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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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Discussion Starter · #1 ·
Stock pump 4939585, high volume is 4939587. Anyone have issues running one or the other? Or is it a bolt in and run affair.

The pump coming out (4bt) is 3932449, parts.cummins.com says 4939587 for the replacement which appears for the 6bt.
Thanks,
Sam
 

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I am running the 6BT oil pump in my 4BT bolted in no issues, with oiling 2 turbos and the larger flow piston cooling nozzles it brought my oil pressure back to high normal from almost too low this was on a new build.
 
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Cummins changed which oil pump they used over the years. The 4b has a pump which flows 12.2 GPM and the 4bt is 14.4 GPM. A 6bt was around 16 GPM and that pump appeared on the later 4bt engines, especially the 16 valve models. There are some pumps that now exceed 20 GPM. In general, the stock spec pump is fine unless you are running twin turbos like Steve. You also consider changing to a 7 plate oil cooler like the 6bt on those engines. One positive aspect of the higher flowing pumps is the oil gets cleaned in the filter more often. One thing you will find on some pump specs is they are rated at 4200 RPM which I believe is twice crank speed.
 

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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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39 Posts
Discussion Starter · #4 ·
Appreciate the information. Sounds like there are no red flags except that the oil could run a little hotter with only a 5 fin oil cooler. Looks like from the drawings the gear shaft slab might sit out farther from the block and business end, maybe to get the gears right up on their shaft bearing surface.

Accessory oil requirements would be hx30w and dodge vac/ps pump so it could be overkill but I don't see any major no's.
Thanks,
Sam

P.S. Steve, I read through your build thread a few weeks ago but missed pictures linked to the host website. If you had a link to your thread pictures, I'd be interested.
 

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I lost everything from the build except for the last couple of years work, but if you would like pics of something in particular I'd be happy to get some for you.
 
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It's normal to run the 6BT pump and cooler in a 4BT.

A high volume pump for a B series would be the C series oil pump. Many 6.7's are plagued with low oil PSI. The fix is the 8.3 pump.
 

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There was one thing brought out years ago that said you shouldn't run the 7 plate cooler on a 4bt because it over cools the oil. Never thought oil could get too cold in an engine unless you were in sub zero climate. Running the 7 plate with twin turbos would probably be fine since you are cooling oil from a second turbo.
 

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Char, agree on the overcooling, cannot be colder than the coolant. My 6BT runs around 15-20 above coolant temperature while cruising
 
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