yamaholic22
Active member
Ok this is starting to make very little sense. No matter what way you put it water has a thermal conductivity than ethylene glycol, a higher specific heat (which is important even if reduced effect due to the rpm of the engine, it still has the ability to carry MORE heat away from the source), and the higher thermal conductivity transports that heat to the exchangers MORE QUICKLY than ethylene glycol. Ethylene glycol is used to lower the freezing point, raise the boiling point, and to reduce the corrosive effects of water in an engine. It is NOT USED to be a BETTER COOLANT. Even the thermal conductivity of 50/50 is MUCH lower than that of pure water. The thermal conductivity constant of pure water is 0.60, for 50% water/50% ethylene glycol it is 0.41, and for pure ethylene glycol it is a measly 0.25. Now it is fairly difficult to accurately create and measure the effects of surface tension inside a running engine, but in theory yes the water will have more bubbles formed at the hot spots (along the cylinders and head) than ethylene will due to the lower boiling point of water. The alcohol ethylene glycol raises the boiling point, which reduces the chances of small scale boiling at the hot spots that would cause gas bubbles to form. That being said, water still has MUCH more ability to carry away heat from the engine as long as you are pumping the coolant through fast enough that the cylinder walls the coolant touches do not get above the boiling point of the liquid at the given pressure of the system. That is why cooling systems are pressurized, to raise the boiling point further.