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4BT cummins drivability

original balzer

original balzer

1/2 ton status
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Does anyone know how a 4BT drives on the pavement? I have one found I can get fairly cheap.($1000) It was rebuilt a few years ago and in a tube chassis buggy that he claims its only run maybe 500 hours since he built it.

I just thought it might be a canidate to replace my 6.2 if it dies on me. So anyone run one in a street driven vehicle before?

Balzer
 
A friend of mine was running a 4bt in his 6k lb truck for a while. It worked fine and got good mileage ~25. However, he did find a 6bt later and swapped it in. Mainly due to the fact it wouldn't run very fast down the highway (gov to 2500) and lacked the total power for towing.

I believe the 4bt is 3.8L, might leave something to be desired, but is turboed. Is your 6.2 converted to turbo?
 
No its not turbo and the only thing I realy know about it is it runs. It has been swapped into a 79 truck so im sure its the engines second truck lol.
No idea how many miles or anything. It runs good, dont get me wrong, just not knowing anything about it makes me causious.

The 4BT is just available for fairly cheap, and just an opption to kick around.

Balzer
 
My G-pa dropped one in a '41 Power Wagon. He likes it, but he doesn't try to break land speed records either, and has 6.38 gears. Really depends on what you're doing with it on the street I suppose. A work and back rig would be fine if the gears are tall enough. Something to go get feed would probably be a better application though. Lacking a turbo will make it slow going on an on-ramp, but you can always mod a turbo onto it. Or a blower. Some sort of forced air.
 
I really can't imagine a non turbo 4bt being worth $1k. Not to mention how gutless it would be.

A buddy just picked up an entire bread truck (with running turbo 4bt) for $400 (and had the opportunity to purchase several more at the same price). I have seen many for sale in the $500 range.

I realize that this one's rebuilt but without the turbo I don't think its worth it. A non turbo 4bt would have substantially less power than your 6.2.
 
and being non turbo, you wouldent see the MPG increase mentioned earlier either, the turbo'd 4b 's arnt bad motors there a little lacking on power from the factory but a little work and just like the 6b's you have at least enough to tool around with.
 
LOL I figured the T in 4BT stood for turbo. This one is turbo chaged with a new garret something or other. It has a few mods done to it for a little more power, though I couldnt tell you what that means. I do know it has new injectors and I think he said the injector pump is new. I havent realy picked his brain about it until I asked yous guys whats up..

The confusion came from a question from BRENT72 asking if my 6.2 was turbo charged, and it isnt. The 4BT however is turbo. Im pretty sure the owner said it was a generator engine before he rebuilt it and put it in his buggy. By the way since im sure he isnt a member here, I have seen said buggy and its scarey. I think he built it from various scrap Iron as it has angle, square tube and round tube.
 
They make a little over 100 hp and ~300 ft. lbs. Lots of torque at low RPMs and a low redline.

You would need high gears, an adapter to get it to mate to a Chevy trans (unless it already has it, many 4bt's were in front of TH400s) and custom motor mounts etc.

Fixing the 6.2 in there now is probably the best and cheapest option IMO.
 
You know, after reading this a few more times, a conversation I had with my diesel mechanic buddy came to mind. We were talking about my Granddads rig. He said you could take the injectors for a 6b and throw them on there and get a nice power increase. Of course, a turbo is still needed. Yeah, the more I think about it, the more I'm with these guys. If it doesn't come with a turbo, it's not worth it if you can find the same engine with a turbo cheaper. It being freshly rebuilt might make it worth it to buy it, plus one with a turbo and just swap the turbo over though. I don't know enough about them to know the cost/benefit of that, but it's something the rest of these guys can answer.
 
In that case, drop in bigger injectors and let the black smoke roll... :D:D

They are saying that $1000 is a little high for that engine, but if that's a doable price for you, and you trust the fresh rebuild, I would call it fair game. Yes, you can buy that engine complete with bread truck for half the price, but how many miles/hours are on it? And of those miles, how many of them were made by a guy that didn't really care about the rig because it wasn't his?

Will the guy let you take it for a test ride in his buggy? In my mind 500 hrs in a rock buggy means less than 2000 miles. So, assuming that he didn't roll it and let it run upside down for too long, it should be in good order.
 
Yes, the "T" stands for turbo. If it doesn't have a turbo then it is a 4b. The 4bt is basically a 6bt with 2 cylinders chopped off. Most parts are swappable.

The problem is power. A 4bt is rated at about 130hp I think. If it has been worked on it may be worth $1000. Certainly is if it's putting out 200hp. Not so much if it's putting out 140hp;)

There is a forum out there strictly for swapping a Cummins into anything. I'd Google for it if I were you and find out exactly what to look for on this engine.

One thing to keep in mind. You may hear about 300hp 4bts. They are out there but cost $$$ and won't last.
 
I am no expert, but I don't think $1000 is high for that motor. Price them out on ebay, they go for alot more. I had read up a bunch on them awhile back, and they can be tweaked and tuned without a problem. IIRC you could find the adapter for a TH400 or a 4 speed from the bread trucks.

By the way, here is a site with some more tech and swap info for the 4bt.

www.4btswaps.com
 
IF you consider keeping the 6.2L, look on some of the GM diesel sites, I know there are ways to make them go. The only real question is cost, they are not cheap to build.

Ask around here on the board, some of our longtime members are still running them!
 
1. You will love a 4BT over your 6.2, much better bottom end and the engine will just feel stronger than the GM engine.

2. $1000 is basically cheap if it's in good shape. A P pump 12v 6BT is worth $4,000, just the engine.

3. If your 4BT happens to be a later model and has an inline pump..... grab it for sure. You can make that little 4BT turn 3,500RPM's and make 275+HP reliably. Combined with a good Dodge built auto, and you would suprise the heck out of a buddy with a blazer and a mild small block through an 1/8th mile.
 
I have seen it run, but the buggy has super low gears in the axles. He broke the buggy more often than he completed a trail (his words not mine) seams he had problems with rear springs and drivelines.

I realy dont have the fundage to buy it right now. I have spent alot on the crew cab already and just bought a 71 k10. Theres alot more I want to do b4 an engine swap. Just more of an idea for the future in case my 6.2 dies on me.
 
rjfguitar said:
A P pump 12v 6BT is worth $4,000, just the engine.
Click to expand...


Must be a Cali thing. Good running 6bt's can be found complete for around $2,000 to $2500 if you look hard enough. Junkyards sell them for $3,000 complete on places like junkyarddog.com
 
rjfguitar said:
1. You will love a 4BT over your 6.2, much better bottom end and the engine will just feel stronger than the GM engine.

2. $1000 is basically cheap if it's in good shape. A P pump 12v 6BT is worth $4,000, just the engine.

3. If your 4BT happens to be a later model and has an inline pump..... grab it for sure. You can make that little 4BT turn 3,500RPM's and make 275+HP reliably. Combined with a good Dodge built auto, and you would suprise the heck out of a buddy with a blazer and a mild small block through an 1/8th mile.
Click to expand...


Thats about what the owner told me, about liking it better than the 6.2. He said its pretty potent build. But as I said in my last post I just dont think its in the budget yet. I would rather focus my funds on getting a NV4500 and a doubler first, that way if I did go to a 4BT later it would have a nice drivetrain behind it.

I still think the tractor sound would be SWEET though.:bow:
 
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