Another "old mechanic's tale" (That's an old wives' tale about fixing cars) is that an engine is "overheating" when the coolant isn't boiling. The clearances built into the rotating assembly, valve guides, and other oil-lubricated parts determines the point where an engine is running "too hot". If you want a higher operating temp for whatever reason, install the appropriate thermostat to keep the coolant at the minimum temp you want, clearance the moving parts to be happy at that temp, use a lube oil that works at your target temp, and build a cooling system that will transfer enough heat to keep the whole works at your pre-selected temperature. Use enough cooling system pressure to keep the coolant from boiling. Every pound of pressure on a 50/50 mix of water and antifreeze raises the boiling point at sea level by 3 degrees F. A 15 lb. cap keeps the coolant from boiling below 257 degrees at Daytona Beach- - - - -the "boil over" temp is a little lower at the top of Sonora pass at 10K+ feet elevation.
Like a lot of other things stovebolt-related, making very generalized statements about engine cooling is rarely doing anything more than stirring up a bunch of hot air!
Jerry
