Can't Find a Cummins 3.3L

[Boze]

I read an article about a guy who swapped a Cummins B33 into his YJ and was getting over 35 MPG with his original AX-15 and 33" tires. I really like the sound of that, but I can't find the engine anywhere online. I can find the older B39 for around 3,300 new, but I want the smaller, lighter 3.3L. Does anyone know where a guy could find one of these either re-built or new? Thanks guys.

-Boze

 

[jps4jeep]

why not a 4bt from a delivery van? my understanding, more support both factory and aftermarket and it is a proven swap into a jeep.

 

[Ggg]

jps4jeep the 4bt is the B3.9 he was talking about that he could find for around $3,300.

 

[Ggg]

Boze I don't think that engine can legally be swapped into a road vehicle. It is a stationary power plant. It only puts out a max of 85 hp/ 215 ft.lb., and thats before any parasitic losses from alternator, fan, or other accessory items. It weighs about #550.

 

[Wrangl3r93]

I have a friend with the 4bt who is getting 35mpg if he keeps it at 55mph. It drops to 30mpg at 70mph, but that's def a major improvement over stock.

 

[jps4jeep]

jps4jeep the 4bt is the B3.9 he was talking about that he could find for around $3,300.

Ya I knew that, I have reading issues

My suggestion for a cheap diesel would be search for a mercedes from the mid 80's. While I have not personally seen one in a jeep, I was planning to do the swap... But I have an associate who put one in a rover. unfortunatly it is not yet running so I can't offer fuel milage feedback or ease of install.

 

[Boze]

I thought there was a 3.3 Turbo that put out more hp. Maybe I'm wrong. I know the 3.3 isn't intended for street apps. but I'm a resident of Oregon so I don't have to smog my rig. I could for all intents and purposes put a top fuel drag motor in there and be legal...but that would just be showing off. :lol:

Johnny's right though, there is just way more support for the B39. I think it's probably the way to go. Here's what I found out about the B39:


The 3.9L/4BT Cummins is an engine in the same family as the 5.9L Cummins turbodiesels. The 3.9L/4B is an inline four-cylinder turbodiesel that was popular for many step van applications including bread vans and other commercial vehicles. This engine is also used in various industrial and construction applications. With a cylinder bore of 4.02 inches (102 mm) and a piston stroke of 4.72 inches (120 mm), the engine had a wet weight of 745 pounds (338 kg). In recent years it produced 130 hp (97 kW) and 355 lb·ft (481 N·m) of torque. The 4BT today is also popular as a conversion engine among many light-duty pickup trucks that were originally equipped with gasoline engines. This is due to its high fuel efficiency while producing power comparable to the original light-duty gasoline engine.

745Lbs?!!!! That's 215Lbs more than the 4.0! So you would have to beef up the front springs a bit I guess. But I've been weighing the pros and cons and I think it's worth it for that 25+mpg and 350 lbs/ft. I wonder what transmission I would have to use, or if the ax15 could handle it with maybe a beefed up clutch. I'm really thinking this might just be a worth while undertaking.

Here's some pictures, (had to steal them from another site). iratenanner:

 

[Boze]

whoops...

 

[Ggg]

Boze I have a 4bt in my TJ but it is not running yet. I am running D60/ Sterling 10.25 axles, AX15/231, 38.5" tires, 6" lift. The AX15/231 will handle the power even in moderate wheeling. The torque it makes is up in the big block gasser range, so power application finesse is the key. Don't worry about the clutch as the Jeep clutch and flywheel do not mate to the engine. You will need a Cummins flywheel which uses a 12" clutch so that is plenty big, and an adapter to mate the AX15 to a GM bellhousing. If I were starting all over I would buy an engine, flywheel housing and flywheel from a GM manual trans application. A Ford manual trans aplication will work as well. The GM auto trans application is most common but the most costly to adapt to an AX15. A Cummins to GM flywheel new is close to a grand.
There is a good site that specializes in 4bt swaps I am Ggg over there too.
Cummins 4BT & Diesel Conversions Forums - Powered by vBulletin
Search there a lot of us have done Jeep swaps. Some say the AX15 is too weak but a friend of mine rock crawks with a Cummins/AX15 combo and absolutely no issues. Also since you are from OR look up Northwest Bombers they are a good Cummins group albeit mostly 6bt.
The pics you posted look very similar to my TJ. Where did you find them.
There are plenty of other engines that would make a good swap such as MB, VW, Isuzu, Perkins, LP, Detroit, Deutz, etc. all have their pros and cons.

 

[Crazy4diesels]

Woah, that's a lot of iron under that little hood:shades:. The 4BT is a great little engine but watch the torque. You will need to upgrade your driveline otherwise your Jeep will produce interesting scrap metal now and then. None of the stock parts will survive the wrath of a 4BT. The 6BT has been grenading truck drivelines for over twenty years now. As JPS said there are some smaller diesels out there too. If you get the 4B to work out you'll have an awsome Jeep. With proper care those engines run almost forever (a milion miles is possible). Best of luck and keep us posted!! - John

 

[drivers]

i read a artical in a jeeppin mag about a guy who put a 3.9 into his YJ, cant remeber the year but he went from the supercharged 6 to the 3.9 he passed smogg in cali, i dont have to worrie about the smogg as much but i do like the 35mpg

 

[Ggg]

My TJ has been running and driving for about the last 5 months now. I am a member on 4btswaps.com since its beginning and have seen a lot of write ups on Cummins into a Jeep, I honestly would say 35mpg is a pipe dream. Realistically low to mid 20's is what I say to expect. Several have had quite an issue just getting to 20 mpg on a regular basis.

 

[myjeepdestroys]

I would recomment the new super turbo. Duramax 6.6l turbo and supercharged.

 

[Ggg]

That would be quite a logistical pita getting the LML Duramax to work, or most any of the computerized diesels. Not saying it isn't possible, just a lot of headaches.

 

[Boze]

Wow, After going back and reading that string...I was maybe a bit "big for my britches" haha. I would still like to do the 4bt swap, but I just don't have the money for something that extreme right now. I have, however, been looking into the NOVAK kits for dropping a GM small block in my Jeep, (there are literally people giving them away on Craig's list all the time). I could get into something like that for around 2k if I did it smart. Hmmm....the hamster wheel continues to turn for now.

 

[Ggg]

I have had some unfavorable dealings with Novak when it came to my 4bt swap. I honestly can't recommend them with a good conscious.
But I agree a SBC or other more common engine can easily be done for less money than a 4bt swap. I happen to like diesels a lot so that's the way I went.

 

[drivers]

from all the reaserch i have done i would go with a 3.9 cummins over a 3.3 if you plan on doing a 4bt swap the 3.3 was desinged as a power plant for industrial use as was the 3.9 but the 3.9 was also used in automotive uses like in delivery trucks and what not usually put with a GM 3spd auto with it
thats just what i have found out

 

[drivers]

lol and if i would have read further everything that i have said has been told already
cheers guys lol