> -----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
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