Hi Bob,
Another aspect that I recall when I bought my original '63 Corvette
Coupe (and also all of the Corvettes that we serviced that were equipped
with aluminum radiators) was that glycol based/mixed coolant had a
quality of suppressing galvanic corrossion or made the resulting mixed
solution less "conductive".
Does anyone on the list know if this is further "urban auto legend" or
know of a more accurate set of facts relative to this question. Even
better - the correct explanation would be welcome.
Regards to all,
Don Cordier
(1968 Lotus Elan S4SE Coupe - S/N 36/7947 - Cal License "68 Lotus")
Pictures (courtesy of Alan Perry) at:
http://www.best.com/~esprit/elan.html
(1963 Corvette Roadster - VIN: 30867S116306 - CA License "QAM 488")
Aviation Consultant
Glendale, California, USA
doncordier@earthlink.net
Office & Hangar: (818) 997-7640 (24 hours)
FAX-Private: (805) 527-1034
FAX-General: (818) 553-3667
Member: NBAA, NATA, PHPA, AOPA
Bob Palmer wrote:
>
> Dave, et Listers,
>
> I still stick by my previous story on this subject. One question you can
> ask yourself is what do most auto manufacturers put in their new cars? Most
> of these car manufacturers are not like Brad Parlee, "just looking for a
> way to spend more money" when they fill their radiators. In fact, these
> guys wouldn't part with a nickel they don't have to. If distilled water,
> even with additives, actually worked as well as water/glycol mixtures I'm
> pretty sure that's exactly what they would be using. BTW, does anyone
> happen to know the prescribed mixture for any standard production car? From
> what I've seen, they must use at least a 50% glycol. Now certainly factors
> included in the choice of coolant includes corrosion and, yes, maybe they
> want to be able to sell you coolant at $5 a gallon instead of letting you
> just fill it up with water. But the manufacturers have performance
> standards that have to be met, and using a less efficient coolant would
> mean having to compensate with a larger (more expensive of course)
> radiator. Not a smart economic tradeoff I think. For most racers, the use
> of glycol coolant is prohibited and straight water works quite well enough.
> They usually use additives like water wetter and higher pressure caps to
> help compensate. Besides, if your engine gets over 245 degrees, it's
> probably time to pull over before you do some real damage anyway.
>
> Incidentally, I believe if memory serves me, that it is the heat capacity
> of water that is 2.4 times that of glycol, not the thermal conductivity. In
> any case, the thermal conductivity is a very minor parameter, much less so
> than the heat capacity.
>
> Taking a sharp detour to another remotely related subject, I ran across an
> empirical formula for calculating horsepower based on quarter mile speed in
> a car magazine recently and thought, if you haven't seen it, you might find
> it useful. Here it is:
>
> h.p. = (q.m.speed/234)^3 * weight
>
> For example, if your car does 105 mph in the quarter mile and weighs 2600
> lbs, then:
>
> h.p. = (105/234)^3 * 2600 = 235 horsepower
>
> They didn't say, but I assume from the answer that they mean net horsepower
> at the rear wheels. So, save yourself the trouble and expense of a chassis
> dyno and go run a quarter mile and not only get the answer, but have more
> fun to boot!!
>
> Bye for now,
>
> Bob
>
> At 07:24 AM 9/24/98 -0700, Dave Binkley wrote:
> >Saw the following in the May 98 issue of Car Craft and have been meaning to
> >post it. The recent postings reminded me to go dig the mag out and send
> >this along. The article was entitled the "25 Lies Car Magazines Have Told
> >For Years".
> >
> >"Lie Number 9: Glycol-based antifreeze is the best engine coolant. The
> >Truth: Plain water is the best coolant. Water has 2.4 times greater thermal
> >conductivity than conventional ethylene-glycol-based coolants. Glycol is
> >also much more viscous than water, and the more viscous the medium, the less
> >the heat transfer rate. Glycol has a higher boiling point than water, but
> >even when using a 50/50 water/glycol mixture with a 15-psi radiator cap,
> >glycol's boiling point is only 15 degrees more than plain water. If you
> >have a marginal cooling street car, try reducing the amount of glycol
> >antifreeze in the system and increasing the water content. A 33 percent
> >glycol/water mix won't freeze until 0 degrees F. On a race car or street
> >car not subjected to freezing temperatures, consider running only water as a
> >coolant."
> >
> >They go on to mention how ordinary tap water is extremely corrosive and try
> >to use distilled water.
> >
> >Dave
>
> Robert L. Palmer
> Dept. of AMES, Univ. of Calif., San Diego
> rpalmer@ames.ucsd.edu
> rpalmer@cts.com
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