by RedMist » Sat Feb 05, 2005 3:34 pm
In the end it's all about combustion chamber temperature. Your attempting to keep the combustion chamber hot enough to get a complete burn, but not hot enough to create pre-ignition.
Using water temperature to approximate combustion chamber temp isn't the best methodology. The water galleries are different in each engine, flow rates are also different which effects the amount of heat you can drag from the combustion chamber.
No offence but from what I know of Dave Visard he worked on BMC and old pushrod 8's in the 70's where combustion temperature would have needed to be lower as combustion chambers were more prone to detonation and the combustion chamber wasn't cooled as efficiently. Using 70 degrees across the board isn't a fair statement. Bruce, is the quote in regards to a specific engine? In regards to Dave stating that the oil will contaminate quicker, I think that would happen even with todays engines. I think he's referring to the evaporation point of fuel.
Atmosports has a better approximation. Some engines produce more engine when run hotter OR colder. It'll depend on any headwork, plugs, fuel air, CR, piston shape, CC shape, CC cooling efficiency and a tonne of other factors. Needless to say I'll not be putting a TRD thermostat in my engine.
The answer is Helmholtz!
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