om617A in j20

[nc wagoneer]

Okay, decided if I'm gonna have the j20 all the way down to the frame and engine anyways it's gonna be worth it in the long run. The flatbed won't fit in the garage so its coming off, front fenders and valance are coming off for rhinolining/color change and rust repair. Plus, I decided to get a different cab to replace my rusty and crusty one so that's coming off, so its down to the frame, motor, and axles. I've decided I'm going to work on the rust and sand down the frame and stuff to repaint it and most likely por-15 it, then its time for the drivetrain. Looking to go 4bt/5 speed (thinking nv4500) or maybe even a 6 speed What do you guys think about keeping the d20? I have a local machine shop that can make cheap adaptors for just about anything so it might cost $300 at most for the adaptor needed to mate the nv4500/d20. What's the easiest/cheapest mods for the 4bt to boost power? I DEFINITELY want to make sure its a turbo (don't wanna take a week making it to eci ) Ideas and thoughts please post below and anybody with experience please post up what's wrong with my idea

[nc wagoneer]

I've also considered the Isuzu 4bd motors and other 4cyl isuzus which are similar to the 4bt, but cheaper. Anybody know which of the Isuzu motors would be best?

[Mr. Goatman]

I have been looking for an Isuzu 4BD1-T for months and do not have one in hand yet (that I could afford) They stopped making then in the early 90s and they are becoming...eh... uncommon. If you find an extra let me know . At this time I'm considering a change to the 4BT because they are much easier to find. I'd probably keep the T-case that came behind the NV tranny- it's mated for capacity and no new adapters are needed.

[Resbum]

... Plus, I decided to get a different cab to replace my rusty and crusty one so that's coming off, so its down to the frame, motor, and axles.
... then its time for the drivetrain. Looking to go 4bt/5 speed (thinking nv4500) or maybe even a 6 speed
... it might cost $300 at most for the adaptor needed to mate the nv4500/d20.
...What's the easiest/cheapest mods for the 4bt to boost power? I DEFINITELY want to make sure its a turbo (don't wanna take a week making it to eci )
...Ideas and thoughts please post below and anybody with experience please post up what's wrong with my idea

.
I don't see anything wrong with your plan.

Here is the go to forum for anything 4BT swap related. I'll bet it just about answers any question you may have.
http://www.4btswaps.com/forum/forum.php

Also, any of the Cummins forums will have a ton of info. A lot of the 12V 6BT info is related to 4BT info in a general way. Just 2 more cylinders.

As for replacing the cab, when I decided to do that on my truck I hit craigslist. I found a donor truck and literally posted the engine, trans, and transfer case for sale on craigslist before I even picked it up for the seller. I then towed the truck to my buyers home and left it with him overnight so he could pull the parts. Between buying the truck and selling parts off it I made $50 before I even towed it home.

Looking forward to following your build.

Resbum

[nc wagoneer]

I'm actually camping out at Jake's full size jeep junkyard next weekend with a couple other members for a parts pulling trip, trading the waggy for a better cab and maybe more parts depending on what Jake and Jackie think old blues worth

[nc wagoneer]

Okay, maybe I have fooled myself. I've been looking at power figures for the mid 80's Mercedes om617 turbo straight 5's. Anybody have a link to a good source for 4bt power specs? I can get om617 donor cars with around 100-150k miles for 500-1000 around here and they are 500k+ motors. 120ish hp stock and 180tq. With a few cheap mods can reach near 150/200-210.

[jamesdart]

the 180 torque sounds kind of soft for a big truck.

[Mr. Goatman]

I looked into that and decided it was a little too small for my desires. I think it would work okay just not have a lot of power. However, they are great engines.

[nc wagoneer]

Okay, I've been thinking, om617/nv3550 and keep my Dana 20. Maybe step the 4.10's down to 4.56's?!?!? I'm thinking this might be what I need. Could probably run near 70, and can get +/-20 mpg

[jamesdart]

does the little diesel like to rev?

[nc wagoneer]

rev limiter is about 5500 rpm, so, I think it might just work out.

[nc wagoneer]

I think that since it puts out anywhere from 15-30 more lb ft of tq and hp than the Nissan sd33/sd33t it ought to work out okay, I mean, scouts and stuff were kinda doggish due to high gears with 3-4 speed transmissions. A newer trans, better gears, and a little bit more powerful engine might just work out. They put the ol617's in unimogs and g wagons all the time. the g wagons way about 5500lb, my j20 probably about the same as a waggy due to the steel flatbed so 4500-5000.

[AwesomeJ10]

I'm interested to see what you do as I've thought about a 4bt swap before...

[Nikkormat]

any updates?

[jaber]

He went another direction. Think he is or was selling the truck...

[nc wagoneer]

Idea was scrapped due to the need for a stronger trans and or divorced t case for the setup to work. I am looking to possibly sell or trade the truck for a Cherokee or wag

[carnuck]

200 ft lbs torque @2400 rpm so the AX-15 conversion for XJs would work. Get one for pre '90 and it has a .70 O/D (.75 after that) That will give you 70 mph cruise speed without redlining with 4.10 gears and 235/75/15 tires. NP208 is strong enough for that setup.