Waterwetter

[ELP_JC]

A negative effect not mentioned is the water pump would last a lot less due to lack of lubrication.

JC

 

[jestal]

jestal, I'm not sure where your number comes from. The only chart I could google up quickly gave me this:
The boiling point of water at 30 psia (the 15 psi operating point of most cooling systems is psig and represents pressure above atmospheric pressure) is about 250 degrees. The motorcycle cooling systems I know of are all designed to maintain about 220-240 maximum.

For comparison, a 50/50 mix of propylene glycol and water has a boiling point at 1 atmosphere of 222 F. Ethylene glycol gives you a couple more degrees (and toxicity) at 225 F. So the typical 50/50 mix gets you about a 10-13 deg increase over pure water. Doesn't seem like much but given the narrow margin for error between normal operating temps and the boiling point, its good insurance.

I am not sure which number you are talking about that we are in disagreement.

A cooling system at 15 PSI with 50/50 EG/distilled water will not boil until 265 F or 128 C and there will no apparent signs of "oveheating." As long as the system is pressurized and has the 50/50 mix there is little to no risk of any engine damage even if the coolant temp does get to 265 F. There is a fairly large margin between normal operating temps of 220-240 and 265.

 

[C&C]

Jestal's numbers can be readily viewable on the back of an antifreeze container. A 50/50 mix yields boil over protection to 265 degrees F. at 15 psi, while a 70/30 mix will yield boil protection to 276 degrees F. at 15 psi. This, per the fact sheet on the back of a Prestone container. The ratio is antifreeze/water.

 

[weekend rider]

So two things, the higher the content of EG to water the higher the boiling temp.

Water boils at 212 F at sea level zero pressure

All that stuff wet water. redline, and what ever else is "junk" and takes and waste your money.

After all the info, it boils down to mixture and what your cooling system operating pressure is designed for.

Simple pressure up tempurature up sounds like a direct acting system to me.