Looking for any info on the Cummins 4bt? Forums, news groups, people who've swapped them, etc. I'm also looking for videos of them in action. So if anybody has some info please share it.

 

The 3.9 4BT is about the same as our 5.9 6BT(12 valve) or ISB(24 valve). Only difference is its missing 2 cylinders. Exact same bore and stroke as the 6. And since its 2/3rds the engine it has 2/3rds the power of the 6.

Example: a 01 ISB has 235 HP and 460 torque. The 4BT would have 156 HP and 305 torque.

A common source for the 4BT are bread and chip delivery trucks (think Frito Lay). Those delivery trucks frequently came with a Chevy automatic (4L85 I believe).

 

i looked at a couple and they had turbo 400's,they use a special pan that extends up under the converter,kinda combo pan flywheel cover.

 

Well I know the common specs on the 4bt but heres the delima, I'm thinking of running one of these in my 1500 dodge 4x4. My 360 is alright but the lack of gas mileage and hell diesel is hassle free for the most part, I thought about swapping out for a bombed 4bt... so anybody have some real world experience in these engines? My main questions are,
-how does it pull?
-I hear redline is 2400 or so?
-Can I raise it up to 3k like the 6bt and not have it rattle itself to death?
-Is it possible to pass people with this engine?
-Any real videos of a 4bt running?
-Lastly I read somewhere that 1500 dodge still have the bolt holes to line up a 6bt, would that mean a 4bt would practically drop in?

 

I knew it was one of them GM trannies.

Lockdown - Yes they are BOMBable. They will take any of the mods that we can use on our 6. Injectors (only need 4), turbo, fuel pump tweaks. I would check for the wieght. it might be borderline in a 1500.

 

well I know the 6bt is much to heavy but I was told a 4bt is just fine, a couple hundred pounds heavier. My numbers aren't exact but my 360 is 500 lbs and a 4bt is 700lbs... i believe. If anybody can correct me please do. Also people are putting 4bts in Jeeps and such, I figure my 1500 could take it.

EDIT: heres the jeep with the 4bt
http://www.burnsvilleoffroad.com/04_05.html

 

HEY LOCKDOWN!, Where you gettin your information from?? Who-ever HE is, he must be ONE FART SMELLER!! or, a, I mean SMART FELLER!!lol www.burnsvilleoffroad.com

 

i went with the 6 2 years ago and aint looked back. short trip driving 18 plus for 2 years. no cracks in frame. stronger springs and shocks. core support is the real problem. dang it look at front axle gross weight it will handle the weight. it wont be a road course truck but a great daily driver. low 5s 0 to 60 and great mileage. ps i went for power and not mileage and look what i got.

 

i'm lost here?

Jughead ya I asked about the 6bt in a 1500 frame but everybody just about shot me. That and a 6bt is mucho expensive compared to the 4bt and I think I would rather stick to somthing near the same weight as my 360. I'm not pulling anything ever, I want it for gas mileage, realiablity, power (much better than any gasser), the sound, and for the smoke stories!

EDIT: One more thing jughead I have a 96 4x4 Reg Cab shortbed which would really upset my weight balance with a 6bt. God I could see the understeer coming a mile away heh. Also one more question on your 1500 did it the 6bt just drop in?

 

I gave you that info over at pavement sucks. HELLO!!

 

Doh, sorry I don't pay attention to names much hehe. Oh so sorry, Doodah gave me that information.

 

not a drop in but one of the easiest swaps i have ever done. 90 mounts fit frame holes. had to slot the holes for radiator room. hard part was reworking the core support for larger radiator. would have been easy for body man which i aint. it is not a road course truck but it handles as good as my 90ctd 4/4. i dont know why EVERYONE says it will break the frame on a half ton. i am still under gross axle weight. if something breaks in front end this board will be the first to know. 9.25 rear handles 9" slicks with no problems

 

Jughead appreciate your info. So to make me perfectly clear that the 1990 motor mounts for the 6bt line up with what year 1500 (I have a 96)??

Also i'm thinking of going 4bt because of the weight for one two I do absolutly zero towing just want hte gas milage and mudding power.

 

i used 97 ctd, 90 mounts complete assembly. 82 dodge 1/2 ton with 318 engine.

 

Here are two links to sites that belong to a couple of guys that swapped 4BTs into older Dodges. You can e-mail either or both of them and ask for help, they are both REALLY great guys and like to share info!


Paul's WWII WC53 Carryall with 4BT conversion.
http://imageevent.com/moosecreekmaple/1943dodgecarryall

Cabell's M37 with 4BT conversion. (Info in links on left hand side of the page)
http://www.garbee.net/%7Ecabell/

Good luck!