Bonneville America Forums Forums Technical Forums General Tech Radiator coolant, MAYBE.

Here's an interesting read from July, 2013 issue of Hot Rod Magazine.

Complete article:

Glycol or Water: Which is the Better Coolant?
The specific heat capacity of ethylene glycol-based water solutions is less than that of pure water; in a 50% solution, ethylene glycol's specific heat capacity compared with pure water is DECREASED at least 20% at 36 degrees and about 17% at 200 degrees. Propylene glycol, another common coolant, has an even lower specific heat. Assuming a 100-gpm (gallons/minute) coolant flow rate and an energy loss through the coolant system of 189.5 hp, the water temperature increase would be 10 degrees, the ethylene glycol water mix would gain 20 degrees, and the propylene glycol would gain 33.3 degrees.
Compensating for the reduced heat capacity of coolant/water mixes would require circulating more fluid through the system. Assuming a fixed amount of circulating fluid and radiator capacity, running 100% water would be the most efficient coolant in terms of it's ability to conduct heat with minimal temperature rise. In other words, of all common liquids, water requires the most heat energy to change it's temperature.
However, there are also differences in the vapor point of the three different coolants. Ethylene glycol and propylene glycol have higher vapor points and therefore can absorb heat at higher temperatures without boiling. Yet even with it's lower vapor point, water STILL carries more heat per unit.
Don't forget that the coolant is just one part of the cooling-system "team". You can raise water's effective vapor point by using a higher-pressure radiator cap. For every pound of increased system pressure, water's boiling point goes up by 3 degrees. Higher boiling points also reduce evaporation losses, water-pump cavitation, and heat-soak-induced after-boil. You can get away with a higher system pressure by using a quality aluminum radiator that's rated for higher pressure than is a brass/copper radiator. Aluminum radiators can take more pressure because their tensile strength is greater than brass-this lets an aluminum unit use tubes with larger cross sections and thinner walls. A larger tube also has more wall-surface area, resulting in improved heat transfer.
Bottom line: A large-tube aluminum radiator filled with pure water and using at least a 20-psi cap is BY FAR the best heat-transfer setup, provided the vehicle is not subject to freezing conditions. Be sure to add a corrosion inhibitor when running pure water.

HOTROD.COM/ Marlan-Davis



I can testify to this, as living in Florida all my adult life, my vehicles are filled with water in aluminum, four-core, high performance radiators with 16 psi or higher caps. I've only had to drain my radiators/block about once every 5-10 years due to extended (five or more hours) temp's below freezing. Not that hard, get motor to operating temp and open the radiator drain petcock. When the 6:00 am warm-up hits, re-fill, warm to operating temp., and recheck after burp. Again, once in 5-10 years.

Of course, this info. is useless to anyone further north than Ocala.

Nah, I'm just gonna put FINS on EVERYTHING!

Well, NOTHIN' could do THAT. But it would eliminate ONE rant.

Actually I think it would just encourage him even more.

I think it was always called antifreeze because it prevents the water from freezing at low temps. I dont think it has anything to do with improving any cooling ability. I use to always run water in the summer and add antifreeze in the winter when I lived up north.

I guess I've always thought water boiled @ 212F in an open pan,
When it appears that was the boiling point I've been taught in auto class (MANY decades ago) for a standard auto radiator.



The older I get, the more often sh1t like this happens.

Doesn't change the facts in the article though.
Thank God it was written by someone presumably younger than I.

WAIT JUST ONE MINUTE HERE!

What's up with that chart!???

According to it, water will boil @ 80F with no pressure (0.5psi).

How come my spa, tub, and dish washing water ain't boiling at all times? Their over 100F straight out of the hot water tank.

Or was it 100C = 212F ?

Now I can't sleep.

Kidding? No.

Just trying to see if that chart from engineeringtoolbox Included standard atmospheric pressure in their graph, or not.

And yes, water usually boils @ 212F, AND 100C = 212F. NOW it comes back to me that the boiling point (and freezing point) of water is what the Celsius temp's were based on in the first place.

(Regular fire, paper, starts about 451F.)

http://www.youtube.com/watch?v=NBh895KdXAU

Ok now we all the informatiin required to caise a tremenous amount of trouble. So lets design a new liquid cooling system for air cooled motors. We could sell it as a chromed shiney doodad for the gold fish, I mean Harley riders.