On Sunday 23 October 2005 01:46 pm, Dave1massey@cs.com wrote:
> The concept that water moving too fast through the radiator will result in
> less cooling is an urban myth.
You are right. Muddleheaded thinking on my part. I was thinking more along the
lines of too big a pump and the problems related to that, like cavitation.
Moving the water faster through the radiator is a useful way to increasing
turbulent flow (good for heat transfer) and decreasing laminar flow (bad for
heat transfer) in a properly designed system. Basic physics tells us that the
higher the flow, the more heat will be "moved".
There may be a simpler, easier "fix" for most people that live in warmer
climates and that is to improve the ability of the coolant to absorb heat at
a faster rate.
To do this, use distilled water with as little anti-freeze as possible,
certainly less than the 50/50 mix assumed to be standard. The anti-freeze
manufacturer provides a table to determine how much to use. Go for the
minimum.
_Some_ amount anti-freeze is useful only because it contains chemicals for
lubrication and anti-corrosion and it does raise the boiling point of water
somewhat (as does using the correct pressure cap on the radiator). You can
purchase the "good stuff" that is in anti-freeze without the glycol itself if
you'll _never_ drive the car when the temperature is low enough to freeze the
water. If you're comfortable with this and only drive in the summer, use this
stuff and distilled water only; no anti-freeze at all.
Products like "Water Wetter" are surfactants that reduce the surface tension
of the coolant which helps remove air bubbles and reduce any tendency for
cavitation. It's a useful additive for that purpose, but if it causes a drop
in temp consistent with the manufacturer's claims, you have other cooling
problems. 8)
Two last overheating tips:
Don't paint the radiator heavily. Paint is an insulator and the radiator only
needs a very light coat for cosmetics (and some surface corrosion resistance,
I suppose). I see too many cars with beautiful engine compartments and
radiators with thick coats of shiny black paint. This is great only if the
car lives on a trailer.
Check the distributor advance and carburetor adjustment. An incorrect setting
at idle will raise engine operating temps.
--
Hoyt
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