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coolant additive

Started by phildeville@cox.net, August 30, 2019, 06:13:55 PM

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phildeville@cox.net

Anybody use "Quick Cool" by Granatize Products? I had surprisingly good results in my '67 DVC.
Phil Terry  CLC# 15270

papas52cad

I used purple ice, lowered temp by 10 degrees
1952 Fleetwood

cadillacmike68

Won't the thermostat just adjust to the coolant temp?

Unless I'm wrong, the thermo doesn't care what additive(s), and it will open / close to keep a constant temp.

That is, unless you are a high heat condition such as stopped in heavy traffic without sufficient airflow over the radiator in which case these additives will only slow down the eventual temperature creep until you start moving again. That's been my experience.
Regards,
"Cadillac" Mike

TJ Hopland

I suspect the additives in question are supposed to increase the heat transfer efficiency off the coolant.   I have a friend that has been in the heat exchange field for years and he says there is actually some science behind that idea. 

Pure distilled water on its own isn't especially good.  Its actually what is considered the impurities that help the heat transfer.  My friend says really 'hard' water is actually the best non exotic fluid for heat transfer but in most cases the hardness would end up causing so much corrosion the corrosion would start to inhibit the transfer.   

Most antifreeze formulas have things that help the transfer as well as anti corrosion so they kinda create a balance between efficiency and corrosion.  The special additives are supposedly just better than the stuff that already comes in your typical antifreeze formula.               
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

"Cadillac Kid" Greg Surfas 15364

An interesting topic. Glycol is about 10% less efficient in its heat transfer coefficient primarily because it is a better “wetting” agent and more readily makes a better contact with the surfaces it flows along. Glycol based coolants serve several purposes, all of which add up to more than equaling the benefit of the slightly higher heat transfer coefficient of water.
What some of these coolant “enhancements” do is to slightly increase the wetting ability of the coolant in the system. That does increase the efficiency of the cooling system.
That said, the cooling system including water jacket surface, water pump, thermostat range, radiator and radiator fan were designed to adequately transfer heat and maintain the desired temperature. In some older vehicles the thermostat is the controlling factor but is motors like the 472/500, the thermostat is designed to maintain a minimum temperature (195 degrees)while the rest of the system is designed to maintain the desired engine operating temperature (typically 205-220 degrees).
Modern engines are designed to run hot for increased thermal efficiency. More of the energy of the burning gasoline goes into power instead of heating the engine.
Long winded way to say unless there is something defective in the cooling system, running the prescribed glycol mix and thermostat will result in a longer running more efficient motor.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

fishnjim

Several eng'g points:
auto "thermostat" is a temperature responding valve, made to open at the "set" temperature to 100%.   It'll start opening before (onset) since it's mechanical.   They do NOT maintain a constant temperature like a house thermostat.   They can only close again after cooling, once opened.   Merely starts the coolant flowing to the radiator.   It also functions to allow the engine to warm to operating temperature.   Without a stat, it may not warm enough if cold out.   A lot of people believe that a lower stat will help overheating, but can hurt, because it won't get rid of enough heat in the early phases.    Q(energy tranferred) = U A DeltaT.   U is the heat transfer coefficient, A is the area for heat transfer.   The differential temperature, delta T, is part of the driving force so the smaller the difference the less heat remove, lower stat, less delta T.   Since A is fixed and U is controlled by the components, that's the only one that's left to operate.
That's why a car can "overheat" when it's too hot outside, the ambient raises so the approach temperature lessens.   The coolant system temperature can only go as high as the radiator pressure.   The pressure prevents boiling, which reduces heat transfer.   {Overheat to boiling is what causes it to spew out the cap.   So you never want to open the cap when it's hot.   Sudden release of pressure can induce boiling when your hands/face are in there.   Let it cool off, then put a rag over cap, close the hood down before turning the cap.   Caps have a stop to prevent it flying off.  If it comes out, step away.   Once it's OK, open fully.}
Glycol has less heat capacity than water and what makes it less effective as a coolant.   But needed for freeze protection - depresses freeze point.   
It's a lot more complicated than these points but I don't want to causes more confusion than is already out there.   Most cars are cooling capacity restricted by the air side of the radiator, not the liquid side in the engine.   Why you need to have a fan and better when car is moving.   Once they get old and gunked up, it's different.   A and U are affected.
So just because something is colder or hotter coolant temperature isn't necessarily a good thing because dynamics (time related) are at play.   I don't see any harm with +-10 degrees.   That's well within the operating range.   Then it's just a question of economics, is it worth it?