Kaw Rider posted a great write-up called Coolant Replacement Tips, I think. It was a long informative thread, and he even summarized it after discussing the factors of the cooling system and the characteristics of the different coolants.
the bottom line was dionized water (distilled is good), water wetter, and a minimum of anti-freeze. Water removes heat from the cylinder the best. Water wetter reduces the water's surface tension to help remove more heat which reduces operating temps. The anti-freeze will raise freeze point and boiling point. I think the idea is to run what your engine needs. He posted that a modified motor has a higher operating temp, so not every motor has the same requirements. It was also good to know that there are products out there that are bad for seals, gaskets and aluminum.
Engine Ice requires a lower pressure radiator cap, according to Kaw rider, also. I was running anti-freeze full strength, which would never boil over, but also would not remove heat from the engine very well. So even though , I'm not apparently overheating because of no boil over, but in reality, cutting off the life span of the motor. Its very critical to get the engine to its optimal running temp and to stay there. I have heard that there is power to be gained there, but I am sure there is power to be lost there if not done right.
