Andrew B. Lundgren wrote:
>
> I picked this up on another car list I am on. I found it
> interesting.
>
> >> 'Jim Crider wrote'>>
> "Here's a response from someone who designs vehicle cooling systems
> for a living (that would be me):
> Strictly looking at the heat transfer coefficient, straight water is
> the way to go. HOWEVER... straight water has its problems, notably
> a lack of certain additives that prevent cavitation of the water
> pump at high speeds, corrosion of the various metal bits present in
> all engine cooling systems, surfactants to lower the surface tension
> of the coolant (allowing it to "wet" the surfaces of the coolant
> passages better) and anti-foaming agents to keep the surfactants
> from making big bubbles.
Interestingly enough, an article on "Glycol Coolants" has appeared in
the latest edition of the magazine of our national motorsport body, CAMS
(Confederation of Australian Motorsport.
CAMS is considering a total ban on glycol based coolants for races (with
some exceptions). I could reproduce the total article here, but won't
unless requested :-)
Some of the good points of glycol have been repeated in the article as
in this Andrew's post but the primary reason for considering the ban is
contained in the following:
"The stuff is just plain slippery.
Drop water on the track and it dries quickly. Drop glycol on the track
and it dries more slowly and then leaves a residue which can become like
oil the next time it rains. Motorcycling and karting bodies around the
world prohibit the use of glycol for this reason and the bike fraternity
in Australia must wonder how wise it is to use tracks like Phillip
Island after the cars have been on it."
The article mentions why glycol was used in the first place and the pros
and cons of using it (less efficient than straight water but boils at a
higher temperature and freezes at a lower temperature; less corrosive to
aluminium components, unless it is not changed regularly and the glycol
content falls below 30% at which stage it can produce its own corrosive
byproducts; etc.).
So it seems that Ethylene Glycol is on everyone minds at the moment.
CAMS are taking submissions at the moment, before they decide on a ban
or not.
Eric
'68MGB MkII
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