4BT Cummins Diesel

[Reckless]

Has any one had any experence with the 3.9 liter 4BT cummins diesel. Its a 4 cyl turbo. They are found mostly in frito lay trucks and stuff. They have the same bolt pattern as a dodge cummins. Im wanting to find one for a replacement in my CJ-7. I know they are heavy but I want one reguardless. If some one knows where one is for cheap or any ideas, post them on here.

[Reckless]

Here is a page full of links on pirate for diesel conversions.
http://www.pirate4x4.com/forum/showthread.php?t=302523

[95discovery]

Im also kind of looking at those. I dont know what you consider cheap, but there was one on ebay last night with a 4-speed tranny for 3900 bucks. seems like a good price for a running diesel, especially with a trans. If you get one let me know how it is

[Reckless]

I saw that same one today. All the 4BT is a 5.9 dodge w/ 2 cyl cut off. If you can find an old frito lay truck for sale, thats the ticket. Frito lay sells them for around a grand or 2 when they retire em so i hear they are easy to find then you can sell the truck body for scrap.

[Sharpe]

I would not put a 750 pound engine in a jeep. They are smaller than a 6 cylinder yes but they are still ****ing huge. If I ever get my hands on one, its getting a few mods and going in the crewcab.

[73bronco]

there are several guys who've put them im eb's so i say if you can find one cheap do it

[CheapJeep]

Seems cool, but like Robert said, lots of weight. Hmmm, 5.3 from truck to Jeep, Cummins to truck??? :laughing: :rolleyes:

[robertf03]

gay

tdi would be better for rover

[agjohn02]

high rpm horsepower is where its at for offroading

[95discovery]

gay

tdi would be better for rover

if i got one (which is a very big if) it wouldnt be going in the rover...

[robertf03]

what else would you want to put it in? 60 - 62 buick special?

[95discovery]

how about an 83 wagoneer? for now im just gonna stick with the 360 or may even swap in a 350 thats just sitting in the garage. But eventually a diesel would be sweet in that thing.

[Reckless]

Right now i just want one in the Cj for the mileage and i can run cheap farm diesel at home. 750 lbs for the diesel vs 700 for a bigblock and 2x the milage its not that bad and i can work on the damn thing too.

[Reckless]

On the cummins racing page i posted on the racing video forum, on the 4th segment of the DHRA 05 race videos, there is a YJ repowered with the 4bt twin turboed and the guy does it real clean.

[bburris]

I would not put a 750 pound engine in a jeep.
Yeah, who would do a dumb thing like that...

[Sharpe]

Its cool if you buy said 750 pound engine from me. Otherwise, dont do it.

[fbronco86]

Right now i just want one in the Cj for the mileage and i can run cheap farm diesel at home. 750 lbs for the diesel vs 700 for a bigblock and 2x the milage its not that bad and i can work on the damn thing too.

Get a Honda if you want good milage. :gigem:

[Reckless]

30+ mpg estimated

[sasquatch]

sounds like more trouble than its worth

[Reckless]

I could even run Bio diesel so i will be treading lightly for the hippies.

[Graystroke]

if you put a 4bt in a your heap you will have to locktite every nut an bolt. not the smoothest running engine. power band is narrow so you would have to change up the gearing as well. Mercedes diesel is where it is at. I can rap 4500 rpm on mine runs 3000 rpm at 75mph all day and gets 30 mpg. burns no oil, is quiet, and smooth. mine has 280,000 mi and runs like a champ. mine is rated at 140hp and 200ft/lb.

[Reckless]

but cummins parts are half of what the mercedes diesels are and are easer to obtain parts.

[jerryg79]

but cummins parts are half of what the mercedes diesels are and are easer to obtain parts.

never under any circumstances play the money card when arguing with grayson....you always got ripped off :flipoff2:

[sasquatch]

what are you replaceing? a 4.2? try getting a amc 304 which will probably bolt up to what you have. they have plenty of low end power. and why are you worried about mileage when you going to be wheeling? or is this going to stay on the road

[Reckless]

both

[CheapJeep]

Get a 360, it's still an AMC so it'd be a direct bolt in plus the 304 has the heads that everybody tries to upgrade but has to pay big$$ to do so.

[tigweld]

They are found mostly in frito lay trucks and stuff. They have the same bolt pattern as a dodge cummins.

The ones I have seen either had a th-400 or a np465 behind'em (maybe cause they were in chebby box vans), but I couldn't tell if there was a adapter. I thought the the 4bt had a SAE pattern(don't remember which one) due to it being used in many different industrial apps.

[eight]

may even swap in a 350 thats just sitting in the garage.

This would be a dumb idea.

[95discovery]

whys that

[Reckless]

The ones I have seen either had a th-400 or a np465 behind'em (maybe cause they were in chebby box vans), but I couldn't tell if there was a adapter. I thought the the 4bt had a SAE pattern(don't remember which one) due to it being used in many different industrial apps.

It depends on what application it was used in, like you said, they had the TH400 and the 465, but the ones ive worked on had the round cummins bolt pattern.

[eight]

whys that

The AMC's a much better engine than your stardard old SBC. Better heads, stronger bottom end, bigger lifters, stronger block. It was designed after everyone else's small blocks had been out a long time. They took what was good from all the others and combined them, and it came out closer to a chrysler than anything else. If you want to go chevy, it needs to be of the LT1 or LS series.

[Sharpe]

The 4bt cummins has the same tranny bolt pattern as a 6bt. They are mated to GM tansmissions using an adapter plate made by cummins. This plate sells for about $700 used if you can find one. One thing alot of people dont like about the plate is that with the 6bt, it tilts the engine about 5 degrees to one side. Why, I dont know. I also dont know if it has the same effect on 4bt's but they are the ones that came with it from the factory.

Put a 6.5L chevy diesel with a banks turbo kit in the jeep. You get good power and mileage and alot less cost. In fact, I know someone that is selling one.

[95discovery]

The AMC's a much better engine than your stardard old SBC. Better heads, stronger bottom end, bigger lifters, stronger block. It was designed after everyone else's small blocks had been out a long time. They took what was good from all the others and combined them, and it came out closer to a chrysler than anything else. If you want to go chevy, it needs to be of the LT1 or LS series.

thanks, i dont really know too much about that engine. The only thing ive noticed is that parts are much easier to come by for the sbc than for the 360 but i may just not be looking in the right places.

[Reckless]

The 4bt cummins has the same tranny bolt pattern as a 6bt. They are mated to GM tansmissions using an adapter plate made by cummins. This plate sells for about $700 used if you can find one. One thing alot of people dont like about the plate is that with the 6bt, it tilts the engine about 5 degrees to one side. Why, I dont know. I also dont know if it has the same effect on 4bt's but they are the ones that came with it from the factory.

Put a 6.5L chevy diesel with a banks turbo kit in the jeep. You get good power and mileage and alot less cost. In fact, I know someone that is selling one.

The 4bt has the same problem with the 5degree plate but they just make the tranny tilted in the conversions ive seen.

I think pig pen needs the motor more than i do. :flipoff2:

[fbronco86]

I would put a 7.3l in it. Best motor ever.

[Sharpe]

If I got my hands on a 4bt I'd probably sell it and do some mod to pigpen to double its value.

[jerryg79]

If I got my hands on a 4bt I'd probably sell it and do some mod to pigpen to double its value.

replace the bulb in the ash tray lamp? :flipoff2:

[uglyota]

buy acetylene and convert it into "short metal"
(good game, Jerry!)

[eight]

Yea there are less suppliers but anything you want is available. They just don't list many of them in the jegs and summit catalogs.


thanks, i dont really know too much about that engine. The only thing ive noticed is that parts are much easier to come by for the sbc than for the 360 but i may just not be looking in the right places.

[BMFScout]

Yea there are less suppliers but anything you want is available. They just don't list many of them in the jegs and summit catalogs.

BYOVaseline

[agjohn02]

The AMC's a much better engine than your stardard old SBC. Better heads, stronger bottom end, bigger lifters, stronger block. It was designed after everyone else's small blocks had been out a long time. They took what was good from all the others and combined them, and it came out closer to a chrysler than anything else. If you want to go chevy, it needs to be of the LT1 or LS series.


yeah, just look in any hotrod mag and you can see where all the power is coming from. nobody runs smallblocks with aluminum heads and aftermarket parts anmore. all the cool kids run stock amc 360's. why, i was having lunch with zora arkus-duntov and dale earnhardt sr. last week and they both said they are switching to amc 360's this year...er something.

[eight]

Yea the aftermarket has figured out to make a SBC work well.

[robertf03]

yeah, just look in any hotrod mag and you can see where all the power is coming from. nobody runs smallblocks with aluminum heads and aftermarket parts anmore. all the cool kids run stock amc 360's. why, i was having lunch with zora arkus-duntov and dale earnhardt sr. last week and they both said they are switching to amc 360's this year...er something.

I wonder how many of those people are running stock shortblocks......

[Graystroke]

The AMC's a much better engine than your stardard old SBC. Better heads, stronger bottom end, bigger lifters, stronger block. It was designed after everyone else's small blocks had been out a long time. They took what was good from all the others and combined them, and it came out closer to a chrysler than anything else. If you want to go chevy, it needs to be of the LT1 or LS series.
why would not just swap in a 4.6 w/ a cam and some head work and be done w/ it..plus you save 300lbs

[robertf03]

why would not just swap in a 4.6 w/ a cam and some head work and be done w/ it..plus you save 300lbs

Been trying to tell you to do that instead of satisfying your diesel fetish on the series truck

[eight]

A 4.6 is wider than a big block, it doesn't fit between jeep fenderwells. And it uses 4 cams which end up being really expensive to replace. But it has a nice stong bottom end, good enough that chevy copied it in the LS series. I thought the modification for these was to blow more air into it.

[robertf03]

A 4.6 is wider than a big block, it doesn't fit between jeep fenderwells. And it uses 4 cams which end up being really expensive to replace. But it has a nice stong bottom end, good enough that chevy copied it in the LS series. I thought the modification for these was to blow more air into it.

think buick/leyland/rover, not ford

[Reckless]

ok its getting off subject but keep it to the original thread idea.

[eight]

OK the 3.9 is too heavy, expensive, and a 4 cylinder.

Get a 6.5 with a manual pump.

[95discovery]

OK the 3.9 is too heavy, expensive, and a 4 cylinder.

Get a 6.5 with a manual pump.

which 3.9 is a 4 cyl?

edit: nevermind im an idiot

[AggieTJ2007]

what did you expect...TAMOR is a forum with ADD

[Sharpe]

OK the 3.9 is too heavy, expensive, and a 4 cylinder.

Get a 6.5 with a manual pump.
Hell yah. Thats the spirit!

[Reckless]

I talked with my instructor today and he said that I could add twin Turbos and play with the valve and injection timing and push upwards of estimated 250Hp and 450 torque (same if not more than the 6.5) and still get around 30mpg.

[uglyota]

what did your instructor say about the vibration issue?

[AggieTJ2007]

theres a catch there, you get 30mpg when not using the power, if your using the power, no 30mpg

[Reckless]

He said on the vibration shouldnt be that bad, bout as bad as a dodge one, i can buy some better isolators for the mounts and then bout as much vib as a SBC.

[AgDieseler]

It's a cool motor, but don't think it's a practical swap. Do it for the cool factor, and don't try to justify it any other way. Cool is valid.

[Graystroke]

He said on the vibration shouldnt be that bad, bout as bad as a dodge one, i can buy some better isolators for the mounts and then bout as much vib as a SBC.
your instructor is not very smart. a 4 cylinder would be noticebly rougher than a six...hence a balance shaft on most 4 cyl. the 4bt was originally designed for industrial stationary use. cummins didn't give a **** when their 4bt was vibrating away while pumping water into an irrigation ditch in the middle of a field. a friend of mine use to have quite a few on his ranch and said they ran forever but you had to take a tool set around to all of them and tighten loose bolts.
did your instructor forget that straight six cylinders are naturally balanced b/c of their firing order?
why do you think v-12's are so smooth

[Reckless]

I know what you mean by the vibrations but those can be isolated with better mounts and other mods that wouldnt be that expensive. If you play with the injection timing, you can bring down the vibrations, thats why the duramaxes are so quiet and smooth, because of the timing and duration of injection. So if i play with the timing and duration the vibs wont be as bad. We have 3 of them in the shop and none are as bad as one would think. And yes the cool factor is one of the players in this eventual swap!

[eight]

If you retard the timing to smooth it you'll loose power, mileage, and get higher EGTs.

[Graystroke]

duramax is different breed from a mechanical cummins 4bt. duramax's are common rail and run electronic injectors that can be held open at different intervals/durations. 4bt's timing is linear in that it is fixed and uses mechanically timed injections of fuel and a poppet style mechanical injector. can't compare the two except that they both use diesel fuel.

[uglyota]

Do it for the cool factor, and don't try to justify it any other way. Cool is valid.
bingo

[BMFScout]

I don't believe you could make a cummins whatever run as smooth as a SBC. If you can, you are not very good at tuning the SBC...

[Sharpe]

I don't believe you could make a cummins whatever run as smooth as a SBC. If you can, you are not very good at tuning the SBC...
Agreed. I have been around enough 6bt's to draw the conclusion that they are noisy and vibrate more than any tuned gasser I've seen. The 6.2 in pigpen vibrates more though but it has poly spring bushing motor mounts.

[uglyota]

http://autos.groups.yahoo.com/group/cummins4BT/

[AgDieseler]

...The 6.2 in pigpen vibrates more though but it has poly spring bushing motor mounts.
More fuel and boost will smooth out that little guy. :gigem:

[Sharpe]

Smartass. I still think it has a cylinder with low compression. Is it possible for the compression to be low enough in one cylinder where it doesnt fire at idle but it does when you give it just a little bit of skinny pedal? Cause pigpens mota vibrates REALLY bad at idle but smooths out perfectly above idle.

[uglyota]

Hey if you're still trying to find one of these, there is what looks to be an old frito-lay truck for sale out on Merka Road south of the winery.

[Doug Krebs]

Hey if you're still trying to find one of these, there is what looks to be an old frito-lay truck for sale out on Merka Road south of the winery.

I'll be back in a few minutes...

[jerryg79]

so, twats the story?

[Doug Krebs]

so, twats the story?

eric's a liar and made me burn a $1 or 2$ worth of gas... I think he got the wrong street.

[uglyota]

well I saw Merka road on the same bike ride that I saw the truck...

$20 and I tell you the right one :flipoff2:

[jerryg79]

twat a doosh :flipoff2:

[CheapJeep]

twat a doosh :flipoff2:
:laughing:

[Doug Krebs]

so after jamming the cell phone in my helmet and trying to get voice guided directions by eric I never found it on Merka. However on my way home I took a different route and cruised right by the thing on Old reliance road.

Too bad it's a 350. It did have a kick ass kitchen in it though.

There is a old IH pickup right next to it with a full floating axle if anyone is interested.

[DRAGOONRANCH]

so you found the roach coach and the plow puller.

[jerryg79]

so after jamming the cell phone in my helmet and trying to get voice guided directions by eric I never found it on Merka. However on my way home I took a different route and cruised right by the thing on Old reliance road.

Too bad it's a 350. It did have a kick ass kitchen in it though.

There is a old IH pickup right next to it with a full floating axle if anyone is interested.

Is it a harvester, if so I'm interested.

That one never gets old :flipoff2:

[agjohn02]

Is it a harvester, if so I'm interested.

That one never gets old :flipoff2:


it must be, he said IH. not just I.

[Sharpe]

Fags

[Reckless]

In the new Diesel Power mag, my conversion that i want is featured in it. But its in a yj, but the fuel and other stuff i was talking about is verified.

[uglyota]

you confirmed that the 4bt does in fact use diesel fuel?

:flipoff2:

[Reckless]

i ment the mileage

[uglyota]

jus playin :)

[DRAGOONRANCH]

Here's a thread that just showed up on pbb. Looks like it may end up being useful, atleast till the pbb hacks get ahold of it. :flipoff2: