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Horribly vague pump question

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Dodgeboy49

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Discussion starter · #1 ·
Just looking for an estimate of sorts, if possible. I'm helping to build an oversized log splitter using a pump and cylinder taken from a 1950 Ford F-6 grain truck. The truck is long gone, and the pump will be driven by a motor of its own. I'm wondering what the output RPM of the truck's PTO might have been- I understand that it would be expressed as a percentage of engine speed (speed being dependent on the weight of the driver's foot), but was there a percentage that was commonly used in those days?

Of course, given the absolute lack of any details necessary to properly calculate pretty near anything, I understand that this will be a shot on the dark....

Thanks!
 
#2 ·
They don't run too fast at idle, but foot on gas juices them up greatly.--Most truck pumps were rated as "slow speed-high output" type.--I had a 74 chevy c-65 that had the more modern pump and the pto looked to not turn very fast.--I would say probably 1,000 or so. some pumps can sustain high speed short time but not for long hard run.
Was/is the hoist cylinder a double acting? (power both ways?) or just single acting!--Single acting will only push and not pull back for another stroke without some sort of heavy spring.
Also is the pump seperate from the cylinder??--Most old Anthony or Heil type hoists were pump/valve/cylinder as 1 unit!
See if youcan answer these questions, then we will go from there!! thanks; sonny
 
Discussion starter · #3 ·
The unit is made by Schwartz Manufacturing in Lester Prairie, Minnesota. The cylinder, pump, and reservoir are each separate from one another. The pump has two hydraulic lines and a cable-operated valve in it. One of the lines goes directly to the lower end of the cylinder and the second line goes to the reservoir (which doubles as a crossmember for the scissor lift). From there, a third line goes to the upper end of the cylinder, which also has a threaded plug which I assume to be for filling or bleeding the system. It has been nearly twenty years since I last ran the truck but I sure thought it had both power up and down, but that would mean pressurizing the reservoir on the down stroke which doesn't seem right to me.
 
#5 ·
The top hose would vent back into the tank! plug is bleeder---Now Schwartz made rollback beds way back when, and they may have used a 2-way on your hoist, (co. might have done this at the time because they only had 2-way units in stock).----Yours is now set up as one-way.---You can test the 2-way possibilities by hooking the cylinder to a TWO way valve and see what happens.---You do take a chance of blowing the piston IF I am wrong!--You could also take the cylinder end off and pull rod and piston out and check for sure.

I read and re-read!!!! your post!, The setup is odd, but I still think you have a 2-way cyl. plumed as a 1- way, and as you say tank pressure could have provided a bit of down pressure!
If it were me I would hook it to 2-walve and see what it did.---CAUTION!!!!--- Don't stand near it IF you try this!!!!

I have a Glencoe hoist, but it is twin cyl. and they are positive 1-way as most hoists were/are! thanks; sonny
 
#6 ·
You can't pressurize a reservoir without a second pump and another reservoir.

As a rule, reservoirs are vented to allow for the difference between the volumes of the cylinder on each side of the piston, and to accommodate expansion due to heat.

Compare the rod diameter to the cylinder diameter. A one-way cylinder will have a rod approximately 1" +/- smaller in diameter, while a 2-way cylinder will have a rod about 1/2 the diameter +/- of the cylinder.
 
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#7 ·
If its a closed system, the oil will move the same amount in each direction. It don't really provide true pressure other than the oil weight. I had an old hoist set up this way back in the ice age. the cyl. was 5" and had 2" rod.as was most old anthony and heil hoists. thanks; sonny
 
Discussion starter · #8 ·
The venting is an interesting thought. As it sits now, there are no vents anywhere in the system; however, we were surprised at how little oil we drained from it considering the anticipated volume. Must've needed the extra space for expansion. There are additional plugs in the reservoir, one of which was probably a vent originally.

We also noted the fact that the pump is painted green while all other parts of the system were painted red, which would support your theory that the system was altered. Considering the fact that the exhaust system on the truck was made of threaded drainpipe, I would find it likely that a previous owner was accustomed to fixing it with whatever he had on hand.

My dad has another old grain truck, still operable, that we know has a one-way system. How do we know? If the load don't come out, the bed don't come down, and then the shovels come out...

I'll check your ideas when I next go out there; thanks for the help!
 
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Dodgeboy49
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