It all started when we were kids. We are the ones who colored OUTSIDE the lines.

 

 

There was something very very wrong with that vehicle other than the antifreeze mix!!!!!!!!

 

Maybe, maybe not ...

http://www.gi.alaska.edu/ScienceForum/ASF6/680.html

 

Man, you're wasting your time, he already knows everything.

 

I think DTS419 has it figured out.

Mountaineer, You might want to add at least a little water to your antifreeze. Temp's article states that pure antifreeze will freeze at a few degrees below 0.

Antifreeze at 35% freezes at the same temp as pure antifreeze.=http://www.acustrip.com/specs/fp.pdf

 

pure antifreeze is not as efficient as 50/50 mix in transferring heat from the engine/cooling system.

30% antifreeze and 70%water is the best for heat transfer.

50/50 is the best compromise for freezing/boilover protection vs heat transfer

 

Yeah, and if your thermostat is rated for 195, that's the temperature your engine will run at regardless.

People need to understand one simple thing. If you use some magic formulation whose heat transfer properties are so amazing that they allow 10 degrees cooler, guess what's going to happen as soon as your coolant temp dips below 195. Yep, that's right- the thermostat is going to close until the temperature comes back up enough to open it.

Using the wrong mix could cause overheating. But using your home chemistry kit to brew a 68-32 ratio or whatever you read from some sourceless website is not going to caus your engine to run any cooler than the stat allows it. Bottom line: Use 50/50 since that's the design ratio for the best compromise for corrosion/boiling/freezing protection.

 

http://en.wikipedia.org/wiki/Engine_cooling

Even if the thermostat opens at 195 The coolant is flowing around HOT engine components. Does the antifreeze reduce the amount of bubbles that that form when flowing around the engine surfaces. If it bubbles too much you may get air pockets inside the engine which will create "hot spots" in certain parts of the engine.

Quote:

"Liquid-cooling is thus a good solution to a difficult problem, but sometimes it is even difficult to move enough liquid coolant to keep a part cool. When liquid coolant gets to an engine hot spot, it may boil, expand to a gas, and momentarily stop the flow of coolant over the hot spot -- which then becomes even hotter. When more coolant reaches the hot spot, it simply boils.

The gas bubbles may disappear again as they mix with newly circulated coolant, and the hot spots may be damaged by localized boiling even though the radiator contents are not unusually hot. Indeed, the engine temperature sensor may indicate the engine is running cool overall, even though one part is dangerously overheated."

So the question of the day is "Does antifreeze reduce the likelyhood of engine hotspots?".

 

Actually, based on thermal conductivity alone, 100% water is the best for heat transfer. Liquid sodium is even better. However, 100% water, as we've well-established, is bad for freezing, and bad for corrosion protection, not to mention its lack of lubricity for the water pump bushing.

Liquid sodium, of course, causes nuclear reactors in Monroe, MI to go boom (sort of).... that, and sodium doesn't play well with water either!


But I digress...


-Joe

 

The problem, as has already been explained numerous times, isn't the temperature at which the thermostat opens, or the temperature at which the engine was designed to run. The issue is the temperature difference or temperature gradient between the head and the coolant.

I'm making these numbers up, so this is a very simplified explanation, but this is the difference:

50/50 mix of coolant.
Assume the temp of the coolant is 160 degrees when it's entering the engine. The temp of the casting may be as high as (say) 240. It's the temperature gradient of 75 degrees that causes the heat to flow from the engine (hot) to the coolant (cold).

Say 100% antifreeze has about half the thermal conductivity of a 50/50 mix. Now, your inlet temp is the same and your outlet temp is the same thanks to the radiator and the thermostat. It will take twice as much of a heat gradient between the casting and the coolant to raise that temp to 195, so now, instead of the casting running at 240, it's running at 285 because the coolant can't absorb as much heat as fast.

So, yes, the coolant temperature will remain the same 195 degrees, but the temperature gradient between the heat source and the coolant will be greater, which means that the casting temp must be higher.

Does that make sense?

Thermodynamically speaking, straight coolant is bad by itself. Ethylene Glycol is not a good conductor of heat.

-Joe

 

minimum 50% water, 50% antifreeze- down to -34 degrees F, up to 265 degrees F

Maximum 30% water, 70% angifreeze- down to -84 degrees F, up to 276 degrees F.

All asuming use of a 15lb pressure cap in good condition.....

Right off the back of a Prestone Bottle

Don't forget that Ethylene Glycol provides a very important function in addition to corrosion protection, anit-freeze and anti-boil..... LUBRICATION. Yes, Ethylene Glycol is a lubricant for your MECHANICAL water pump. Do what the manual calls for... if it's 50/50, put in 50/50... temp and boil protection aside, you're thining out the very lubricant for your water pump.

 

Yes, that makes sense.


Quote:

"Water has twice the heat transfer capability when compared to 50% glycol antifreeze/coolant in water. Most passenger automobiles have a cooling system designed to reject sufficient heat under normal operating conditions using a 50/50 glycol solution in water. However, in racing applications, the use of water and Water Wetter will enable the use of smaller radiator systems, which means less frontal drag, and it will also reduce cylinder head temperatures, even when compared to water alone, which means more spark advance may be used to improve engine torque.".

But the key sentence here is:

"Most passenger automobiles have a cooling system designed to reject sufficient heat under normal operating conditions using a 50/50 glycol solution in water."

and the key words are "designed" and "Normal operating conditions".



http://www.racerpartswholesale.com/redtech3.htm

 

For the record, and for all trucks built for the 97 model year on up, the whole argument is moot anyways. Even if the engine temp gets too high, we have a fail-safe cooling system. Not only can you run with straight antifreeze, you can run with NO antifreeze, as in no coolant AT ALL! The engines are all equipped with fail-safe cooling, and in the event of an overheating condition (due to the wrong mix, lack of coolant, ot stuck thermostat) the engine will go into a reduced-power limp-home mode. Essentially the engine alternately fires four cylinders at a time, reducing the power and using the intake air to cool the engine. Sure, it's can't be good to run like that continuously, but you're not going to hurt the engine by doing so.

-Joe

 

Let's have Mattineer run 4K miles with his truck doing this, and then see what the results are.