Coolant II

[Been Here Before]

Coolant II

The question of how Antifreeze - glycol - is to be used for cooling is going to be open. As I stated I have used 100 % green antifreeze - ethylene glycol for a coolant. As I live in a region where it does not get extremely cold and the car is parked indoors in the winter, freezing is not an issue. But cooling is - straight glycol works to keep the motor from burning up.

The following is from a F1 site. https://www.f1technical.net/

"Glycol transfers heat more efficiently than water and raises the boiling point. You could go with a 100% Ethylene glycol coolant systems, like they did on the early RR Merlin engines, but that had a greater risk of fire and was more prone to leaks. When they could improve the cooling sufficiently to introduce a 70% glycol/30% water mix it solved various problems associated with using glycol by itself (I think that's when they started pressurising the coolant as well). If you went to water only, you'd need bigger radiators. "

For more see:
https://www.f1technical.net/forum/viewtopic.php?t=28740

Discuss?

[Scott_Conger]

You may find a website with an opinion that ethylene glycol is more efficient than water, but that does not make it so. There are considerable caveats which are involved to reach that tortured conclusion and absolutely none of them involve cooling at atmospheric pressure and without a water pump. Whether or not it is more efficient has everything to do with the design of the cooling system, and though I do not know the details of RR Merlin engines, I suspect that they are a little different than a T engine and it's cooling system. As a mixture with water, depending on it's concentration, ethylene glycol is 5-10% less efficient than water alone. The specific heat of ethylene glycol is LESS than water and for equal results, the circulated volume must be increased for it to equal that of pure water. At temperatures above 36F, 50:50 mixture the specific heat capacity is reduced by 20% over that of water. It is simply science. That said, the constant and now frequently fatal damage that water has done to 90+ year old blocks does not suggest that the best coolant (water) is the best choice for block longevity.

Running completely pure, undiluted ethylene glycol coolant in your T, or any heat exchanger will result in approximately 35% loss in cooling capability over water. If that works for you or anyone else, knock yourself out.

With a T, the key to cooling is threefold: you must have a medium which will change in density sufficiently to automatically siphon in the engine within an acceptable temperature range, and have the heat absorption capability sufficient to pull heat from the engine and dump it to ambient air, and finally, a radiator with sufficient condition and capacity to dissipate the heat.

[Been Here Before]

Hi - Scott Conger: Truce?

[Norman Kling]

I don't know all the scientific reasons for the specific mixtures and various types of anti-freeze. I live in an area which seldom has below freezing temperatures, however, I find the cooling system works very well and has fewer problems with a 50 50 mixture of pure water and green anti-freeze. We do have some summer days where it gets over 100F and have a 6% grade for about 5 miles followed by a steeper grade to my house. The cooling system does not boil. I have a 22 with low radiator flat tube and no water pump. I also have 2 26-s same type radiator and no water pump. They all three run on 4 cylinders with spark and carburetor set properly. None of them boil. In the past, with Model A's I used tap water, and had a lot of problems with overheating. Our tap water is very hard. It lives spots on the chrome fixtures in the bathroom and kitchen after only using them for a few days between cleaning. It would clog the cooling systems of the cars very quickly.
Norm

[Art M]

I wonder what the difference is between the thermal expansion rate of the water and pure antifreeze. This could be a significant factor with a thermo cycling system. Maybe a waterpump is helpful.

[Scott_Conger]

Art

it is not about expansion; it is about density. I posted this on the other thread which will give you an indication that it should thermo-syphon just fine with 50:50 coolant:

50:50 ethylene glycol and water density at 0C: 1.0873 gm/cm^3
50:50 ethylene glycol and water density at 20C: 1.0824 gm/cm^3
after absorbing some heat, the hotter mixture of coolant mix is .0049 gm/cm^3 less dense, which would start the stratification eventually heading toward circulation (at a greater density differential)

straight water density at 0C but just liquid: 1.000 gm/cm^3
straight water density at 20C: 0.9982 gm/cm^3
after absorbing some heat, the hotter water is .0018 gm/cm^3 less dense, which would start the stratification eventually heading toward circulation (at a greater density differential).

And, as I posted in the other thread, if I could find values for operational temperatures, I would post them, but I suspect, as empirical evidence indicates, that coolant at the correct ratio, works just fine. The only downside is that the specific heat for coolant is slightly less than for water and for a given heat input, is approximately 20% less efficient (at it's ideal mix ratio) at removing heat than pure water, gallon for gallon of cooling capacity. For the added benefit of keeping my blocks from splitting at -20F, and near-perfect corrosion inhibition, I forgive it for being slightly less efficient.

[TRDxB2]

he Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litres (1,650 cu in) capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was later called Merlin following the company convention of naming its piston aero engines after birds of prey. After several modifications, the first production variants of the PV-12 were completed in 1936. The first operational aircraft to enter service using the Merlin were the Fairey Battle, Hawker Hurricane and Supermarine Spitfire. The Merlin remains most closely associated with the Spitfire and Hurricane, although the majority of the production run was for the four-engined Avro Lancaster heavy bomber. A series of rapidly-applied developments, brought about by wartime needs, markedly improved the engine's performance and durability. Starting at 1,000 hp for the first production models, most late war versions produced just under 1,800 hp, and the very latest version as used in the de Havilland Hornet over 2,000 hp.
https://en.wikipedia.org/wiki/Rolls-Royce_Merlin

[Steve Jelf]

Will straight water cool my T better than 50/50? Maybe. But I don't care whether it does or not. As long as 50/50 prevents rust and cools the engine sufficiently, it's better.

[It's Bill]

I wonder how many cooling problems are caused by badly adjusted carburetors? Hmmm, Bill

[Been Here Before]

I would like to thank those who gave information and advise on the use of 100% glycol for coolant. I will continue my use of 100% mixture as a coolant in the motor. From my review of the current and past comments on the operating of the motor, as long as the coolant /motor temperature does not exceed 230 degrees Fahrenheit and there is adequate oil splashing around the journals, there should not be a problem. My motor should not self destruct. Yes I know there are those who live where the temperatures drop below 9 degrees Fahrenheit, and that is a concern Again thanks.

[Charlie B in N.J.]

"You can lead a horse to water but you can't make him mix his anti freeze with it". Which, by the way, is probably stated on any container of 100% anti freeze. Mix with water that is.

[katy]

Here's a chart, courtesy of Detroit Diesel:
[image][/image]

[Scott_Conger]

George, I simply have to ask: since straight, pure, 100% coolant is an absolute terrible conductor of heat and was never intended to be used as a coolant by itself, why on earth would you do it? I mean, there is a reason you're using it. Perhaps I missed it, but I did not see where anyone advised a 100% ethylene glycol coolant in the responses, and if you received that suggestion privately, well, that was simply horrible advice.

100% pure coolant has a specific heat of .65, meaning 65% efficiency of the cooling capacity of water. Anyone wishing to keep their T around for a while longer will not tolerate the constant corrosive effects of pure water and settles on some compromise of heat removing capability for that of benefiting from corrosion inhibition, be that soluble oil in water or a 50:50 coolant.

100% coolant is not a compromise on heat removing capability; it is a complete abandonment of understanding of the science and is the adoption of a position that does not improve the car's operational ability, and in fact inhibits it with no gain or any benefits whatsoever.

I ran 100% coolant ONCE by accident. My car ran unbelievably hot (original brass round tube radiator). It took 1/2 of a summer to figure out what I had done. Replacing it with 50/50 mix tamed the car right back down and overheating has never recurred.

The great thing about this forum is that everyone is free to do as they please, even gluing their wheels onto axles if they wish, and neither I nor anyone else is the arbiter of what is "right". However, there is a thing called "science" which when combined with common sense, is usually beneficial to the person willing to apply both.