Getting hot on the highway with the AC on.

bob mCcarty said
I tried that on a pretty hot 406 sbc , it didnt work , built restrictors to slow it down , eventually wound up w/ a 5/8 hole in the restrictor that worked great!
Proving to me , that water can be circulated too fast !! ( a mech. friend told me that I would wind up w/ a 5/8'' hole before I tried all of them !
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No that just means that there wasn't enough pressure in the block which lead to water boiling in hot spots and creating steam bubbles in the coolant, which made it more inefficient. You can't go too fast through the radiator it's been explained by me and other people on the thread many times.
Example:
Let's say you have water molecules go once every 10 seconds(just a random number not an actual time) through the entire cooling system, it will spend more time in the engine which means that it will slightly boil and create steam bubbles. now make it complete the cycle in 5 seconds, it will pass through the radiator 2 times in that amount of time so it will still shed a lot of heat, but it also won't have gas bubbles inside of it due to boiling.
You can't physically spin a water pump fast enough for it to be an issue with it.
You did a test with uncontrolled factors and assumed something without thinking there are other elements at place. I had a friend that changed his water pump for a flowkooler one and a smaller pulley, then he had issues with overheating. His water hose was collapsing at high rpms. But until i pointed that out he was sure that the "too fast through the radiator" BS thing was right
yellow rose did a much better write up than i did about it and i recommend reading it. There are also ton of cooling companies with good articles on it
Stewart Components
Here is one