Mailing List flyrotary@lancaironline.net Message #18954
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] Re: Electric water pump
Date: Thu, 17 Mar 2005 21:06:39 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
My guess is that the actual 'worst case' in auto use is not at high throttle but at idle on a blistering hot day, stranded in traffic, with the AC cranked full blast.  THAT is when you have the minimum pump pressure and need the minimum resistance to flow.
 
Tracy  (water going through two 5/8" hoses)

    Yeah, I thought Tracy and yourself were using the smaller hoses with the pretty AN fittings, and there is no doubt that Tracy at least has been successful (and I'm sure you'll be right behind him :-), but I still stand by my theory that if the automakers use no less than 1.25" hoses, then why would should we when we have a higher heat rejection requirement.
    Now maybe we can get away with less, but then the argument that the EWP can't possibly have enough flow because of our higher heat output is invalid. Maybe we can get away with smaller hoses, or maybe we can get away with an EWP, but can we get away with smaller hoses AND an EWP???
    Because I knew that many were watching closely as mine was the first known aircraft use of an EWP (some hoping for success and many expecting failure), I decided that 1.25" hoses were mandatory. I'd originally started my installation with 1" hose, but changed my mind on this before I was even completed that part of the installation.
 
Todd

 
If I'm not mistaken, Tracy is using 3/4" hoses???  I've been using AN12 hoses, with two evap cores in series, and there has never been a question of cooling the water on the RV-3, even in severe climb tests.  The antique mechanical pump does have a lot of muscle, and might be making up for it though, and I still haven't found a way to test the EWP by itself in flight.
 
  
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