"Ned Simmons" wrote in message
...
In article gIw_c.2426$j62.422@trnddc04,
says...



I've got a little pump-dyno here where I mounted the pump so it is
free to
rotate. Then, when the flow is restricted, the pump tries to rotate.
When I measure the torque imposed on the pump and the shaft RPM, I
assume I
can calculate HP with Excel. But, the idea of several GPM at a thousnd
+
PSI scares me enough that I dont want to test it in the garage. I
might
get courage to test it on a fractional HP motor. All the other dyno
loads
I've tried get too hot when loaded for even a few minutes. Water spray
helps extend the test run time, but even the water makes a little mess.

Jerry

If the hydraulics are done properly I wouldn't be too
concerned. I've got the schematics here for a 100 HP test
stand I designed and built for one of the big hydraulics
mfrs. for testing high speed hydraulic pumps and motors. As
well as testing both pumps and motors, it checked
volumetric efficiency and went thru an automated sequence
while logging data, so I'm sure it's much more elaborate
than what you've got, but if you're interested in the
schematics let me know.

Ned Simmons

Ned

My problems are associated with a poor decission I made in the design of
this little dyno. I wanted the drag on the load's rotation to be minimal.
So, I made the lines into and out of the pump as flexible as possible. I
thought the output hose could be "light weight" because it is such low
pressiure. My brother-in-law spent his life designing hydraulics for
Northrop. He told me storries about high pressure liquids punching small
holes in outlet hoses due to some caracteristic of high pressure pumps. I
thought -- Oh Sh*t. Since I have other things to occupy my time, I dropped
that dyno for a while.

I appreciate your offer to share your dyno information with me. I wish I
could get involved with a project that uses a big dyno.

What kind of instruments do you use to log the data. I got a Lab Jack but
get confused about how to use it.

Jerry.