Originally Posted By: racin4ds
Originally Posted By: Shannow
Water wetter makes the parts inside the engine hotter rather than cooler.
When those products advertise reducing the coolant temperature, they are actually removing LESS heat from the engine, and causing metal temperatures to rise.
Shannow I just don't think this is correct. These products INCREASE the heat transfer properties of water and have been tested and shown to work, although marginally.
From Redline:
WaterWetter® reduces the surface tension of
water by a factor of two, which means that much
smaller vapor bubbles will be formed. Vapor bubbles
on the metal surface create an insulating layer which
impedes heat transfer. Releasing these vapor bubbles
from the metal surface can improve the heat
transfer properties in this localized boiling region by
as much as 15%
If they form smaller bubbles then there would be less free space between bubbles and less of the more efficient heat transfer area (liquid to metal) available.
If it requires less energy to form and release those vapor bubbles because of the "reduced surface tension", then the coolant would absorb less energy before boiling, thereby leaving unabsorbed heat behind.
You want a coolant to take as much energy as possible to convert from a liquid to a gas, that's the deep part of the heat sink. You do not want to make it any easier for the liquid to vaporize and boil.
These products help machine cooling in one way compared to traditional antifreeze products, by less dilution the best possible cooling medium we've got (plain water).