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With reassembly just a few weeks away, I'm looking into some details I haven't looked into for years - decades, even. It's been a while since I had a car in which the cooling system wasn't either a "sealed, forget about it" system or a "just keep adding to it all the time" system. :)

So: "anti-freeze." We don't freeze here - at most, we have ten or a dozen nights that dip into the high 20s. So I don't need freeze protection.

I do need corrosion protection, especially with a bimetal engine. And as we all know, I need all the cooling capability that can be crammed in - especially in 100-110 degree summer days, which we have plenty of.

I've done a fair amount of digging and as nearly as I can tell, anti-freeze doesn't do anything WRT cooling except raise the boiling point a little - like, to 220. Unless I'm missing something, most race vehicles not only don't use (ethylene glycol) coolant, but aren't allowed to for track safety reasons.

And, finally, I came across THIS piece of commentary. This guy is a Ph.D. with special interest in heat transfer and liquid heat characteristics, as well as a gearhead... and he says firmly that 100% water has the best heat-transfer capabilities.

So what are the arguments AGAINST running 100% distilled water with Water Wetter and a corrosion inhibitor instead of any standard anti-freeze mix? With a slightly higher pressure cap to increase the boiling point?
 

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I would expect you are safe in substituting antifreeze for something else. Actually, "water wetter" has corrosion inhibitors in it and they recommend straight water (I'd use distilled so I wouldn't worry about water hardness) for maximum temperature reduction.

You don't want to run just water, however. It's not called the universal solvent for nothing! Besides being extremely corrosive, it will boil unexpectedly and violently when it reaches boiling temps (slightly over 212° F depending on pressure). Not pretty.

Since you have a new system, have you considered waterless coolants, like Evans non-aqueous propylene glycol? They seem to be a good fit for your situation. ::
Daniel
 

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Short answer - none whatsoever. Be aware only that corrosion inhibitors have a fixed service life, and so must be periodically amended or replaced. But the same is true of antifreeze.

Go for it - ::
 

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This is a question often asked, and is certainly not as simple as may first meet the eye. This article from Grape Ape Racing is the best one I've run across. It pretty well addresses all of the pertinent facts surrounding your question, and does so in an easy to read style.

Just a word of caution in thinking you don't need any antifreeze at all for freeze protection. Once knew a guy who got in his car on a cold morning, started it up, and took off down the road. He figured the quicker he got moving, the quicker his car would warm up and hot air would be available from the heater. As he drove, the engine warmed up, alright. It got so hot that he had major meltdown and ruined his engine!!! Sure, he should've pulled over when it heated, but he didn't.

Why did the guy's engine burn up? One might think low on fluid, thermostat never opened, or ??? I mean, after all, it was in the mid 20's, so it shouldn't have heated up. What actually happened was, as he drove down the road, the fluid in the radiator froze solid before the thermostat opened. The road speed and fan action on that old 55 Ford simply froze the cores up almost immediately upon starting the engine because he had little (or no) freeze protection in it. This effectively prevented any fluid circulation in the system when the thermostat did open up after several minutes of running. Wouldn't want the same thing to happen to you. The last bottle of water wetter I used said to add 15% antifreeze with the product. Your call.
 

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Discussion Starter #5
The last bottle of water wetter I used said to add 15% antifreeze with the product. Your call.
That's not unreasonable. I'd have to look at the charts to see how much AF is needed for 20 degree protection.

That said, I'd be unlikely to start the car up and try to drive away on it on a very cold morning without being cautious. As I said, we have only a handful of nights that cold, with high 30s the usual minimum during winter, and probably 250 days of 40s and up. Way up. :p

But being aware of the limitations is quite useful.
 

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The Red Line folks also say that no antifreeze at all provides the best temperature reduction. The advice to add 15% antifreeze is a "just in case" measure.

I would also advise a closed system with a recovery tank.

7
 

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Hello!

I won't pretend to know all of the answers...but I also looked into this for my flathead Fords...known for their hot temperment. I work at a petrochem company in Houston, and our antifreeze gurus (with decades of experience) had some definite opinions. A couple of thoughts:

1) Theoretically, antifreeze is not needed for your car, it actually increase the boiling point a little over straight water. So, if your cooling system needs help...this will work, but only for a short time before other surprises will start.

2) Water, cast iron, heat and air make some very nasty byproducts, including acids, etc, which will corrode the heck out of your new engine, radiator, seals and water pump.

3) Antifreeze contains corrosion inhibitors, pH adjusters, water pump seal lubes, which prevents the damage from the above. Our gurus recommend it at about 25 to 50% or so in the cooling system.

4) Pure PG coolant is great...theoretically. It won't boil over until you're above 350 degrees. Unfortunately, motor oil will be breaking down, metal will be getting very weird...warping, and seizing...not good, for a new motor. I would use this only for competition engines, or for very old, tired engines with terminal cooling problems.

5) If I were going to do this, I would use some of the long-life DexCool antifreeze (I won't mention the brand)...or it's equivalent...it will last a long time, and provide max protection to the cooling system metals. It will keep your newly built engine cool, and in in good condition. The manufacturer recommends that it not be mixed with regular antifreeze (it will do no damage, but some of the long term properties will be lost), so now is the best time to do it. I would also use distilled water as the "make up" water in the radiator (no additional minerals). Most manufacturers recommend 5 year or 50,000 mile change interval. I change it about every 3 or 4 years...

6) As far as the "new stuff," most of it has been tried before, and works, upt to a point. But if your system is new, and in good condition, you should be able to do very well with the long-life antifreeze...cars have been using the EG-based stuff for decades...even high performance cars...and they lasted a long time with regular antifreeze changes.

7) The recommendation to add an overflow tank is a good idea...it keeps the air out of the cooling system, and contains it to only the overflow tank. Less oxidation of the antifreeze additive packages.

I'll get off the soapbox...but I've used our guru's advice on all of my old cars...and they've been running fine ever since.

Ray
 

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Antifreeze reduces the corrosive capabilities of straight water AND also raises the boiling point of the water.
 

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Discussion Starter #10
2) Water, cast iron, heat and air make some very nasty byproducts, including acids, etc, which will corrode the heck out of your new engine, radiator, seals and water pump.
An argument, I think, for changing coolant more often than is usually done - at least once a season and definitely once a year, mileage irrelevant for most of these cars. I plan to change coolant at least at the beginning of each hot season.

3) Antifreeze contains corrosion inhibitors, pH adjusters, water pump seal lubes, which prevents the damage from the above.
What I'm considering is an alternative mix of additives that have little or no freeze protection but add the corrosion inhibitors and anti-steam ("wetter") agents. The higher water percentage will give better cooling, but those protections are definitely needed. I'd rather add them straight, though, rather than depend on the antifreeze proportions to do it for me.

4) Pure PG coolant is great...theoretically. It won't boil over until you're above 350 degrees.
The issue with a high boiling point isn't for the whole system, but for pockets that can form around hot spots, exacerbating the hot spot problem. If the engine hits the boiling point of about 250 with a regular antifreeze mix, there are already going to be other problems. But hot spots can go way past the average temp of the coolant and form steam bubbles, which reduce local cooling. The higher the boiling point of the coolant, the lower the incidence and severity of these pockets.

7) The recommendation to add an overflow tank is a good idea...
I wouldn't try to run an engine without a coolant recovery tank any more. I was pleased to find something besides those awful plastic-bottle-in-a-cage things the auto partz places sell. :)

I *think* I'm looking at distilled water, Water Wetter, and 20% propylene glycol. PG because of the safety issues - I have kids and pets around. I might run 10% PG summer and 20-25% during the cold season, depending on how often I want to change out the coolant.
 

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Why change it more than you have to? That stuff is horrible for the environment and isnt going away/
 
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