I am building a test set using my CC mill as a power source. I will be
able to
run the pump up to 7000 RPM and drive it with a 2 HP mill motor.
I don't think a single V belt will transmit that much HP so we shall
see. I have an eight inch die cast drive pulley and that might not
do the job so I am thinking of adding another one and use two
belts to drive the pump.
Bill Schertz ran the pump up to 5600 RPM and I am interested in seeing
what happens after that. I am also interested in seeing if the new
housing casting pumps more water at the same RPM as I think it will.
I also have an optical tach so I can check the pump RPM accurately.
Paul Lamar
BTW if anybody wants to do a little research on their own cooling system
McMaster Carr has a low cost ($65) flow meter that can be installed
in a working system. You drill a small hole in a 1.25 inch OD
water pipe and insert a small pito tube. The flow meter is then
clamped on the pipe with a gasket and hose clamps to seal the small hole.
This device measures the flow from 15 GPH to 75 GPH. This low cost flow
meter is not too accurate at +/- 10% but could provide far more info on
a real working system than we have now. If you plan on trying this please
measure the pressure in the block just before the exit, after the
thermostat
and on the inlet side of the pump to get a complete picture of what
is going on. The flow meter can go anywhere in the system as the
flow rate is the same throughout a closed loop system. If the passages
neck down the flow speeds up. If the passages open up the flow slows.
BTW Using a drum of water and a bucket to measure the flow does not really
simulate a real closed loop working cooling system. Never the less
Bill Schertz work using this method is greatly appreciated as it is way
more info
than we had before. Here is the results Bill Schertz got with an
open loop system.
Paul Lamar
Paul,
You are absolutely correct that doing it open loop with a drum of water is
not quite the same as a true closed loop system, however that is why I
measured the pressure at the inlet to the pump as well as the outlet. The
difference between the curves is the total pressure available to pump
through the radiator. Using a flowmeter should give much more consistent
runs, and be a LOT less messy.
I tried using an optical tach for my last set of runs, but since it was
winter and I had to keep the door closed on the hanger, I found that the
flourescent (and even incandescent) lights overwhelmed the tach and gave me
the constant 'calibration' rpm. The only way I could get it to work was to
turn off all 60 cycle lights, and use a flashlight to illuminate the
aluminum foil band on the water pump housing. Too much trouble! Being
summer, you can just use daylight.
Anxious to see your results. All my data, of course INCLUDES the pressure
drop from going through the engine.
Bill Schertz
I was thinking of simulating the pressure drop in the engine with
a restrictor. Did you get any comparison pressure drop on the engine
verses the pressure drop in the rad? I can also pressurize the closed
loop system with a shrader valve to see if that has any effect.
Paul Lamar
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