Mailing List flyrotary@lancaironline.net Message #2817
From: David Leonard <Daveleonard@cox.net>
Subject: RE: [FlyRotary] Re: water flow restrictor
Date: Sun, 7 Sep 2003 09:37:56 -0700
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On
Behalf Of Al Gietzen
Sent: Sunday, September 07, 2003 8:43 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: water flow restrictor

Subject: [FlyRotary] water flow restrictor

Although I would probably prefer to run a thermostat, my water pump
housing lost the ability to house a thermostat when it got chopped
down
to size.  Do I need to put in a restrictor?  If so, how big should the
opening be?

David Leonard

Putting  flow restriction in an aircraft application where you want
minimum radiator size and weight is a bad thing; in my opinion, of
course.  The more flow the better - gives a lower temperature drop
across the radiator, therefore higher average radiator for the same
temp
going back to the engine.

The idea of a flow restrictor is to provide higher pressure in the
block, therefore increasing the boiling point somewhat; and provides
back pressure to the pump which may reduce the risk of cavitation at
very high rpm (like over 6000).  If you don't mind a larger radiator,
OK.

Size the radiator for about a 30F drop from inlet to outlet. Let the
radiator provide the back pressure in the loop, maybe take advantage
of
double pass.

Al

Thanks for the advise, Al.  I understand about using the smallest rad
that will work, but that still doesn't address the issue of increased
boiling point (for micro bubbles I assume) or cavitatation.  Are these
an important issue???

I do have a double pass thin rad, not sure if it will provide enough
restriction  Also, the water supply for the turbo comes from the block
and I'm afraid that if I remove the restriction of the thermostat then
the flow through the turbo will be reduced.

I guess no one can answer these Q's for me for sure... I'll just say
'experimental' 3 times..  Thanks

David Leonard
The Rotary Roster:
http://members.aol.com/_ht_a/rotaryroster/index.html



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