Log splitter pump too large for engine

[rdorr]

Hello, I am building a log splitter. My question is " what happens to performance if you use a pump that requires more HP than the engine can deliver? " Ideally, from reading these forums, I think my setup should have a 22 GPM pump. However I can buy a new Haldex 28gpm pump much cheaper than I can buy a 22 GPM Haldex from Northern (taking tax & freight into the equation). The components that I already have are 14HP B&S vee, 24" ram,( 4" diameter with a 2.6 inch dia rod), Cross 30GPM valve, Easy Flow return line filter 50 gpm with 25 psi bypass. Any help/ comments much appreciated

 

[loadthestove]

Alot of variables come in play with your question,But basically if pump is to big for engine it simply will not pull it and motor will stall anytime load is applied .or motor will run under a severe strain to the point of failure

this video is a prime example of a load to big for a small engine..Small car, big camper - YouTube

Im sure others will give you a better explanation.

 

[wndwlkr]

The 14 HP will run the 28 gpm pump just fine .

 

[Mac88]

Hello, I am building a log splitter.
The components that I already have are 14HP B&S vee, 24" ram,( 4" diameter with a 2.6 inch dia rod), Cross 30GPM valve, Easy Flow filter 50 gpm with 25 psi bypass. Any help/ comments much appreciated

If your engine is vertical shaft, make sure the pump you buy will work in the vertical position. Some won't. Northern has a Q&A regarding vertical mounting. They can tell you what will work and what won't. You will have to fabricate your own mount. If it's a horizontal shaft engine then no problem.

 

[Kevin in Ohio]

The formula for needed engine size is:

HP Required = Flow Rate (GPM) x System Pressure (PSI) / 1714 x %Pump Efficiency

I believe the Haldex 28 GPM pump is 85% efficient. A 12HP is the bare minimum but I'd recommend to err on the big side.

A lot of motors HP ratings are, shall we say, questionable. Couple that with wear and tear bringing it down powerwise I'd go a little bigger from the start.

With a 28 GPM pump you'll need a large tank for fluid as well. Rule of thumb is to equal pump output. In this case 28 gallon. Keep as many 90 degree bends out of the system as possible too. Heat becomes a BIG factor when throwing that much fluid around. As you mentioned, you have to watch your valves, strainers and filter to make sure they can handle the flow rate as well.

 

[kevin j]

Not much differeence. That is a two stage pump.

check the haldex site, but I think the 22 and 28 both have the same small gear set, thus the same small flow, so you can pull the same final pressure for the given engine same hp.
14 hp should pull 2500 psi or more on either pump, with the same small gear set.


The larger gear are different, thus 28 vs 22 when you add small plus large gear sets.
You may have to set the unloading pressure (when it unloads the large gear set and 'shifts' from 28 gpm to probably 7 to 8 gpm) a bit lower. Since pressure x flow is hp, more flow means less pressure for the same hp. Won't matter much. Instead of pulling 22 gpm to say 900 psi, it might pull 28 gpm to 700 psi. So you just set the unloading pressure until the engine maxes just before it unloads to the slow speed.