I hope there is someone out there who can tell me if I have what I need.

I did some rudimentary pressure and flow tests on this home made waterpump 
that is designed to bolt directly on the e-shaft.

Zero flow pressure, starting at 1065 rpm was 2.5 psi, increasing as rpm 
squared up to 80 psi at 6000 rpm.  

Flow rate with a 2.25 foot lift required on the intake side, zero back 
pressure, starting at 1065 rpm was 15 gpm, increasing linearly up to 40 gpm 
at 2520 rpm.  Almost no increase in flow rate above that up to 6000 rpm.  
However, at 3840 rpm, restricting the output until there was a 20 psi back 
pressure did not change the flow rate. 

Previous testing with only a 8 inch lift at 2600 rpm resulted in 50 gpm.

It looks to me like, with that much lift, I am intake limited.  On an engine, 
there will be no lift, and the system will be under pressure so I will give 
it a try.

I need expert guidance here--what am I overlooking?

Thanks

Bob Darrah

(1) The supply lower than the pump.

(2) The supply not pressurized to replicate an operating system.

(3) The supply not heated to replicate the worst case condition.

(4) The supply suction tube possibly not radiused (square cut), reducing
effective  diameter by 2/3rds

(5) The system not a closed loop to replicate an operating system.

On the up side: you are experimenting and building up a new system, It's far
cheaper to discover cavitation on the bench rather than some other locations
(altitudes). Mix in some glycol, and maybe some Redline "Water Wetter",
pressurize the system as high as you dare, play with the restrictor size and
keep going. The crank speed pump should help with the ground overheating
problem and pump speed at cruise shouldn't be a problem.

Lynn E Hanover

 
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