2GNT.com Forums - Viewing message - RE: *Sigh* Problem remains

Originally posted by BigBald

Reprint from an article I found: The next most common myth is: I have to slow the water down to help it cool. If this is the case; some is good more is better. Just stop the water. As silly as this sounds there people that suggest you do exactly that. Remember what you are cooling. You are not cooling the water you are cooling the engine. A running engine develops a lot of heat. The exhaust temperatures on well tuned race engine can be at 1300 degrees. On the other side of that exhaust port is a water jacket. If the water was to move too slow or be stopped, it would take no time at all for the heat to be transferred to the water. The best coolant and the best pressurized system will still have a boiling point below 300 degrees. Temperatures this high will mean that a steam pocket will develop and continue to grow until the heat source is removed or a large amount of coolant is brought to the area to soak up the heat and resultant steam pocket. This is the reason I tell anyone who drag races to not use a thermostat. If the water is stopped while you are at full throttle, these hot spots will cause detonation. Even though you can’t hear detonation on most race engines, your time slip will reflect it. If you find yourself saying “my car ran 3 to 4 off for no reason” this may be your answer. The higher the water flow the better for cooling. Remember a water pump’s job is to move the hot water out of the block to the radiator. The radiators job is to remove the heat from the water and pass it into the air stream. If you get a 15 degree drop across the radiator at 20 gallons per minute and a 10 degree drop at 50 gallons per minute you cooled more water at the higher flow. During a drag race, (short burst at full throttle) if the heat exchanger (radiator) can’t keep up, very little or no degrade would be noticed. If the tables are turned; the water pump can’t keep up, your ET and consistency will suffer greatly. The reason is, if the water temperature increased from 170 to 190 in 9 seconds, this would stay well within the tune up on the engine. If the water pump was not pumping enough water the metal around the combustion chamber may go up several hundred degrees.

Take it how you want it......

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-Tony <--- NOT asian.
'06 Wicked White EVO IX