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Date: Sun, 07 Nov 2004 10:07:45 -0500
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: EWP Info
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Russell Duffy wrote:
> I see several possible advantages to the dual pump setup.  Maybe I can turn
> one off for curise which would save current draw. 
> 


Just a word of warning.

Don't do this with ambient air below freezing!!

You've got a radiator full of water sitting in a freezing airstream.  If 
you switch off the flow for any significant amount of time, the water 
will be very hard when the second pump tries to switch back on.

Maybe the problem can be avoided by:

1) lots and lots of antifreeze?
2) some sort of flap/door/covering to close of the radiator that is not 
in use?
3) a 'weep hole' in a flapper valve that will allow a minimum amount of 
flow to keep the water liquid?
4) ???

-- 
http://www.ernest.isa-geek.org/
"This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."