16 GPM Pump with 1.8 GPM On High Pressure Side

[FLRA_Dave]

I have been looking to swap my 11 gpm pump out for a 13 gpm (looks like they generally share the same size high pressure section???). I was looking on Surplus Center and noticed that they had a 16 GPM pump that has a smaller high pressure section (1.8 gpm vs the 11 & 13 at 3.4 gpm). Most of the wood I cut is no more than 12" or so in diameter (Ash and Poplar lately).

This is the pump:

It is preset to switch over at 500 psi... which might be too close to what I'm guestimating I would develop with my 5 hp B&S.

My original thought was to go with this pump and upgrade the engine when I come across one. I tried searching, but didn't see any posts on anyone on here using this pump. Seem like an OK idea? Or is this likely going to produce some bad results?

This is what I came up with for values:

I need to get a gauge on my splitter as well... I'm winging it with the pressure limits.

 

[dave_dj1]

That may be too much pump for a small motor.
I don't understand why you would want a slower high pressure mode?
You can always upgrade the motor sooner than later if the 5 hp isn't enough.

 

[motoman3b]

Where are you getting 1.8gpm? The specs on the pump you posted say 3gpm, there's a direct correlation between the high and low side, ie. 16gpm low pressure setting will still require a 8hp motor so why settle for one where the high pressure side is even slower!

 

[FLRA_Dave]

Where are you getting 1.8gpm? The specs on the pump you posted say 3gpm, there's a direct correlation between the high and low side, ie. 16gpm low pressure setting will still require a 8hp motor so why settle for one where the high pressure side is even slower!

What the beans... I was looking at it over the weekend and I'm positive it was showing 1.8... Didn't pay attention to it this morning when I posted. Still is lower than the 3.4 for the other pumps.

 

[FLRA_Dave]

If my chart is close to what I may be looking at for PSI on the high flow section of the pump (536 psi), then I guess it wouldn't matter if you are running 5 hp or 8 hp before switching to the low flow section (500 psi) - and the low flow section would provide plenty of psi (at least more than what it currently does IF my high pressure side is 3.4 gpm). I notice that those MTE pumps that I was looking at are rated for 3800 rpms... so maybe they flow less at 3600???

From looking at the spec sheet... looks like 500 psi is the only pressure for unloading? Not adjustable? So if I went to a larger engine, then it wouldn't change how it operated over the 5 hp (other than increasing the highest tonnage).

I was fine with the slower speed on the high pressure section... seems like that's only 10% or less of the time anyhow. Although with a lower unloading pressure that would make it trip more often... hmmm.

Oh yeah... I found out where the 1.8 gpm came from - it was the 11 gpm version of the same style pump.

 

[FLRA_Dave]

This is my splitter... a slightly modified Deere Model 52. I don't have much info on the specs for it other than what's in the chart I was showing (and the pump info was a guess).

I have no idea why they put such a small reservoir on them... 1 gallon - maybe??? I was thinking about getting a 5 gallon for it. I know I keep reading 1 gallon / gpm, but if it made it this far, then I'm sure it would be happy moving up to 5 gallons. I think anything larger is going to "overpower" the splitter.

 

[FLRA_Dave]

I guess the best way to approach it would be to capture some data and see how it trends.

1st I need to get a pressure gauge

2nd I need to keep track of MAX psi on low / high pressure stages individually

3rd I need to keep track of percentage of occurrences that high pressure stage is reached.

4th Review the data and see where most of my splitting is occurring

Now how to track this data automatically is going to be the tricky part:msp_confused:

 

[dave_dj1]

I'm not sure how to explain this but I will try. It's not just about gpm's, you are moving more volume, volume takes power. Try pressing a shot glass down in to a cup of water, now try pushing a water glass into the same cup of water. It will take more power to push the water glass in and displace more volume.

 

[jh35]

I have a 16gpm 2 stage on my home built splitter with an 8hp briggs and stratton. 8hp is what tghe manufacturer of the pump called for. No my Briggs doesn't work hard and maybe you could get away with less, but.......

 

[nathon918]

maybe its just me but, i cant wrap my head around replacing an 11 gpm pump for a 13 gpm pump.
for the possible 1-2 second better cycle time?
also replacing more then likely a quality US made 11 gpm pump with a 13 gpm chinese POS, if your going to do it atleast put a Barnes pump on it!
and as for putting a 16 gpm pump on it, even if your motor will turn it, will the rest of your system support that flow?? probably not!
increased flow in a system not designed to flow that much will cause heat! and that 1 gal resevior you have will most likely cause the pump to cavitate (starve the pump of oil).
just letting you know theres more to a hydraulic system than you think...

 

[Oliver1655]

I have a Haldex 16gpm 2 stage pump on my splitter. Rule of thumb for the Haldex series of 2 stage pumps is the low side is 1/4 of the high side. (11 high 2.75 low, 13 high 3.25 low, 16 High 4 low, 22 high 5.5 low, 28 high 7 low). They are factory set to shift at 600 psi. Unless I am splitting elm, hedge or really knotty rounds, 90% of my splitting is done in the high stage. I use a 4"x24" cylinder with a 1.75" rod. I can see where it would have the potential to speed up the cycle times changing to a larger pump. ps - the pressure relief on my vales are set at 2,500 psi. With a sharp wedge I have no problem splitting whatever I want. Approximately 15.9 ton

 

[whitepine2]

I have a 16gpm 2 stage on my home built splitter with an 8hp briggs and stratton. 8hp is what tghe manufacturer of the pump called for. No my Briggs doesn't work hard and maybe you could get away with less, but.......

This is what I have 8 B&S and 16 GPM,works fine can stall B&S but one learns how much to force,B&S came from dump was on gen. so not new but has done it's job for 3 Yrs and still going. Just got done replacing 1/2" with 3/4
lines I want to get 22 or 28 GPM pump and bigger engine. I find with 3/4" oil stays cooler(a good thing) and about 2 seconds faster,however I have a 5" piston and 30" stroke so I need more oil for faster speed.
What I have now works and for a few cords a year is ample,but I do about 15 to 20 and need the speed or at least I think I do.
Good luck whitepine2

 

[FLRA_Dave]

I've split about 14 cord since this past October on my little splitter. I noticed today that it seemed like it was a little slower than normal... So I opened the cap to the tank and the hydraulic fluid was tan colored. I had clean fluid in it this past fall. My guess is that is due to the small tank size? I think the tank will be the first to be upgraded.

 

[nathon918]

I've split about 14 cord since this past October on my little splitter. I noticed today that it seemed like it was a little slower than normal... So I opened the cap to the tank and the hydraulic fluid was tan colored. I had clean fluid in it this past fall. My guess is that is due to the small tank size? I think the tank will be the first to be upgraded.

tan or milky oil, almost always means theres water in the system...

 

[FLRA_Dave]

tan or milky oil, almost always means theres water in the system...

How do you suppose water got in the system? Condensation?

 

[nathon918]

How do you suppose water got in the system? Condensation?

usually throught the breather.
what type of breather is on it?

 

[FLRA_Dave]

usually throught the breather.
what type of breather is on it?

I'm guessing the pin hole in the fill cap is the breather. Reminds me of the old metal gas cans that had holes in them.

From JD Parts:

 

[FLRA_Dave]

Will someone please review my XLSX for me? I figure I have to be missing something...

https://www.dropbox.com/s/4wrtvswn72r28t2/SPLITTER_GPM_VS_HP_VS_FORCE.xlsx

Also... the blue cells are editable.

 

[Patrick62]

I can't do exls

I can barely do computer if it has a logo of a fruit with a bite outta it.

Hydraulic Cylinder  Speed Calculator

Wanting to go to the 16gpm pump is a excellent idea. Ditching the tank is also a excellent idea. You will not have enough oomph with a 5hp to pull the larger pump. going with a 13.5 isn't enough change to justify the expense (your motor would pull it, barely). So what are ya gonna do?

Upgrade to anything that will do 8hp, and get the larger pump. You will have a splitter that will be fast enough to "get er done", with enough muscle to break bowling balls. I tried to pull a 16gpm with a 6.5, and it isn't quite enough. You can adjust the transition pressure on the pump to compensate for a weak engine. You also have to watch the kickout pressure on the valve. If you are running a smaller than ideal tank it will warm the oil faster. Just quit for a hour or two, let it cool. You can get 16 gpm thru 1/2 inch hoses, but it is marginal and generates more heat in the oil than you really like there. Put a larger tank on it.

As a bonus point you will discover that a modern OHV engine will use less fuel than the old flat head and make lots more power.

 

[FLRA_Dave]

From the looking at the diagram…

1 - The ½” OD lines need (#7 & #8) to be replaced with ¾” lines.
2 - The 90 degree fittings (#6) needs to be replaced with ¾ NPT x ¾ NPT (or removed and 3/4" NPT lines threaded directly onto cylinder & valve???)
3 - Upgrade to larger hydraulic reservoir.
4 - By the looks of the size of the elbow coming off the pump (#14 - ½” NPT) the above upgrades wouldn’t be too fruitful (I’m sure the ½” OD lines feeding the cylinders is no good - 3/8” ID???).
5 - “T” in my pressure gauge right before the valve.
6 - Buy a new pump (16 gpm). (EDIT: just realized that 3/4" lines don't come into play until 22 GPM???)
7 - Get a new motor (the 8hp from my snow blower that I hardly ever use - put 5hp on it?) to run a larger pump.

I think that's my game plan...