B670 Backhoe for B7100

JRHill

Active member

Equipment
Orange: B7100 Std and Woodmizer; Green/yellow JD Buck, Gator and 410j.
Apr 26, 2016
228
185
43
Wahkiacus, Washington
One of these days my 8hp Tecumseh log splitter is gonna have that engine put to sleep with a .308. I relish the day. So before I have that party I am researching the pump on the backhoe as in some quick disconnects to run off the PTO backhoe pump to power the splitter. I would have the pressure and return right off that pump with quick disconnects, using the hyd tank on the splitter.

But before I go any further I need to know the pressure and GPM for the pump on the Kubota B670. It's physically the same size as the pump on the splitter but the splitter has a two stage pump. I don't think I should just swap them. I think the splitter's pump could generate too much pressure for the hoe. OTOH, I don't know if the B670 pump has the umph, so to speak. The splitter's pump can not be spec'd - all I know is they 'look' identical. Of course the splitter's pump runs straight off the engine at governed speed, say 3600 rpm, if and when it actually runs. The PTO pump for the backhoe is of course much slower RPM but I could run it in the 3rd range.

Has anyone done anything like this?
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
One of these days my 8hp Tecumseh log splitter is gonna have that engine put to sleep with a .308. I relish the day. So before I have that party I am researching the pump on the backhoe as in some quick disconnects to run off the PTO backhoe pump to power the splitter. I would have the pressure and return right off that pump with quick disconnects, using the hyd tank on the splitter.

But before I go any further I need to know the pressure and GPM for the pump on the Kubota B670. It's physically the same size as the pump on the splitter but the splitter has a two stage pump. I don't think I should just swap them. I think the splitter's pump could generate too much pressure for the hoe. OTOH, I don't know if the B670 pump has the umph, so to speak. The splitter's pump can not be spec'd - all I know is they 'look' identical. Of course the splitter's pump runs straight off the engine at governed speed, say 3600 rpm, if and when it actually runs. The PTO pump for the backhoe is of course much slower RPM but I could run it in the 3rd range.

Has anyone done anything like this?
#1 You can not do that, it's an open system.
#2 It's going to be slower than snot!
 

TheOldHokie

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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
windyridgefarm.us
One of these days my 8hp Tecumseh log splitter is gonna have that engine put to sleep with a .308. I relish the day. So before I have that party I am researching the pump on the backhoe as in some quick disconnects to run off the PTO backhoe pump to power the splitter. I would have the pressure and return right off that pump with quick disconnects, using the hyd tank on the splitter.

But before I go any further I need to know the pressure and GPM for the pump on the Kubota B670. It's physically the same size as the pump on the splitter but the splitter has a two stage pump. I don't think I should just swap them. I think the splitter's pump could generate too much pressure for the hoe. OTOH, I don't know if the B670 pump has the umph, so to speak. The splitter's pump can not be spec'd - all I know is they 'look' identical. Of course the splitter's pump runs straight off the engine at governed speed, say 3600 rpm, if and when it actually runs. The PTO pump for the backhoe is of course much slower RPM but I could run it in the 3rd range.

Has anyone done anything like this?
l

  1. Your hoe and splitter are protected by inlet reliefs in the control valves so no such thing as "too much pressure".
  2. Tbe two stage pump makes higher flow at lower (~800) PSI and flow drops way back to develop full pressure. Not what you want for a hoe.
  3. The PTO pump runs slower but has a much larger displscement to make up for that. It produces full flow and pressure at all times.
  4. Speed of the splitter is going to depend on cylinder stroke and bore and displacement of the PTO pump. See if you can find a number on it.
Dan
 
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TheOldHokie

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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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113
Myersville, MD
windyridgefarm.us
  1. Remove return line from backhoe reservoir and stick it in an empty 5 gallon bucket..
  2. Disengage PTO, start tractor, and set enginel speed to 540 PTO speed
  3. Engege PTO and time how long it takes to fill bucket to 4 gallon marrk

You now kmow flow rate @540 pump RPM.

Dan
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
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Greensville,Ontario,Canada
$249 gets you a replacement engine for the splitter from HF. With just a little TLC ( drain carb, run engine dry ) ,it'lll probably outlive you.