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Date: Sun, 7 Nov 2004 09:37:53 -0700
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: EWP Info
Message-Id: <20041107093753.6d19fffc.bob@bob-white.com>
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Thanks Bill,

One question.  Did you have a thermostat in the engine when you did
these measurements?  That would effect the pressure and flow rates.

Of course what I need to know is how much flow is sufficient for full
power cooling.  If I take the crossing point of the 'two core' data and
the 5594 RPM data as an indication, it looks like around 9 psi and 33
GPM is what the factory pump is providing.  This should be similar to
Tracy Crook's situation.  Am I looking at that correctly?

Bob White

On Sun, 7 Nov 2004 09:09:56 -0600
"William" <wschertz@ispwest.com> wrote:

> Bob,
> Attached is a graph of the performance of a Mazda mechanical pump at
> different rpm. Several things about the performance can be deduced.
> The measurements were taken by pumping water from a barrel through the
> engine and back to the barrel. Flow was measured by the time required
> to fill a 5 gallon bucket, and pressure drop was measured into and out
> of the engine water pump.
> 
> First, at zero flow, the pump is generating its maximum pressure. At
> zero pressure, the pump is generating its maximum flow. Since the
> measurements are made at the inlet and outlet of  the pump, the
> pressure drop of the engine core is included. If you look at the three
> rpm curves, at 2448 rpm, the pump can generate just under 5psi head,
> and a no head flow of ~20gpm. this means that the pressure drop
> through the core is 5 psi at 20 gpm.
> 
> At 3730 rpm you get 8.5 psi and 33 gpm, at 5594 you get 19psi and 44
> gpm.
> 
> I also measured the pressure drop across GM evap cores as a function
> of flow. Data is plotted on the curve.
> 
> Bill Schertz
> KIS Cruiser # 4045
> ----- Original Message ----- 
> From: "Bob White" <bob@bob-white.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Saturday, November 06, 2004 9:39 PM
> Subject: [FlyRotary] Re: EWP Info
> 
> 
> > On Sat, 6 Nov 2004 20:52:55 -0600
> > "Russell Duffy" <13brv3@bellsouth.net> wrote:
> >
> > > Hi Bob, somehow these numbers do not pass the "smell test". There
> > > is no way you can pump 20 GPM with the back pressure in the system
> > > on 5 Amps alone. Larry's observations below make sense. A little
> > > air blower motor moving air uses 5 Amps. Bulent
> > >
> > >
> > > Hi Bulent,
> > >
> > > You're starting to sound like a disbeliever.  We're not going to
> > > have to banish you to the other list are we :-)
> > >
> > > Rusty (I believe)
> > >
> >
> > Now now!  Let's not have any banishing around here. :)
> >
> > I don't know what the numbers mean but I will let you know how it
> > works out.  Todd reported his pump measured 4.3 amps at 9.3 gpm (if
> > I understood his last post).  Mezarie may be reporting the "no load"
> > pumping capacity, or Summit may have the current wrong.  I should
> > have the pumps sometime next week.
> >
> > Any idea what a ball park figure for the pressure drop across the
> > engine and an evap core would be?  I could simulate it on the bench.
> >
> > Bob White
> >
> >
> > -- 
> > http://www.bob-white.com
> > N93BD - Rotary Powered BD-4 (soon)
> >
> > >>  Homepage:  http://www.flyrotary.com/
> > >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
> 


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