleing all day on off road trails etc. But for a DD the 5.7 or 4.7 would be my first choice for something the wife would be driving alot. And then 300hp out of a cummins, well your looking at 500 or 600 torque. The rest of the drivetrain is going to have to be real beefy to take the weight and torque.

If this is your only vehicle between the two of you and you want to get all this work done, your gonna need another vehicle. A cummins swap and one off suspension and then finding portals while still having transportation is going to be interesting.

Not that this cant be done, but it is no small task, and modifying the suspension and adding portals or 1 ton+ axles is going to take from its handling ability, something your wife may not appreciate when running out for milk or ketchup, or on the freeway. Also, its likely you have some bugs to work out in the next few years. Have a look at dora's build thread and you will see all the work into it, or brokenparts's build thread.

For the drivetrain and axles, your best off finding a donor vehicle and swapping the works in, then trying to reuse the 80's suspension.

 

[xoverland]

I think your expectations are a bit off.

The cummins is a beast, sure it has lots of power and its a bit more efficient than the 1FZ. Its not an ideal daily driver to the grocery store or to work for the wife though. It is well suited to towing, idleing all day on off road trails etc. But for a DD the 5.7 or 4.7 would be my first choice for something the wife would be driving alot. And then 300hp out of a cummins, well your looking at 500 or 600 torque. The rest of the drivetrain is going to have to be real beefy to take the weight and torque.

If this is your only vehicle between the two of you and you want to get all this work done, your gonna need another vehicle. A cummins swap and one off suspension and then finding portals while still having transportation is going to be interesting.

Not that this cant be done, but it is no small task, and modifying the suspension and adding portals or 1 ton+ axles is going to take from its handling ability, something your wife may not appreciate when running out for milk or ketchup, or on the freeway. Also, its likely you have some bugs to work out in the next few years. Have a look at dora's build thread and you will see all the work into it, or brokenparts's build thread.

For the drivetrain and axles, your best off finding a donor vehicle and swapping the works in, then trying to reuse the 80's suspension.

Thanks for the reality check, I need those from time to time...


I do understand this it is a HUGE project. I was planning on getting another car to drive while the project is underway.

So, I was thinking, If I left the 6bt stock for the initial install, left the cruiser 2wd (not worrying about passenger side drivers side drop, and just use the dodge tcase) I would think that the stock rear end on the cruiser would be able to handle the power.

I could also easily swap to a full float cruiser rear end for a bit more strength fairly easily. (I think, same mounts and everything correct??)

As far as portals go, that is while down the road...

So, I have found a donor vehicle, 97 Dodge 2500 Cummins 4x4. It runs, has an NV4500. I would rather have an auto.

So Plan was, buy this truck, drive it over the winter, making sure everything functions good, runs good, tuned up... That way i know what I have before I start. Then next spring/summer , swap in the cummins, 47rh, leave 4wd alone. This should be pretty straight forward.

After that is working running, and Im happy with it, then worry about axles. Dana 60 front and rear. (there are bolt on portals for these, but$$$$$)

Then build up the motor a bit...

So yea....

Is that a bit more realistic?

Ryan

 

[Kurtis]

For what you want a GM 6.5 would be a much more economical choice. Do the research on them fix the couple little issues they have and it would be a very reasonable swap and crank out good power and excellent mpgs. Their kinda like the ford 6.0, they deserve the bad rap they got but their issues can be solved fairly easily and then are great.
The cummins is my favorite diesel hands down but in a cruiser the 6.5 makes a lot of sense. They can be had cheap, They fit anywhere a sbc goes and they get great mileage. They are also quite a bit smoother and quieter. This also solves your axle and drive shaft issues. 80s go everywhere and have excellent flex to start with so for an Overland vehicle there is not a huge reason to change that component.

Look around there have been a few swapped in 60s and 80s with excellent results on here. I swapped a tbi 5.7 in my 60 but the 6.5 was my second option. I drive my cruiser less than 3000 miles a year now so I didn't have much of a need for the diesel.

 

[xoverland]

For what you want a GM 6.5 would be a much more economical choice. Do the research on them fix the couple little issues they have and it would be a very reasonable swap and crank out good power and excellent mpgs. Their kinda like the ford 6.0, they deserve the bad rap they got but their issues can be solved fairly easily and then are great.
The cummins is my favorite diesel hands down but in a cruiser the 6.5 makes a lot of sense. They can be had cheap, They fit anywhere a sbc goes and they get great mileage. They are also quite a bit smoother and quieter. This also solves your axle and drive shaft issues. 80s go everywhere and have excellent flex to start with so for an Overland vehicle there is not a huge reason to change that component.

Look around there have been a few swapped in 60s and 80s with excellent results on here. I swapped a tbi 5.7 in my 60 but the 6.5 was my second option. I drive my cruiser less than 3000 miles a year now so I didn't have much of a need for the diesel.

Thanks for the Ideas on other options.

I was a mechanic in the Army. Spent a year pretty much only working on 6.5's. It was not a good experience for me.

Im not saying that they are a sucky motor, but I did not have good luck with them, and I now have PTSD. Not from getting shot at, or seeing any real bad, but from working on HMMWVs.


I have see the longevity and endurance of 6bt first hand, and I love the engine. I also have a cheap running complete donor vehicle lined out.

I may have been somewhat misleading in my second post... As for right now, I am looking for the most economical way to swap in the 6BT. As for the horsepower, that is not the largest concern. Drive-ability and MPG, are top priority. I would like and much HP and trail worthiness I can get, but I don't want 10 MPG and a top speed of 55Mph.

I do understand that Lifted 4x4s don't always have the best manners on the road, and I'm not looking for sports car handling.

I don't plan on running anything bigger than 35's on the road, may be something a bit larger for trails, but I would like to keep tire prices cheaper.

Ryan

 

[Kurtis]

Out of the box the 6.5 sucks that is what I am saying and I would never buy one in a truck but for a swap they are a near perfect setup. They are however reliable with the small changes and cost much less than a 6bt swap.

If your set on the 6bt have you read some of the swap threads? If I were to do it it would be this way.

https://forum.ih8mud.com/80-series-tech/448564-fj80-cummins-swap.html

The best swaps for a non trailered vehicle that will be used for extensive road travel have the least one off solutions and this guy did a great job with his. Its for sale as well. The 80s suspension works so good I would try to leave it.

Defiantly do not do the swap half way, 2wd then 4wd. It will cost much much more in the end. You will end up re doing exhaust, drive shafts, maybe even engine placement, then the lines, etc. Its defiantly an all or nothing affair.

 

[Elbert]

there is a guy in process of doing a 6bt swap right now ...hope you are reading his thread...

I'm thinking you better have a good trans to mate with the 6bit...like one that is made for it or they make some adapters for.. I'm guessing that the torque output will kill a "normal" trans. I think guys go with a NV4500 or whatever the newer style dodge 5 or 6 speed manual trans is that was used with the 6bt.

I would not run a toyota auto trans....I don't think it can handle the torque and I'm not sure if they is a way to mate the trans with the engine or even it it would be a good move to do so. Maybe the auto trans from a dodge 2500?

https://forum.ih8mud.com/hardcore-corner/570248-stevos-6bt60-build-thread.html

 

[Tapage]

as you are looking for ideas and opinions here is mine ..

If you are targeting DD and fuel economy why not 4BT .. if you are in love with the cummins line .. I mean smaller engine but still very capable.

Another thought will be for isuzu engine .. Clint did with good results in his 60 series .. cheaper and will be step forward on fuel economy ..

just my .002 cents ..

 

[xoverland]

as you are looking for ideas and opinions here is mine ..

If you are targeting DD and fuel economy why not 4BT .. if you are in love with the cummins line .. I mean smaller engine but still very capable.

Another thought will be for isuzu engine .. Clint did with good results in his 60 series .. cheaper and will be step forward on fuel economy ..

just my .002 cents ..

I have looked into doing a 4bt in the past, and I think it is a great option. My main draw to a 6bt at this point is the cost...

I have a full, running donor truck for 2,000 ish, I haven't nailed down the price for sure, but somewhere in that neighborhood.

That gets me most evrything I need. It has a dana 60 front, if I end up needing it, dana 80 rear, NV4500. Even if I dont want the NV4500, I can still sell for trade it to get whatever transmission I want.

It has AC....

I can used the Dodge for the time being, and make sure everything is tip top in it before I do the swap.

Having a running, working platform to start with will make the swap go a little smoother, I THINK???




I asked some questions over on 4bt swaps, and there is apparently an adapter from the dodge 47RH auto to the Cruiser tcase.

This would make things a bit smoother

Also, apparently there will be an adapter coming out soon for the cummins to bolt right up to my transmission....

I am a little nervous about this....

Would the A440F be able to handle the 6BT in sock form??



Either one of those 2 options would make things go alot cheaper and easier!!


Ryan

 

[StevoJonesFJ60]

The Dana 60 in that dodge isn't great for a wheeling truck. It has ball joints and that crazy front axle disconnect thing. If you plan on wheeling the truck with a heavy engine like a 6BT in it I would suggest getting a Kingpin 60.

Also a Dana 80 is pretty big, you might be able to shave it for some extra clearance but if your max tire size is 35" you will be dragging that thing all over the place.

I personally wouldn't trust the A440F behind a cummins. Its going to put out a lot of torque, approx 400 ft-lbs at low rpm. If you ever plan on turning up the 6BT It would never hold up and you would have spent a bunch of time and money for a setup that wouldn't last. I would put something in there that you know can handle the output of the motor.

Depending on where you are out of you can probably sell that NV4500 for plenty of $$$ and use that to buy yourself a new transmission.

 

[cody c]

Having a running, working platform to start with will make the swap go a little smoother, I THINK???


I asked some questions over on 4bt swaps, and there is apparently an adapter from the dodge 47RH auto to the Cruiser tcase.

This would make things a bit smoother

Also, apparently there will be an adapter coming out soon for the cummins to bolt right up to my transmission....

I am a little nervous about this....

Would the A440F be able to handle the 6BT in sock form??



Either one of those 2 options would make things go alot cheaper and easier!!


Ryan

The A440F will handle a 6BT in somewhat stock form. Been there done that.

My 80 had the A440F with a custom torque converter from OZ when I first got it. I think it was from wholesale auto, I cant remember I sold it a year or two ago with the trans for about $400.

It came with a one off bellhousing adapter, the crank drilled and tapped for the 6 bolt pattern, a machined cylinder that fit into the crank and the toyota flexplate.

It worked alright for a couple years and then I broke a flexplate. I went thrpugh a couple more custom or modded flexplates and then I went to the NV4500HD from a 97 cummins.

I think most of the issues with the flexplate were related to poor alignment between the 6BT and the trans from a scratched together bellhousing adapter that wasnt perfectly done.

Anyway, now Im running the NV4500 with an AA adapter to a 60 series split case, and no looking back. Also swapped the front hubs from full time flanges to part time aisin's.

I do have a brand new flexplate from the cummins still (new from cummins parts but never installed), and I may have the old botched adapter plate somewhere in the garage if you are inclined to buy some parts for your build. But I am a fan of the 5 speed OD NV4500 trans personally.

 

[Tapage]

Cody you spot important issue here .. any gasser auto tranny A440 or A442 ( A343 as well ) will be set for gasser 1FZ-FE power band that it's quite off compared to any cummins engine power band ..

Edit: speaking Toyota trannys in stock form

 

[cody c]

Cody you spot important issue here .. any gasser auto tranny A440 or A442 ( A343 as well ) will be set for gasser 1FZ-FE power band that it's quite off compared to any cummins engine power band ..

Edit: speaking Toyota trannys in stock form

ya, shift points (rpm band) is differenet for the 3FE as opposed to the 6BT.

Rev limiter spring in stock shape for my 91 6BT is 2800. There is aftermarket rpm springs of a few different ranges that can take you to 4000, but even then with the WA torque converter shifting wasnt great with my truck, maybe it could have been adjusted better, but it was less than perfect for me.

You get some tires yet tapage?

 

[Elbert]

If you have a doner truck with all the parts plus nv4500....then I think you have your parts ready to go with a proven solution, no guess work moving forward regarding transmission....

 

[xoverland]

If you have a doner truck with all the parts plus nv4500....then I think you have your parts ready to go with a proven solution, no guess work moving forward regarding transmission....

Ok so scrap the A440 Idea....

So I will have the NV4500, I can stick with that, I dont really mind, but the wife might not like it. It is kinda nice being lazy with the auto. and the only real complication would be trading the NV4500 for the 47RH (the easiest way/strongest tranny that will bolt up to the cummins with minimal electronics.... form what I have read so far.)



I guess it is also easy to beef up, it has a .69 OD, and a lockout plate.

Any quarrels with this tranny?

And then I will need to figure out this adaptation to the HF2A TCASE.

Ryan

 

[Tapage]

You get some tires yet tapage?

not yet .. decide to wait if Interco get back on LTB 40" on production as promised ..

Any quarrels with this tranny?

you can't go wrong with NV4500

 

[xoverland]

you can't go wrong with NV4500

I was Talking 47RH auto

Ryan

 

[Tapage]

I was Talking 47RH auto

upps ... my bad ..