PDA

View Full Version : chevy cummins conversion question



rvdjr
03-10-2008, 16:38
i saw an ad on ebay for a cummins 4BT 3.9 that was attached to a 400 turbo transmission. it was removed from some commercial vehicle. the seller told me there was a factory adapter plate that allowed the bell housing to bolt up and that the driven part of the tranny bolted directly to the engine without modification.

question 1: does anyone know if the engine is an ordinary cummins engine or a special production engine?

question 2: what about the 400 turbo tranny? is it special or just an ordinary 400 turbo?

question 3: if there are no special circumstances with the engine and tranny, where can i get the adapter plate? (easily, from someone who knows what it is and how to find it)

question 4: we have two older farm vehicles we would like to convert to diesel, a 90 chevy 3/4 4x4 and a 77 cj7. with both vehicles being 4x4 it has been impossible to find an engine/tranny set. we would like to use a mechanical set up (no computer), and would like to avoid the older ford and chevy diesel pick up engines. does anyone know which industrial diesels will bolt to chevy and chrysler transmissions? we would like at least 80 hp for the jeep and at least 150hp for the truck.

i know ive asked for alot so thanks in advance. if you dont have any info but do know where i can find it please let me know.

wthif
03-10-2008, 21:24
Go to 4btswaps.com (http://www.4btswaps.com) and have a look around. All of your questions should be answered rather quickly.

rvdjr
03-11-2008, 09:38
thanks for the link. there is so much info but it is hard to find specifics. but one of my questions was answered well. the th400 that was put behind the cummins from the factory is different. it has different valve body, torque converter, and pan. but so far i havent found a part number for the diesel th400, which would be helpful if i wanted to convert standard th400 to the diesel configuration. otherwise i will need to purchase the diesel model and a standard model 4x4 and convert the diesel to 4x4.

another piece of info i failed to find is a list of vehicles that used cummins engines from the factory. if i just knew the vehicle models i could find the part numbers that i would need.

if anyone runs across a useful link please post it.

here is the most useful link i ran across:FAQ: 4BT Swaps Topic Index - Cummins 4BT Forums (http://www.4btswaps.com/forum/showthread.php?t=1076)

rvdjr
03-13-2008, 16:38
http://www.dieseltruckresource.com/dev/showthread.php?t=112807

these guys are using the cummins B3.3 instead of the 4BT. the 3.3 weighs 200 pounds less than the 4BT (just slightly more than the jeep 4.2)

it is a long thread, but very interesting to read

Burning Oil
03-20-2008, 19:22
i saw an ad on ebay for a cummins 4BT 3.9 that was attached to a 400 turbo transmission. it was removed from some commercial vehicle. the seller told me there was a factory adapter plate that allowed the bell housing to bolt up and that the driven part of the tranny bolted directly to the engine without modification.

question 1: does anyone know if the engine is an ordinary cummins engine or a special production engine?

question 2: what about the 400 turbo tranny? is it special or just an ordinary 400 turbo?

question 3: if there are no special circumstances with the engine and tranny, where can i get the adapter plate? (easily, from someone who knows what it is and how to find it)

question 4: we have two older farm vehicles we would like to convert to diesel, a 90 chevy 3/4 4x4 and a 77 cj7. with both vehicles being 4x4 it has been impossible to find an engine/tranny set. we would like to use a mechanical set up (no computer), and would like to avoid the older ford and chevy diesel pick up engines. does anyone know which industrial diesels will bolt to chevy and chrysler transmissions? we would like at least 80 hp for the jeep and at least 150hp for the truck.

i know ive asked for alot so thanks in advance. if you dont have any info but do know where i can find it please let me know.

With the GM adapter like you are refering to you can basicaly bolt up any GM trans to the adapter. Mine would even allow a Buick, Olds and Pontiac trans. Manual or auto will work.
I have a 4L80E behind my Dodge 6BT with the bread truck adapter. It works great.
The trans behind the Cummins in the bread trucks are special, but any other GM trans will bolt up inplace of it.
The engine is just a 4 series Cummins Nothing special. It is kind of like a Chevy 4.3 v6 is to a 350. All the bolt hole dimentions on a 4bt or a 6bt are the same.
I see the adapter plates all the time on ebay and one seller is selling a billet adapter and flywheel for $1400. The bread truck versions are $750 and up.

BTW my truck is for sale on ebay right now search GMC CUMMINS its a blue 1996 CC 4x4 dually

rvdjr
03-24-2008, 18:34
With the GM adapter like you are refering to you can basicaly bolt up any GM trans to the adapter. Mine would even allow a Buick, Olds and Pontiac trans. Manual or auto will work.
I have a 4L80E behind my Dodge 6BT with the bread truck adapter. It works great.
The trans behind the Cummins in the bread trucks are special, but any other GM trans will bolt up inplace of it.
The engine is just a 4 series Cummins Nothing special. It is kind of like a Chevy 4.3 v6 is to a 350. All the bolt hole dimentions on a 4bt or a 6bt are the same.
I see the adapter plates all the time on ebay and one seller is selling a billet adapter and flywheel for $1400. The bread truck versions are $750 and up.

BTW my truck is for sale on ebay right now search GMC CUMMINS its a blue 1996 CC 4x4 dually

when you say that "it bolts right up to any gm tranny", what about the clutch, pressure plate, and fly wheel? will i need any "special" pieces other than the cummins/chevy bell housing?

does anyone know about the b3.3's? the guys on the link i provided earlier pointed out that the b3.3 weighs about the same as a small block V8 or an inline 6. this really has me considering a 3.3. does the 3.3 have the same back end as a 3.9?

Burning Oil
03-24-2008, 21:00
when you say that "it bolts right up to any gm tranny", what about the clutch, pressure plate, and fly wheel? will i need any "special" pieces other than the cummins/chevy bell housing?

does anyone know about the b3.3's? the guys on the link i provided earlier pointed out that the b3.3 weighs about the same as a small block V8 or an inline 6. this really has me considering a 3.3. does the 3.3 have the same back end as a 3.9?

Well, the clutch is inside the bell housing and the bell housing bolts to the adapter so it will work fine, make sure to get the crank "hub" spacer thing.
The adapter is not a bell housing. You will use the housing that comes with your trans.
I don't know anything about the 3.3

rvdjr
03-25-2008, 16:09
Well, the clutch is inside the bell housing and the bell housing bolts to the adapter so it will work fine, make sure to get the crank "hub" spacer thing.
The adapter is not a bell housing. You will use the housing that comes with your trans.
I don't know anything about the 3.3
what about the extra length from the adapter? are there any issues with the length of the tranny input shaft? will i have to have a thicker flywheel to compensate for the thickness of the adapter?

i tried searching on ebay but didnt find anything. what should i put in the search box? the prices you listed scared me! how much do the normal used ones go for?

Burning Oil
03-25-2008, 17:20
what about the extra length from the adapter? are there any issues with the length of the tranny input shaft? will i have to have a thicker flywheel to compensate for the thickness of the adapter?

i tried searching on ebay but didnt find anything. what should i put in the search box? the prices you listed scared me! how much do the normal used ones go for?

As long as you get all the parts that go with the adapter for a manual trans you will be fine. The crank Hub will give you the proper spacing. Actually I think all you need is the adapter and hub and I think one for an auto should work also. Your flywheel will bolt to it. One thing to make sure of is if your flywheel bolt patern is the same as the crank hub. I have one I can measure if you need.

rvdjr
03-25-2008, 19:03
As long as you get all the parts that go with the adapter for a manual trans you will be fine. The crank Hub will give you the proper spacing. Actually I think all you need is the adapter and hub and I think one for an auto should work also. Your flywheel will bolt to it. One thing to make sure of is if your flywheel bolt patern is the same as the crank hub. I have one I can measure if you need.
at this point all my stuff is still bolted together so a measurement isnt needed at this time, but thanks anyway. i finally found the expensive adapters on ebay but still havent run across one of the used factory adapters.

Burning Oil
03-29-2008, 11:21
at this point all my stuff is still bolted together so a measurement isnt needed at this time, but thanks anyway. i finally found the expensive adapters on ebay but still havent run across one of the used factory adapters.

http://cgi.ebay.com/ebaymotors/Cummins-4BT-to-Chevy-GM-GMC-700R4-4L80E-TH400-Adapter_W0QQcmdZViewItemQQcategoryZ33727QQihZ001QQ itemZ110238240290QQrdZ1QQsspagenameZWDVW

Good luck