Login    Forum    FAQ

Board index » 4x4 Related Technical Forums » Misc 4x4 Tech




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: Cummins 6BT Questions
 Post Posted: Sun Aug 10, 2008 8:54 pm 
Offline
Killed his Hooptie Geo Prism
User avatar

Joined: Mon May 08, 2006 8:49 pm
Posts: 202
Location: Fort Wayne, IN
I have an opportunity to be given (as in FREE...I like FREE) a 1991 Cummins 6BT.
It has a 330K miles, runs but smokes like a freight train and is low on power.

The owner is installing a Cummins 4BT into a 1977 Ramcharger.
So, the donor, a 1991 Dodge Ram 3500 is giving up its axles, 727, 205, cross member, engine adapter and flexplate, all linkages, and any other accessories that might be compatible.
Which leaves me a with a running core and maybe some left over 4BT parts.

If I would ever consider using this 6BT, I would go with a GM adapter and accessories, so not having them up front is okay.
Besides, the 4BT will be giving up its GM Adapter and accessories as lived in a FritoLay Chip van.

So, how hard or expensive is it to rebuild a Cummins 6BT?
What mods can be performed on these first generation 12 valve engines?
Is this running core worth messing with?

_________________
Bryan Smith
2004 KIA Optima (wife 's DD)
1999 Jeep Grand Cherokee Limited (my DD)
1993 GMC 3500 extended length cargo van, 6.2L Diesel powered.
1982 J10 - current project, replacement AMC 360 sitting in the engine bay.
1981 J20 - stock with a super kewl commercial flat bed (stored, long term Diesel dually project)


Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Mon Aug 11, 2008 1:16 am 
Offline
Thread Necromancer
User avatar

Joined: Thu Sep 11, 2003 7:25 pm
Posts: 29263
Location: Omokok, NI
Not sure what it takes to rebuild one complete.
My guess is that it smokes from leaky injectors, and loss of power from a head gasket.
I'd throw a new headgasket on it, properly adjust the valves, and get some new injectors and see what it does.
Depending on if its a 91 or 91.5 it may or may not be intercooled.
The turbo will be a large 21cm^2 housing, change that out to a smaller housing, and you'll see better boost and quicker spool up. Or just change out the turbo completly for an HX35w.
Its possible the injector pump may also be the cause of your power loss, they don't like the new low sulfer fuels that are out, so its critical to run some sort of fuel treatment with lubricant in it.
As far as power, stock it should be rated at 145hp and 600ftlb of torque. With the right injectors, and easy to do pump mods should be able to easily see 300hp. and 800-1000ftlb.

_________________
Jeeper4Life wrote:
noone means any harm and that it's all in fun.. but then there's kennedy..

'46CJ2a/buggy project in the works, yeah, still have those parts.
'14 Chebby Silverado, 4x4
'88 GMC S15 Trail Gypsy
A sweet lawn mower
Motorcycles: '14 HD FLHTCU, '92 HD FXRS, '26 HD JD, '02 Suzuki DRZ400, '56 Cushman Eagle, '48 Simplex ServiCycle, '72 Honda MiniTrail50, '81 Yamaha YR250, Probably some other stuff
"Tell me and I'll forget. Show me and I'll remember. Involve me and I'll understand." - Confucius
Image.................................................... ImageImage
"Concern yourself with what is right and you'll never second-guess that decision"
I'm not really an asshole, I just play one on the internet!


Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Mon Aug 11, 2008 10:31 pm 
Offline
Killed his Hooptie Geo Prism
User avatar

Joined: Mon May 08, 2006 8:49 pm
Posts: 202
Location: Fort Wayne, IN
Thanx!
Sounds like this maybe something I should grab.
From what I've read, you are very correct...turbo, IP and injectors would cause these issues.
So, while the 6BT maybe free, it looks as if I would spend $$$ on replacing these parts to make this a healthy runner again.

_________________
Bryan Smith
2004 KIA Optima (wife 's DD)
1999 Jeep Grand Cherokee Limited (my DD)
1993 GMC 3500 extended length cargo van, 6.2L Diesel powered.
1982 J10 - current project, replacement AMC 360 sitting in the engine bay.
1981 J20 - stock with a super kewl commercial flat bed (stored, long term Diesel dually project)


Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Mon Aug 11, 2008 11:30 pm 
Offline
Thread Necromancer
User avatar

Joined: Thu Sep 11, 2003 7:25 pm
Posts: 29263
Location: Omokok, NI
One of the better firstgen boards is www.dieseltruckresource.com also try www.cumminsforum.com

_________________
Jeeper4Life wrote:
noone means any harm and that it's all in fun.. but then there's kennedy..

'46CJ2a/buggy project in the works, yeah, still have those parts.
'14 Chebby Silverado, 4x4
'88 GMC S15 Trail Gypsy
A sweet lawn mower
Motorcycles: '14 HD FLHTCU, '92 HD FXRS, '26 HD JD, '02 Suzuki DRZ400, '56 Cushman Eagle, '48 Simplex ServiCycle, '72 Honda MiniTrail50, '81 Yamaha YR250, Probably some other stuff
"Tell me and I'll forget. Show me and I'll remember. Involve me and I'll understand." - Confucius
Image.................................................... ImageImage
"Concern yourself with what is right and you'll never second-guess that decision"
I'm not really an asshole, I just play one on the internet!


Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Tue Aug 12, 2008 5:38 am 
Offline
Likes redheads from Disneyworld
User avatar

Joined: Tue May 27, 2008 8:34 am
Posts: 468
Location: Huntington, IN
What do you want to put it in if you rebuild it? The 3500 or another truck? I think I missed something... :?


Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Tue Aug 12, 2008 6:29 am 
Offline
Killed his Hooptie Geo Prism
User avatar

Joined: Mon May 08, 2006 8:49 pm
Posts: 202
Location: Fort Wayne, IN
tommy_chunk wrote:
What do you want to put it in if you rebuild it? The 3500 or another truck? I think I missed something... :?

I dunno yet.
I had planned to swap a 6.2L Diesel into my Wagoneer, but things have changed and I sold my Wagoneer.
I have my J20 and my J10 J Series trucks I could swap this 6BT into.

I am not in a position today to do anything with it.
But, because this 6BT Free, I might grab it and sit on it for a future project.
The owner still has it and we just talking now...so maybe this deal will fall through...I dunno.
I was just asking some questions to see if this running core was worth bringing home.
Sounds like maybe it is.
So, my plans are, if the deal works out, to go get it, prepare it for long term storage, maybe collect some additional parts
and just wait for the day when I able to use it.

_________________
Bryan Smith
2004 KIA Optima (wife 's DD)
1999 Jeep Grand Cherokee Limited (my DD)
1993 GMC 3500 extended length cargo van, 6.2L Diesel powered.
1982 J10 - current project, replacement AMC 360 sitting in the engine bay.
1981 J20 - stock with a super kewl commercial flat bed (stored, long term Diesel dually project)


Last edited by The PIG Smith on Tue Aug 12, 2008 5:35 pm, edited 1 time in total.

Top 
 Profile  
 
 Post subject: Re: Cummins 6BT Questions
 Post Posted: Tue Aug 12, 2008 11:42 am 
Offline
Thread Necromancer
User avatar

Joined: Thu Sep 11, 2003 7:25 pm
Posts: 29263
Location: Omokok, NI
If anything, you could probably make a quick buck off of it too. I'd think that a running complete core would be worth atleast $500...

_________________
Jeeper4Life wrote:
noone means any harm and that it's all in fun.. but then there's kennedy..

'46CJ2a/buggy project in the works, yeah, still have those parts.
'14 Chebby Silverado, 4x4
'88 GMC S15 Trail Gypsy
A sweet lawn mower
Motorcycles: '14 HD FLHTCU, '92 HD FXRS, '26 HD JD, '02 Suzuki DRZ400, '56 Cushman Eagle, '48 Simplex ServiCycle, '72 Honda MiniTrail50, '81 Yamaha YR250, Probably some other stuff
"Tell me and I'll forget. Show me and I'll remember. Involve me and I'll understand." - Confucius
Image.................................................... ImageImage
"Concern yourself with what is right and you'll never second-guess that decision"
I'm not really an asshole, I just play one on the internet!


Top 
 Profile  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 7 posts ] 

Board index » 4x4 Related Technical Forums » Misc 4x4 Tech


Who is online

Users browsing this forum: No registered users and 7 guests

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

cron