Ron;
That's a very good question; I haven't seen any reliable test data
comparing plain water with wetting agents or glycol.
Water alone has the highest specific heat (how much heat it takes to
raise its temperature) but it is claimed that a wetting agent improves
the thermal conductivity at the coolant interface. Glycol raises the
boiling point but it lowers the specific heat of the coolant so if you
can run a high enough system pressure it seems like pure water would be
a better coolant, given the same boiling point. Of course the glycol has
some other properties that are beneficial-- corrosion inhibitors, water
pump lubricant, etc.
We used to use water with a high percentage of sodium dichromate
dissolved in it as coolant in Bob's McLaren. It acts as a passivation in
the aluminum block, coolant tubing, etc. Since it was a bright orange
color it was also easy to spot a leak.
Regards, Neil Tucson, AZ
-----Original Message-----
From: Ron Gibson [mailto:rgg14@cox.net]
Sent: Tuesday, March 15, 2005 12:39 PM
To: Albaugh, Neil; Want1937hd@aol.com; edvs@yahoo.com;
land-speed@autox.team.net
Subject: Re: Am I crazy or just dumb?
I would think it would be beneficial to also run some anti-freeze or an
additive to eliminate the surface tension of water for better heat
transfer.
Ron Gibson, Omaha NE
-
There are two things going on-- coolant flow rate and block coolant
pressure. They are inter-related in that as the flow rate through the
system increases, the back pressure in the block increases as well. This
back pressure is due to the coolant's being forced through a
restriction-- a thermostat or restrictor plate. Remove this restriction
and the coolant flow will increase but the back pressure drops. This
lowers the boiling point of the coolant in the heads & block, allowing
hot spots to develop. You need both flow and backpressure which requires
a very good water pump. Check out the Stewart website.
Regards, Neil Tucson, AZ
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