To Henry and all
You missed the point of my reply and that is OK because you have
added good information to the discussion.
We were given a general statement; "My buddys car has chronic overheating
problem", no specifics, no details and he was ready to spend $200 on a new
water pump. My reply was also general and I hoped to make them think about
the problem instead of just throwing money at the problem.
Overheating is a system problem and the whole system needs to evaluated.
The problem could have been a $5 thermostat or a $10 radiator hose.
My point is check everything first. A stock engine will run fine with a
stock water pump; if that engine overheats, I generally look at the other
components in the system especially the thermostat. Water pumps usually
make all kinds of noise or leak coolant when they fail.
As for my statement; it might not be completely accurate in all
incidents but it is essentially true.
We can not change the laws of Physics or Thermodynamics. Every coolant has
a heat absorption rate; the faster you move the coolant, the less time it
has to absorb heat and less time to release the heat. It's one of those
trick questions that you really can't answer correctly without all the
specific information, which is not available to us here and this is not
Thermodynamics class.
Its been 30 some years since I opened a Thermodynamics book and I
know there are many many factors involved for the Heat absorption and Heat
dissipation equations and there are even more factors to consider when your
dealing with a closed system. Again that was not my point.
System problems need the whole system evaluated to find the root
cause of a problem; especially the cooling system.
Ron Fraser
-----Original Message-----
From: motoys2001@comcast.net [mailto:motoys2001@comcast.net]
Sent: Sunday, July 09, 2006 2:13 AM
To: Ron Fraser
Cc: tigers@autox.team.net
Subject: RE: water pumps
"A problem with higher flow pumps is the higher and faster the flow through
the block the less time the coolant has to absorb heat, so you could have a
worse overheating problem."
Ron and Listers,
The above statement cannot be any further from the truth! Please, please,
please everyone raise your right hand and PROMISE to rise above this
nonsense of and urban myth and commit the following to memory...
Here is the link to the Stewart Components Tech Pages that explains why you
want high flow and high pressure:
http://www.stewartcomponents.com/Tech_Tips.htm
The automotive cooling system is a closed loop. A higher pressure in the
loop and a higher flow through this loop
will yield a more efficient exchange of btu at the radiator. Adequate air
flow across the radiator will transfer the btu out of the loop to the
atmosphere.
Limitations are the burst pressure of any of the cooling system's components
(the radiator cap in a well designed system should prevent this), the
efficient
unrestricted flow of water through the system, and the efficient
unrestricted
flow af air across the radiator.
Lots of h2o pressure, lots of h2o flow, lots of air flow across radiator is
good!
In a nutshell, slowing down the water flow to extract more heat is dead
incorrect.
Henry V
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