# Horsepower and GPM Hydraulic Pump Question



## NC Firewood (Aug 26, 2010)

I've kept one splitter since purchasing my processor and believe it has an 11 or 16 GPM Haldex on it now. The engine is a wisconsin THD, and from what I have found online it makes about 16.8 HP. The cylinder is either a 4" or 5". I am looking for more speed and am looking into the 28 GPM Haldex Barnes. Before I spend the $400, I'd like to make sure the engine has enough guts to turn the pump. Any help would greatly be appreciated.


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## TJ-Bill (Aug 26, 2010)

are you talking dual stage or single?

16GPM dual sound under rated for a 17 hp engine,, 28GPM Dual sounds about right.


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## NC Firewood (Aug 26, 2010)

It is the 2 stage pump 28 GPM I'm looking for, I have been able to bog the motor down on extremely large pieces, didn't know if that was lack of HP, small hydraulic pump, cylinder too big, or all three.


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## triptester (Aug 26, 2010)

A healthy 16hp. will handle a 28 gpm 2-stage pump. But if the original 11 or 16 gpm 2-stage pump is bogging the 16 hp. engine either the engine is weak or the pump is set wrong.


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## Haywire Haywood (Aug 27, 2010)

I'm running my 28 on an old 18hp Briggs scavenged off a junk lawn mower. It does fine.

Ian


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## NC Firewood (Aug 27, 2010)

Sounds like im going to order it, the motor runs fine, I think the 48" cuts were too much for the little pump. I can always send it back and say it was the wrong inlet/outlet size or some other issue. We shall see, will let you know how it goes. Thanks


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## triptester (Aug 27, 2010)

The size of the pump has nothing to do with the max. pressure or tonnage . 
If you just change out a 11 gpm 2-stage pump with a 28 gpm 2-stage pump the only thing that will change is the cycle time. Tonnage will be the same.

Max. tonnage is determined by the bore size and rated pump pressure. Most 2-stage pumps are rated at 3000 psi.

Cycle times are determined by gpm and bore size.

If your engine is bogging now with a small pump it may bog worse with a bigger pump.


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## pipehead (Aug 27, 2010)

A rule of thumb is 1/2 HP for every GPM. This is only a rough reference, so take it for what it's worth.


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## nparch726 (Aug 27, 2010)

Don't know if they're any good or not, but the price makes the IFP pumps somewhat attractive. $229 for the 28 GPM pump.

http://www.cylinderservices.net/catalog.asp?prodid=519511


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## TJ-Bill (Aug 27, 2010)

pipehead said:


> A rule of thumb is 1/2 HP for every GPM. This is only a rough reference, so take it for what it's worth.



I thought that was a rough rule for dual stage pumps? 

does it matter? I'm just about to try my rebuild with 11HP honda and a 12 GPM single stage.. I was going to get a 16 GPM dual but I figured use what you got and upgrade when she breaks. I would think 22GPM for a 11 HP would be abit much.


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## jerryw66 (Aug 28, 2010)

My splitter has the THD engine and the 28 gpm pump, 4"X24" cyl. I usually run the engine at about 1/2 throttle, or about 2000 rpm, it does great, cycle times from about 7 to 10 seconds are nice, max pressure at 2500, and it splits everything I throw at it. At wide open throttle, the engine is governed to 3600 max rpm, and it seems a little quick, and noisy for me. Just a little slower is more my pace.


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## NC Firewood (Aug 28, 2010)

Greatly appreciated, this site has always been a blessing, should have the pump in a week or so.


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