screaming splitter pump

[logjammed]

need a little hydraulic tutoring I am reviving an older built splitter (previous post monster splitter ) and have run the unit successfully through tractor hydraulics. currently powered by 17 hp three cyl. mitsubishi diesel. i got everything running and the pump noise makes me want to run away i thought the diesel would be the noise maker !! The pump is ccw rotation old ramp truck pto and runs of front of crank . pump is a 17 gpm single stage. the fluid seems aerated and i think it may be starving on the suction side as i had to reduce inlet to 3/4 from 1 1/4. before i attempt to re-size feed to pump from tank does anyone believe that this is my problem??? or should i attempt a 2 stage pump ccw rotation seems to be limited

 

[triptester]

The suction is positively to small. A 3/4" suction will only handle a pump half that size.

 

[North of 60]

Does it have a filter on the suction side? What condition is it in?
N of 60 :coolhmm:

 

[BrotherBart]

Take that suction line up to at least one inch for that 17 gpm pump. 3/4 is fine for my 11 gpm but won't hack it for that bigger pump. That is the likely cause of the pump cavitation.

 

[LLigetfa]

Is the pump intake above or below the reservoir? Every bit helps so gravity feed is better than suction.

 

[logjammed]

first, thanks for the responses. Today i re-plumbed tank out let to 11/4 to pump (thats the max dia. for this) and the pump still wines very loud. the pump is lower than the tank and about 20" away , also the filter is in the tank return line and is brand new. I let it run for a while ( fifteen minutes ) with no load just circulating and the lines got pretty hot (normal ???) On top of that it would stall my engine at idle when attempting a split. soooo to say the least i am i little bummed now but will persevere as i think i may need a two stage ccw pump. this thing worked great tied to the tractor hydraulics so i no it works. am i correct that the bigger port on the pump is the suction side? flow direction is correct.

 

[brad068]

Jammer, if you can without to much trouble take the pressure side line off the pump either at the valve and dump it back into the tank. It sounds like the pump is "working" like there might be a stuck valve port or relief, in the control valve. That will also tell you if the flow is right.

 

[LLigetfa]

That got me to thinking... if it works on the tractor hydraulics, would that valve be open centre or closed? I thought tractor auxiliary hydraulics need closed centre? Having a closed centre valve would mean the pump is working all the time.

 

[kevin j]

Is the noise less at idle, increasing with rpm? If it is cavitation (or sucking air at shaft seal, two different scenarious but same noises), then at lower speed, less flow, the noise would usually go away.

Is the noise truly at the pump, or at the relief valve somewhere else? The open closed center question referred above. Need a pressure gauge reading.

Why do you think the pump is 17 gpm? When you say truck PTO, was it running at engine speed before, or at a reduced rpm? You may have a pump that was 17 gpm before at maybe 1200 rpm, and you are now engine driving it at 3000 rpm. Does it work at idle without noise? is so, post the engine idle speed, bore and stroke and rod of the cylinder, and cycle time seconds to fully extend. Might find it is way more than 17 gpm.

17 hp will only drive 17 gpm to about 1700 psi best case, or less. So you ar not able to fully utilize the engine hp. even if the suction is not the issue.

I would check the flow and speeds first, I suspect it is way more than expected.

then look for a 22 or 28 gpm two stage pump for sure. Can you drive off the other end of engine? Selection of bigger two stages is very limited. Haldex barnes won;t like belt or chain drives.

You have the power, but a single stage pump won't make much use of it.

kcj

 

[George G]

If the pump is running off the engine crankshaft(CCW rotation), the pump would be CW rotation. The suction side would be the bigger port. The bulk of the pump would be below the shaft. As LLigetfa says, you could have a closed center valve. It should be an open center valve. With a 17 hp motor and 17 gpm pump, you will only be able to run 1500 psi max.

My mistake. I was thinking you were running it off the front of a tractor engine. :red:

 

[logjammed]

At this point i have mulled over replies and did some more thinking and research and believe my best option is a two stage pump and to utilize the engine as current design to run off the front of crankshaft a ccw pump choice appears to be limited to only one haldex option and may be undersized for 17 hp diesel. I will have to do the hydraulic calculator . I will be able to run of the rear of crank if needed. I will also post some more pictures so you can see what i did . it may sound like frankenstien but my powerplant is a toro lawnmower (golf course reel type) and i just cut it up and utilized as much as i could. as far as the ccw pump i tried it was on a ramp truck and the numbers gave me the spec of 17gpm , but no info as to at what rpm and is probably way oversized and verified by# as ccw.

 

[kevin j]

sounds like you have the makings of a really neat machine, based on that engine package. Diesel even.......
Well worth pursing I t hink.

k

 

[logjammed]

decided to go with two stage clockwise off rear of crank and should (better !) solve my problems. just need to get a hub/adapter machined up and lengthen lines from tank. hopeful to be splitting again soon.

 

[kevin j]

I think a better plan all around. With tht engine, depending on your cylinder, I would likely go the 28 gpm pump, At least the 22. Plenty of power to get some speed out of it. You will like the two stage way better.
and let us know if you solve the noise source. I am curious.

k

 

[Gooserider]

Just remember that you want as close to ZERO restriction between the tank and the pump inlet as you can... The suction hose must be at least as large in diameter as the pump inlet, and should NOT have any kind of filter on it. If you insist, one can use a COARSE mesh intake screen, but really all the filtering should be done on the return line going from the valve back to the tank.

It also helps to keep the pump intake lower than the tank full level, if possible. If not possible, keep the pump intake as low as you can, these pumps are NOT designed to pull a lot of suction head. By the same token, keep the suction line as short as possible w/o kinking.

Make sure the suction line is made from a hose that won't collapse under a vacuum - i.e. reinforced like an automotive lower rad hose, or other stiff hose.

Gooserider

 

[logjammed]

well after moving to 28 gpm clockwise rotation 2 stage pump to run off the rear of the crank , I'm glad to say all is well and split for an hour tonight before dark. the unit worked great , it only has to run at idle. the diesel is surprisingly quiet and no more pump noise at all. i will re-check all connections for leaks , change engine oil and filter,fresh diesel fuel, re-fresh hydraulic oil, and attempt to get a full day of splitting all the rounds i have everywhere. four way pin on wedge is being made and log lift maybe this fall.