Anti-Freeze - Water - Cooling

[bcomo]

Some thoughts on the ratio of Water to Anti-Freeze, and cooling.

1. Water by itself provides better cooling because it has a higher boiling point than Water mixed with Anti-Freeze.

2. Anti-Freeze is added to water because it lowers the freeze point of water, and it provides an anti-rust inhibitor. BUT, Anti-Freeze also lowers the boiling point of the water.

3. At 50-50 Water/Anti-Freeze the freeze point becomes 34 degrees below zero, as compared to 32 degrees above zero for water alone. BUT, this mixture will boil at about 20 degrees lower than water alone.

4. If you live in the North, and need the low freeze protection of -34, then use 50-50. Overheating of a healthy engine isn't usually a problem in the north, so the lower boiling point shouldn't be a problem.

5. If you live in the South, then low freeze protection isn't necessary since temps are rarely freezing. But, a higher boiling point of the coolant is what matters. In this case, using a ratio of 60-40 Water/Anti-Freeze will raise the boiling point of the mixture -- allowing the coolant to absorb more heat before boil-over.

[seven up]

Never heard of your 1. advice before.

[bcomo]

It seems that you are right. I was using figures from charts that had Water Wetter added to Water and added to 50-50 Water/Anti-Freeze.

Since all of what I said was based on those charts -- disregard what I said. Glad that you got me to re-read it.

[seven up]

Hey, Your thumb is working real good though ! That's good news !

[dgs]

There were some editorials on this in Car and Driver a few years ago. It is true that straight water cools better than a 50/50 mix of water and anti-freeze. This came from anti-freeze manufacturers in response to a question on how to make the editor's hobby cars usable in the August heat when they typically won't run cool. However, running straight water will result in corrosion and in a hurry.

I think you can buy the rust inhibitors alone and add it to the water, but I'm not 100% sure about that.

You might be able to find the editorials (there were 2 parts, I think) on Car and Driver's web site.

[Alexander]

I agree, running straight water is a mistake. I have flushed many a car running straight antifreeze, including a Squarebird. The amount of rust coming out in the flushing makes you wonder if there is any engine metal left.

Antifreeze raises the boiling point, that article is wrong.

[bcomo]

Since I started this thing:

Yes, you should not run straight water because of rust an freezing point is too low.

And, yes it appears that 50-50 does raise the boiling point.

Here is what I originally was going from, but didn't realize that they were talking about WITH the addition of Water Wetter. http://www.racerpartswholesale.com/redtech3.htm

This is another article written by a Heat Systems Engineer: (Does Water Wetter really work?)

http://e30m3performance.com/myths/more_myths1/Water_Wetter/water_wetter.htm

[dgs]

Found that C&D article here (It's part 2 of 2. Part 1 is here.). A snippit:

All the antifreezes I know have one side effect that's troubling for a few of our special cars. Ethylene glycol, which makes up 96 percent of what's in the bottle, has about half the heat-transfer capability of plain water. So when you mix antifreeze and water in the recommended 50-50 proportions, you give up a quarter of your system's cooling capacity. No problem for new cars; they're engineered with capacity to spare. But I remember British roadsters of the '50s and '60s that would boil on the streets of New York in the summer, and street rods are notorious for overheating. You could cure the cooling problems of those cars by circulating plain water through the system.
Most NASCAR racers do that. But corrosion sets in amazingly fast. Turcotte showed me a sample of coolant that had run 35 laps. It had flakes of red snow swirling through it—rust.

At the time of writing, there was no easy solution for gaining corrosion protection without the glycol that lowers the cooling capacity. It was written over 5 years ago, however, maybe there is now. There were 2 Zerex products recommended, Z-05 (with glycol, but superior corrosion resistance) and Racing Super Coolant (no glycol, just corrosion inhibitors). The number for Valvoline (makers of Zerex) is 800-TEAMVAL if you're interested.

[Guest]

Boiling Points W/antifreeze Is Higher

C2H6O2 is chemical make up of most anti freezes

pure water boiling pt 212F
50/50
C2H6O2/Water boiling pt 223F

70/30 boiling point 235F

[dgs]

I'm no chemist (or is it physicist?), but perhaps the boiling point and cooling capacity are two different things. Cooling capacity (I'm guessing) has more to do with thermal transfer than the boiling point.

Think aluminum vs. steel. Aluminum transfers heat much faster and is why it is used for heat sinks and the like. It sucks the heat out fast, but it will melt at lower temps than steel.