Time to ask some questions

[scout4bta]

What would you say your swap cost when all was said and done?

In 2001 I bought The 4BT used, was a 105hp with a VE pump, delivered $3000.
You'll need a transmission adapter, about $250
Starter motor. $85 and up.
Flywheel $150 ?
Clutch cover and clutch disk ?
5 speed manual trans, NV4500. $2000
Atlas 2 speed T case $2500

The cheapest way to go is buy a used Dodge Diesel pickup or a complete power train and you get all the above parts for a lot cheaper. And or sell the 6B and then buy a 4B, every thing will bolt up.

Note: I had specific time window to get the project running and could not wait to scrounge for used parts.

[Junkers456]

I'm speaking from owning 3 Dodge Diesel trucks. My first Diesel conversion, 20 years ago was with Cummins 4BTA into a 1980 Scout.

These are my thoughts on using a Cummins B series for the Conversion.

Your Fuel milage may vary. Expect low 20's to high 20's. I've got 20 years of driving my Scout with a 4BTA, 5 speed trans and that's what I averaged. It had a 40 gal tank, 1000 mile range. You'll need to match the axle gearing, tire size to the diesel rpm range.


Power: Love the low end torque. I ran the factory Dana 44's on my Scout with out problems. The trans, especially an automatic must be Diesel specific, the low end torque will tear up a gas trans and the torque converter must be Diesel specific to accommodate the lower rpm. A manual trans needs to be a close ratio to accommodate the narrow power band of the Diesel.

Cost; Can you justify the cost, probably not unless you have all the "parts" laying around.

What would you say your swap cost when all was said and done?

[scout4bta]

I have been doing some digging on here, and have come to a conflicted thought process: is a diesel swap really worth it? Or would it be best to do a gas engine swap? My main issues here are:
1) fuel mileage
2) power (not a huge deal, but it will be a hunting rig so I want to be able to go just about anywhere in upwards of one foot of snow)
3) cost of swap
And the biggest issue, 4) time and ease of swapping

I love diesel engines for their roar and the sweet, sweet smell of that oily black smoke, but I'm not sure if it's the most economical option for what I want. Thoughts?

I'm speaking from owning 3 Dodge Diesel trucks. My first Diesel conversion, 20 years ago was with Cummins 4BTA into a 1980 Scout.

These are my thoughts on using a Cummins B series for the Conversion.

Your Fuel milage may vary. Expect low 20's to high 20's. I've got 20 years of driving my Scout with a 4BTA, 5 speed trans and that's what I averaged. It had a 40 gal tank, 1000 mile range. You'll need to match the axle gearing, tire size to the diesel rpm range.


Power: Love the low end torque. I ran the factory Dana 44's on my Scout with out problems. The trans, especially an automatic must be Diesel specific, the low end torque will tear up a gas trans and the torque converter must be Diesel specific to accommodate the lower rpm. A manual trans needs to be a close ratio to accommodate the narrow power band of the Diesel.

Cost; Can you justify the cost, probably not unless you have all the "parts" laying around.

[Heep-J4000]

The reason why I did go for a 12 valve Cummins engine with nv4500 for my jeep is durability.

My 73 j4000 original had a 360/T15/D20
Had some issues with the T15 transmission through the years and after thirteen years of daily driving the 360 was done.
So instead of putting 10.000 into a engine rebuild that still stays almost 50 years old I chose for a Cummins engine with NV4500/np205 combination for less

I loved the 360 V8 rumble trough the sidepipes and do miss that , but it stays a daily work truck so in my situation it's more useful with a 12 valve Cummins.

[Junkers456]

I spent a lot of money and put a 12valve and a NV4500 5 speed in my 87 j20 about 8 years ago. The "cool" factor was great but it had it's drawbacks. It is heavy and noisy and in order to get some more power out of it, which it needs, I'd have to dump even more money in to it. I also had to remove the heater unit in the engine compartment in order to fit in the turbo, I used an aftermarket in cab unit that didn't work very well besides the fact that the diesels take a long time to heat up. Everyone here thinks I'm nuts but I'd finally had enough and am in the process of taking out the diesel and installing a 401 but I'm keeping the 5 speed in it.

Were trying to stay away from the 6BT... it can be made to fit, but we want to be able to drop something in a bit easier. The smaller, the better, ya know? If a cab-off chassis came along for a good price with low miles, we may consider it, but I feel it would end up looking like Jeremy Clarksons "The Discovery" (if you know, you know), which... well, it leaves something to be desired.

[Junkers456]

Can't argue with the money thing.

I bought mine back in the 90's. New plus the used one I bought previously. I don't remember how much and try not to.

Know what you mean about wiring. Mine takes none, other than the starter and plugs. The fuel cutoff is manual.

Pretty much what were looking for right there. More wires=more problems you can't fix easily on the fly.

[conehead]

I spent a lot of money and put a 12valve and a NV4500 5 speed in my 87 j20 about 8 years ago. The "cool" factor was great but it had it's drawbacks. It is heavy and noisy and in order to get some more power out of it, which it needs, I'd have to dump even more money in to it. I also had to remove the heater unit in the engine compartment in order to fit in the turbo, I used an aftermarket in cab unit that didn't work very well besides the fact that the diesels take a long time to heat up. Everyone here thinks I'm nuts but I'd finally had enough and am in the process of taking out the diesel and installing a 401 but I'm keeping the 5 speed in it.

[SJTD]

Can't argue with the money thing.

I bought mine back in the 90's. New plus the used one I bought previously. I don't remember how much and try not to.

Know what you mean about wiring. Mine takes none, other than the starter and plugs. The fuel cutoff is manual.

[Junkers456]

If I were starting my project now I'd use the Cummins 2.8 crate motor. In fact, if I ever get mine going and am too unhappy with the Nissan motor I'll swap it.

Wish it were around when I started on this thing.

Heep, there've been threads on guys doing that but there's not a lot of room to spare under the dash either.

And then were back to the issue of affordability . Don't have an exact number on how much were willing to spend, but 9k for a motor is a bit much... I'm betting the max for a motor is 6k.

[Junkers456]

Junkers,

Idunno. I think I've seen more 6's than 4's on here and the other FSJ site.

For up front cost It would prolly be cheaper to use a current Chevy motor. They're like ***holes, every one's got em so they're relatively cheap and easy to find in junkyards. Or so I've heard. Never looked myself. Get relatively decent mileage with good power. And easier to fit.

Might even find one from a truck that has a trans and case. Might be hard to find a stick, though if that's what you want. And you prolly have to pay to have the computer messed with.

Trying to stay away from the computers junk. If I wasn't worried about computers, I would have had a Powerstroke being fit in already, but we don't want to deal with that garbage. Were going full mechanical if possible (like how the 6BT has close to one, maybe two wires coming off the block). It is an option, just not the preferred one. Thanks for the feedback!

[SJTD]

Junkers,

Idunno. I think I've seen more 6's than 4's on here and the other FSJ site.

For up front cost It would prolly be cheaper to use a current Chevy motor. They're like ***holes, every one's got em so they're relatively cheap and easy to find in junkyards. Or so I've heard. Never looked myself. Get relatively decent mileage with good power. And easier to fit.

Might even find one from a truck that has a trans and case. Might be hard to find a stick, though if that's what you want. And you prolly have to pay to have the computer messed with.

[SJTD]

If I were starting my project now I'd use the Cummins 2.8 crate motor. In fact, if I ever get mine going and am too unhappy with the Nissan motor I'll swap it.

Wish it were around when I started on this thing.

Heep, there've been threads on guys doing that but there's not a lot of room to spare under the dash either.

[Junkers456]

It depends on a lot of things!
How much do you want to spend and can you do all the work yourself!?

What kind of engine and drivetrain does your jeep have now?

I'm at the moment arranging parts and slowly starting on a rebuild and diesel conversion with my 73 J-4000.

It was my daily work truck for thirteen years and had a 360/T15/D20 with 4.10 axle ratio
The engine was converted for lpg.

I now have a low miles 12 valve Cummins and new nv4500 with rebuild np205 for it.
It also is going to roll on D60 front and D70 rear axles
With a utility bed on the back.

The reason I choose for a diesel engine with stronger drivetrain is durability and less maintenance.
It's not cheap and takes time to get the parts together.
But I really like to drive it and it's also the fun of building
And it's going to be my daily work truck again when it's complete and rolling.

I am quite positive my dad and I can do at least 99% of the work. Were both very competent with a welder, and we have all sorts of equipment and tools to do most, if not all, of the fab work. At the moment, the jeep has the 230 mated to a three speed. I don't even know what engine we would use if we were to do a swap. An OM606 would be awesome, but they are stupid expensive and very hard to find with a turbo, my great uncle has been quoted as saying the 6.2 and 6.5 did not have the question of if they would breakdown, but when, the 7.3 and 6.9 are really heavy and also becoming hard to find, and the 6BT is also really heavy and where I'm located, the cheapest you can find is 5k with 300,000 miles and a VERY questionable service history, and finally, the 4BT. EVERYONE is doing a 4BT, and I would like this to be at least somewhat unique... although, if we could find one, I wouldn't turn it down . Its going to be my daily, and I wont be doing much towing (if any at all), so having stupid amounts of power isn't the biggest issue. Just reliability, economy, etc. etc.

So my biggest question is this: is a gasser cheaper overall for my needs, or is a diesel the way to go?

[Heep-J4000]

Going to cut the opening in the firewall to make room enough for airflow and the mechanical fan can stay!

[SJTD]

I don't think it ever pays off. Even if you do it yourself. You do it because you want to and like Diesels.

The only way I'd put a 6BT in a Wag or J-truck is if I lengthened the front end. Frame, hood and fenders. I've seen enough of those conversions on here and other Jeep forums to think it's just too long.

But that's just my opinion. Worth what you payed for it.