Subject: Bulents 13B Cosmo water pump.
From: Paul
Date: 7/13/2000, 3:46 PM


Cooling systems don't carry watches.  They know nothing about time!  If
you
increase the flow and it cools worse then something else bad happened
(like
removing the thermostat on a 13B and feeding the water into the pump
instead of the rad)  Another possibility is that the water is boiling in
the block due to excess heat for a given pressure and the back pressure
is
controlling boiling.   If so then get a higher pressure cap and let it
flow.  Don't back pressure the flow to cover up some other problem.
Pumps
don't "need" back pressure.  That's pure folklore.

Jeff Spitzer

That is worth repeating. "Pumps  don't "need" back pressure."

Paul Lamar



Tracy Crook wrote:

It is true that a pump does not "need" to be designed to have back pressure.
BUT, if it  *is* designed to work with back pressure (and there are lots of
reasons to do so) then operating the pump without that required back
pressure will result in cavitation, less flow, and pump damage.  This was
shown quite clearly on some of the information previously posted.    Anyone
who has worked on their own well pump is familiar with the "churning gravel"
sound of a cavitating pump when the pressure is too low.   If the water pump
output is visible (like in my lawn sprinkler system) the loss of flow is
directly visible.

I'm amazed Jeff.  Did you really mean that statement as unconditional?

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

 
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