Cummins 4 BT source....

[The Rage]

Originally posted by mcinfantry
2500 for a 4bt

500 for a 12valve? buy it!

Actually 2500 seems a bit high for a mill with lotza miles on it you know?. The "other" project (can I mention it here?) is a 1980 Chevy C-10 former crap diesel factory converted to a 350 Olds V8...Good ole' motor. BUT horrific mpg running in front of a Turbo 350 and a 4:11 gear (10mpg at BEST!)....I could probably get away with the T-350 BUT if the Frito Lay Vans are running Chevy T-400's, I'd have to swap it anyway to make it fit..(Just makes more sense that way)..Definately a T-400 if I ran the Cummings 6..Too much torque I believe for a Turbo 350 maybe If I wanted OD, I'd rather convert to manual tranny/clutch than pay the extra to have a decent R-700 built to manage the torque.

The PW I'm looking at, I stand corrected..It's a '79...The only thing I worry about is the fuel tank lift pump that gave all the MOPAR owners fits in the earlier cummings-equipped trucks. What's the work-around for that reliability issue?..Third-party pump?

Thanks for the reply...BTW, if I'm going to spend 2500 bux for a mill alone, I'd rather go ahead and buy the entire bread/cornchip truck for 2900 you know?. There's been times I could've used something like that for hauling stuff.

Bryan

[MoparNorm]

Good Post Bryan!
MN

[warlock440]

Originally posted by The Rage

The PW I'm looking at, I stand corrected..It's a '79...The only thing I worry about is the fuel tank lift pump that gave all the MOPAR owners fits in the earlier cummings-equipped trucks. What's the work-around for that reliability issue?..Third-party pump?

Bryan

What problems did they have with the early lift pumps?? I have both a 93 and a 94 and have not had anyproblems with the lift pumps.. The only Dodges I have heard of having problems with lift pumps are the 98 and up so can you enlighten me on the early problems??

[The Rage]

Originally posted by MoparNorm
Good Post Bryan!
MN

Well, thank you. BTW, I have met a new friend on Ebay from Shelby, NC that used to work on the 4ATs and 4BTs fpr a bread company. He said an amazingly quick engine for a 4-bangin' diesel. I didn't think to ask what the rear end ratio might've been though as top speed on a bread truck, mostly used for urban and suburban deliveries, was probably running a Big Mama ratio. What would you think?. 4:89 or so maybe? Probably worked as a governor for top speed too. I do know the trolley replicas that roll around Columbia can't do over 48 mph because they're running a 5 something rear end or so I was told.

Without having seen one of the manual trannies out of a bread box, how BIG are they and did they go granny low to 4 straight (Like a Ford), 4 speed OD, or 5 speed od. Also, how about a 2-speed rear end OR are we getting out of hand there with a C-10 <grin>?

Obviously, I want the Dodge to be my mud truck. I probably wouldn't mind going with a big rear end as possible if the price wasn't too outrageous seeing as street use would be very limited. The Chevy would be the daily trash truck/usual driver UNLESS someone wants to sell/give me a decent Dodge Stepside as a possible transplantee?

[The Rage]

Originally posted by warlock440
What problems did they have with the early lift pumps?? I have both a 93 and a 94 and have not had anyproblems with the lift pumps.. The only Dodges I have heard of having problems with lift pumps are the 98 and up so can you enlighten me on the early problems??

Acquaintance of mine had trouble with his '94 and I've heard about some of the real early, old design (90, 91) having probs too. BUT if you say they're more reliable than the 98's, then I say hooray!.

BTW, answer me this dumb question. Was a lift pump always a necessity with the 6bt and why not with the 4bt?.

If I can find a 6 to go in either project, I'm happy BUT if the 4 will suffice at the rite price, well, then I'll go the reliable, albeit slightly slower route with the 4bt.

Is there a 3rd party pump that solved the problems/improved performance though for the 6bt? Thanks

[rlmeskimen]

Afternoon, I just ran into this thread doing some research on 4bt's and thought I would drop my two cents on the lift pump issue.

1988-1993 12V Cummins used the VE6 Rotary injection pump. I don't know a lot about this pump except that it was difficult to tweak and make a ton of power but don't think it was unreliable.

1994-1998 12V Cummins used the P7100 Inline injection pump. It was purely a mechanical injection pump and did not use or require a second pump to "lift" the fuel from the tank to the injection pump. The P7100 is a rather bullet proof pump and I have heard of very few issues with this pump.

1998-2002 24V Cummins utilized the VP44 injection pump. This pump used an ECM to control the pump and injectors. These models used a Carter "lift" pump to get fuel at 5-7 PSI from the tank to the injection pump. This pump was designed to be a pusher pump but was instead attached to the engine thus there were issues as it was in a suction type setup. Issues seam to be more common on the long bed quad cab truck (not sure there was any statistical significance) so some speculate that the extra bit of cab was enough to tax the pump. This in and of itself was not the issue as Dodge warrantied the pump to 100K and it was around $100 to replace after warranty. The larger issue was the VP44 could compensate for the weak lift pump once it died but only for so long and then it would die. If you were beyond the warranty you were on the hook for the lift pump and the additional VP44 which ran you a cool $1300!

There were numerous ways to fix this and many folks do after the warranty is up. Usually, the pump it moved to the rear by the tank or you use an aftermarket setup (FASS is one) and rendered it a moot issue. In the meantime, the hot ticket was to mount a fuel pressure monitor gauge in between the lift pump and the injection pump to monitor pressure. It was obvious when the lift pump would go with a gauge. There are a couple of easy points to monitor from.

That's about all I know about that issue. For anything and everything you want to know about these engines and trucks goto www.turbodieselregister.com . Hope this helps some.

Ryan Meskimen

[JimmieD]

The Walbro 3951 or 3952 [double check those numbers, guys, it's from memory] is a fuel-cooled gear-rotor pump and quite bulletproof. Using it in a little old 6BT is like using a fire truck pump to take a shower with, meaning it's WAY OVER pumping power for the job. That's good, 'cause it means they last for years and years with zero problems. If you use the smaller one, I think it's 3951, for a 4 BT it's prefect and major overkill for ANY of your fuel needs. Don't try to use the Holley 'Blue' pump because it's made for gasoline, and not the heavier diesel fuel. Can't take the load.

If at all possible use the early engines without the IC electrical garbage and ECM, as it's nothing but headaches. You can still bomb the early engines, 4BT or 6BT and get all the power you'll ever need. Easy to get 250 hp and 500+ ft lbs torque from a 4BT!! 175-200 hp is a better number to shoot for reliability wise.

You can't go by the Frito Lays rear end ratios 'cause they have huge tires on them, 19-20 inch wheels, so it throws the numbers off when running 33's to 38's. Usually somewhere between 4.89 and 4.10 is a good ratio, depending on the tranny you use.

The TH400 was hard pressed to handle even the 4BT and that's one of the main problems that caused so many of these vans to be retired: not worth the money to continuously repair, or the money to swap in a better tranny.

FAR BETTER for you to score an NV-4500 DODGE tranny, bellhousing adapter and bellhousing with hydraulic clutch. NV-4500 has granny low, good ratios, and a 27% overdrive in 5th. You got your grunt, plus drivability, PLUS OVERDRIVE for good mileage! Not only that, but FULL SYNCHRO IN ALL GEARS INCLUDING REVERSE HA HAHA!

Second choice is the SM465 4 speed, but not for me.....

Extra attention to details of fuel filtration is mandatory, and also to an adequate [or Walbro overkill] lift pump with a 4BT. That's about all those 'little' engines want and otherwise they run and run and run. Use a 6BT bellhousing adapter, bellhousing, flywheel, clutch etc. as it bolts right on and you have far more clutch than the 4BT will ever need.

JimmieD

[Gordon Maney]

Well, thank you. BTW, I have met a new friend on Ebay from Shelby, NC that used to work on the 4ATs and 4BTs fpr a bread company. He said an amazingly quick engine for a 4-bangin' diesel. I didn't think to ask what the rear end ratio might've been though as top speed on a bread truck, mostly used for urban and suburban deliveries, was probably running a Big Mama ratio. What would you think?. 4:89 or so maybe? Probably worked as a governor for top speed too. I do know the trolley replicas that roll around Columbia can't do over 48 mph because they're running a 5 something rear end or so I was told.

Without having seen one of the manual trannies out of a bread box, how BIG are they and did they go granny low to 4 straight (Like a Ford), 4 speed OD, or 5 speed od. Also, how about a 2-speed rear end OR are we getting out of hand there with a C-10 <grin>?

Obviously, I want the Dodge to be my mud truck. I probably wouldn't mind going with a big rear end as possible if the price wasn't too outrageous seeing as street use would be very limited. The Chevy would be the daily trash truck/usual driver UNLESS someone wants to sell/give me a decent Dodge Stepside as a possible transplantee?

What is a 4AT?

[JimmieD]

The 'A' designation referes to 'Aftercooled'. Correctly 4B, naturally aspirated, 4BT, Turbocharged, and 4BTA Turbocharged and Aftercooled. Mostly the 4BTA are later engines, not necessarily desirable due to sometimes complex electronics. 4BT requires 1 [ONE!] wire and the 4BTA/IFC engines have a whole loom fool of foolishness. Many 4BTA are IFC with computer controls, but not all.

[rlmeskimen]

Jimmie, thanks for clearing up the lift pumps on the 12V...I am not super familiar with them only the issues with the 24V ones as the two Rams I had fell in that category.

Ryan

[Gordon Maney]

The 'A' designation referes to 'Aftercooled'. Correctly 4B, naturally aspirated, 4BT, Turbocharged, and 4BTA Turbocharged and Aftercooled. Mostly the 4BTA are later engines, not necessarily desirable due to sometimes complex electronics. 4BT requires 1 [ONE!] wire and the 4BTA/IFC engines have a whole loom fool of foolishness. Many 4BTA are IFC with computer controls, but not all.

What is IFC?

[JimmieD]

Hi Gordon!

Not exactly sure what that acronym represents, but it refers to Bosch electronic fuel injection as opposed to on-demand Bosch mechanical fuel injection. As with any other component the increased perfection of fuel delivery comes with the price of complexity attached. The older Bosch system, though not elegant, is a Clydesdale for getting the job done simply and efficiently, with very easy tweaks to increase power. The later stuff is not very user friendly.

JimmieD

[CGarbee]

What is a 4AT?

Not sure about a 4AT, but Cummins did produce a line of inline six cylinder engines based off an Onan design that they acquired along with Onan a few years back that was the 6AT3.4. Six cylinder, aftercooled, turbocharged, 3.4 liter. Had a higher rpm limit than the larger, newer, 4B/BT/BTA or 6B/BT/BTA engines but not as much low end torque. Was used in a lot of the smallest route vans as repowers for the Chevy 292 (or 296, whatever that inline six cylinder gas engine was...).

I know of a guy in GA with a M37 that has the Cummins 6AT in it backed by a SM465 (the GM transmission that was behind it in the bread truck), and it gets up and down the road alright with the 5.83 gears, but even he says that if it were to be done over, that he'd install a 4BT in order to get more low end... 6 AT3.4 runs 120hp@3600rpm...

Hope that this helps...

[Gordon Maney]

Not sure about a 4AT, but Cummins did produce a line of inline six cylinder engines based off an Onan design that they acquired along with Onan a few years back that was the 6AT3.4. Six cylinder, aftercooled, turbocharged, 3.4 liter. Had a higher rpm limit than the larger, newer, 4B/BT/BTA or 6B/BT/BTA engines but not as much low end torque. Was used in a lot of the smallest route vans as repowers for the Chevy 292 (or 296, whatever that inline six cylinder gas engine was...).

I know of a guy in GA with a M37 that has the Cummins 6AT in it backed by a SM465 (the GM transmission that was behind it in the bread truck), and it gets up and down the road alright with the 5.83 gears, but even he says that if it were to be done over, that he'd install a 4BT in order to get more low end... 6 AT3.4 runs 120hp@3600rpm...

Hope that this helps...

You are saying that the 4BT produces more torque than the 6AT?

[The Rage]

I'm still searching for a good 4BT source in South/North Carolina or Georgia. See bread trucks on auction but they're equipped with gas 350's. I would REALLY like to do as another poster did with my C10 He put a 4BT in a 1980 C10. I would change out the 4.10 rear end for atleast a 3.73 or if I could order one, a 3.55.


But then again, if someone knows of a good Fedex/Frito-Lay complete box truck already equipped for a reasonable price, let me know.

Bryan
Joanna, SC