<... stock pump with the EWP in a given system ...>
I'm not trying to compare a particular EWP with stock under any particular
conditions.  I'm interested in determining the *requirements* of the engine
under as many conditions as possible.  I figure that it will involve a
thermostat and a coolant flow measuring device.  Absent a thermostat, we don't
know how much more coolant we're pumping than is necessary.  With a thermostat
maintaining temperature, we are much more assured that the flow observed is
exactly what is needed for proper heat rejection under those circumstances.

I don't believe that pressure drop helps much, if for no other reason than that
a small (read difficult to measure accurately) error in pressure drop would mask
a large flow difference.  If we measure flow directly and accurately at the
temperature we want to maintain on the engine, we can search for an EWP that
meets those requirements and our questions are pretty much answered.  I believe
that a thermostat and a flow meter are pivotal and would personally be reluctant
to proceed without them.

Just a theory .... Jim S.


Tracy Crook wrote:

> > Posted for Jim Sower <canarder@starband.net>:
> > I don't think we can estimate squat.  If we could find a coolant
> > flow transducer in a maybe 35-40 mm line, Tracy and Ed could
> > patch it into their radiator hoses and measure what the
> > by-gawd-for-really flow is under various conditions.  That done,
> > it would be simple enough to get some various EWPs patched into
> > the system and find out just how much electrical power it takes
> > to generate that flow.  For the reference flow figures, the
> > airplane would have to be flying under the conditions tested.
> > For the EWP test, the engine wouldn't even have to be running.
> > Simple as that (not to be confused with easy ... :o)
> > Just a theory .... Jim S.
> >
> >
>
> To compare the stock pump with the EWP in a given system you really don't
> need a fancy flow meter.  Just measure the pressure drop through the system
> with a pressure gauge between pump outlet and after the rad.  The higher the
> pressure, the higher the flow is.
>
> Tracy Crook
> tcrook@rotaryaviation.com
> www.rotaryaviation.com
>
> >>  Homepage:  http://www.flyrotary.com/