2 stage pump question, again

[firmwood]

8hp Briggs on a 16gmp 2 stage.

She putts pretty good around 650psi on the high flow stage, but when tripped into high pressure, engine about near free wheels like there's zero load., even @ 2000 psi.

I think this pump is 2-3gpm on the high pressure bore. I'm not sure without digging #s. But anyways.

Why couldn't I just buy a bigger pump, say a 21 or 28gpm, while also finding one Thsts 3-4 gpm on the high pressure side, and adjust the 2 stage a fuzz lower, yeah it'll jump into the 2nd stage sooner, but my idea is to encourage a faster cylinder retract, and extension, when there's basically no load.

All this to keep the engine the same, as it's a gas sipper, but I feel like I'm just pumping it into the air watching the cylinder creep out, and back in, with no load.

Only other way is to make my own ram and end cap, so I can have a tighter ratio bore/ram size, so it'll suck back like a rocket.

4" with 3.75" ram, or 6" with 5.75" ram., etc.

If needed I can make my own adapter, but anyone have any idea if a 8hp newer Era Briggs/tecumseh will handle 2k# @ 3-4, maybe 5gpm?

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[timbrjackrussel]

8hp Briggs on a 16gmp 2 stage.

She putts pretty good around 650psi on the high flow stage, but when tripped into high pressure, engine about near free wheels like there's zero load., even @ 2000 psi.

I think this pump is 2-3gpm on the high pressure bore. I'm not sure without digging #s. But anyways.

Why couldn't I just buy a bigger pump, say a 21 or 28gpm, while also finding one Thsts 3-4 gpm on the high pressure side, and adjust the 2 stage a fuzz lower, yeah it'll jump into the 2nd stage sooner, but my idea is to encourage a faster cylinder retract, and extension, when there's basically no load.

All this to keep the engine the same, as it's a gas sipper, but I feel like I'm just pumping it into the air watching the cylinder creep out, and back in, with no load.

Only other way is to make my own ram and end cap, so I can have a tighter ratio bore/ram size, so it'll suck back like a rocket.

4" with 3.75" ram, or 6" with 5.75" ram., etc.

If needed I can make my own adapter, but anyone have any idea if a 8hp newer Era Briggs/tecumseh will handle 2k# @ 3-4, maybe 5gpm?

Sent from my s-off'ed m7 with cm11!

For every gallon per minute at 1500PSI figure one horse power. A 8HP motor should do 4GPM at 3000PSI

 

[firmwood]

That's my next question. All they post and brag about is the low pressure flow.

I never see details of the displacement or flow per revolution for the high pressure side.

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[ChoppyChoppy]

That's my next question. All they post and brag about is the low pressure flow.

I never see details of the displacement or flow per revolution for the high pressure side.

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Pump flow normally is at max pressure in the spec sheets. That's why a hp chart will often show needing more power than real world since it's specing at 3000psi or whatever... well unless the application would be running at rated pressure constantly.

 

[firmwood]

I'll assume they over rate needed HP on high pressure side?

650psi @ 16gom about gags this 8hp.
3000psi @ 2pgm free wheels.



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[Del_]

I'll assume they over rate needed HP on high pressure side?

650psi @ 16gom about gags this 8hp.
3000psi @ 2pgm free wheels.



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The Barnes 16 gpm 2 stage is 3.5 gpm in high pressure mode.

http://www.northerntool.com/shop/tools/product_200321055_200321055

To speed things up adjust up the switch over pressure setting until the engine gets pretty loaded before switching over to high pressure/low volume.

 

[firmwood]

It's slow on the ram retracting, when irks already in low pressure /high volume.

So I was toying the idea to move to a bigger pump, that still doesn't overcome the engine when in high pressure/low volume, or just make a new ram that doesn't need as much oil to return.



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[farmer steve]

here's who i went with when i needed a new pump for my troy bilt. http://www.daltonhydraulic.com/hydraulic-pumps/log-splitter-pumps/2-stage-log-splitter-pump-2292
order on sat and had by wed. happy so far.

 

[muddstopper]

Dont know if you can find a 2stage pump the way you want it, but you can make your own two stage system by using two pumps in a hi/lo setup. Your 8hp engine will pull 6gpm at 2000psi and will pull 18gpm at650psi. If you buy a two section pump ,one section pumping 6gpm and the other section pumping 12gpm, you can set the pumps up using a unloading valve to achieve a low pressure flow of 18gpm and high pressure flow of only 6 gpm. Your motor will be maxed out in both setting, but you would be getting the maximum speed out of your splitter with your engine size. You would set the unloading valve at 650 psi to dump the high flow low pressure side back to tank while setting the relief to maintain the 2000psi of the low flow high pressure pump. As soon as the log split and pressure requirement dropped below 650psi, both pumps would then put 18gpm again to the control valve. This is assuming your engine has a real 8hp.

 

[firmwood]

I found some round stock and made a bigger ram. Cut threads to use the old piston

Found some flat plate stock and made a new end cap with bigger center hole. Lathed a groove for an oring. No pressure on return, so I didn't make it fancy.

4" bore, 3.5" ram. Find one of those in bailey's....

Works nice. 36" stroke on a 16 gpm, returns in under 2 seconds.

Hehehe. With a 4 way, it keeps 3 people from having time for a beer swig.
1 runs spools, 1 tails, 1 keeps rounds rolled up to the lift.



Now I uncovered another headache.... Elevator!

/me eyeballs the hydraulic motor under the bench

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