I was wodering today about this scenario: A daily driven street car with the usual mods, driver decides to fit a big radiator to suit extended rev sessions. During normal city driving operating conditions could one of these super racing radiators cool the water too much; so that when the thermostat opens the coolant that circulates from the radiator is only, say 50° (or some temperature lower than would normally be achieved or desirable)? Surely this would not be good for the engine, contantly cycling to lower than design operating teperatures. Has anyone ever measured the outlet temperature of their coolant from the radiator? I remember recently a friend showing me, on their car equipped with one of these large radiators, that the difference in temperature across the radiator was easily noticable by touching the top at either end.
simple answer: NO That is the whole reason for the thermostat. Its not the low water temp to cause a concern, but say you blow a hose and put SUDDENLY cold water througgh it, that could pose an issue. Second of all, the primary cooling system is oil, its not just there as a lubricant. A scenarion where a "big radiator" could be harmful, is where no thermostat (or a broken one) is being run, preventling the engine from reaching WOT in due time, this is based on the theory that engines arent warmed up before they are driven in modern times. As a side note many engine builder/racers/manufacturers recommend gentle driving and not idling of an engine to reach WOT. m'kay
Yep...cause your engine isn't the only thing that needs to be warmed up...gearbox, diff, both use oils that are designed for best protection at operating temps.
