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From: "george lendich" <lendich@optusnet.com.au>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-1230912@logan.com>
Subject: Re: [FlyRotary] EWP Power - Was: Re: Nothing to do with Rotary Engines, but....
Date: Tue, 11 Jul 2006 07:44:37 +1000
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Thanks Bob,
George ( down under)

> I don't think so George.  The power consumed by the mechanical is
> around 2 hp.  The electric wp is running around 1/4 hp max.  This
> difference is way to much to be attributed to any rating difference
> between the two.  The 2 hp was measured by Paul L at a pump speed of
> 7000 rpm.
>
> My theory is the mechanical pump is designed to provide adequate cooling
> on a hot day in stop an go traffic and as a result consumes more power
> than required at high power.  The power required by the pump increases
> as the cube of the rpm, but the flow is proportional to rpm.  So if the
> engine goes from 800 rpm to 3000 rpm, the power used increases by a
> factor of 50.  My pump is drawing 12-13 amps at 14V or almost 1/4 hp.
> I'm using a Mezerie pump.  The Davies-Craig pump seems to produce
> about the same flow with less current.
>
> I also think the EWP is somewhat marginal or inadequate for continuous
> high power.  The only data point I have for my system is that on a 60F
> day with no cowling my oil and water temps stabilize at 190-200F up to
> 4000 rpm or so.  I ran it up to 6000 rpm for short periods of time and
> the temps started creeping up.  The one time I couldn't maintain those
> temps was on a day when the wind was blowing 30 mph and I turned
> downwind.  I was taxiing about 10 or 15 and the temps started up
> immediately.  After turning back into the wind, temps were running
> lower than normal.  (so the WP doesn't do any good if there's no air
> flow) :)
>
> I'm almost finished with the cowling work so I"m looking forward to
> finding out how well it cools on a 90F day with the cowling on.  That's
> assuming I can get everything finished up before it turns cool again. :)
>
> Bob W.
>
>
> On Mon, 10 Jul 2006 16:29:30 +1000
> "george lendich" <lendich@optusnet.com.au> wrote:
>
> > I'm wondering if any of this sort of information is relative
> > (donkey reference aside) to use of electric water pumps and how they run
with reduced HP but seemingly provided  sufficient coolant transfer, even if
they appear borderline power wise.
> >
> > George (down under)
>
>
> --
> http://www.bob-white.com
> N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
> Custom Cables for your rotary installation -
> http://www.roblinphoto.com/shop/
>
> --
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