Clutch fan operation
I have an issue with the clutch fan kicking in. I was under the impression that once the temps started to get around 195-200 degrees the clutch fan would kick in. With mine, it starts to kick in at ju...
Forum Discussion
Brian,
When setting up a cooling system there are a few basic rules. First, obviously, is a good radiator. Second is a thermostat that opens before the fan kicks on. When setting up cooling systems for my HP/Hot Rod customers I would always specify a fan switch, most guys ran electric fan(s), a minimum of 10 degrees hotter than the thermostat. You always want the thermostat open prior to an electric fan engaging. If the fan were to come on at 180 but the thermostat was a 190/195 the thermo would be late to open because the heat would be drawn out of the upper rad hose by the fan keeping the radiator to cold. In the case of a fan clutch you can have a fan clutch that engages below the thermostat because the radiator which it reads off of will remain cooler than its engagement point until the therm opens. This is the reason a fan clutch is actually better to use than electric fans when designing your cooling system. Electric fans are a compromise made because of space limitations. Having a fan clutch that comes on slightly before the thermostat opens, say 180 to a 185/195 therm, is good because it will still free wheel while the thermostat is closed but will engage almost immediately when the therm opens and the radiator starts to dissipate heat. I am trying to figure out why you are chasing this ghost but if you want to increase the temp your engine is running at, like your original post indicates, install a hotter thermostat and your problem is solved.
Randy
When setting up a cooling system there are a few basic rules. First, obviously, is a good radiator. Second is a thermostat that opens before the fan kicks on. When setting up cooling systems for my HP/Hot Rod customers I would always specify a fan switch, most guys ran electric fan(s), a minimum of 10 degrees hotter than the thermostat. You always want the thermostat open prior to an electric fan engaging. If the fan were to come on at 180 but the thermostat was a 190/195 the thermo would be late to open because the heat would be drawn out of the upper rad hose by the fan keeping the radiator to cold. In the case of a fan clutch you can have a fan clutch that engages below the thermostat because the radiator which it reads off of will remain cooler than its engagement point until the therm opens. This is the reason a fan clutch is actually better to use than electric fans when designing your cooling system. Electric fans are a compromise made because of space limitations. Having a fan clutch that comes on slightly before the thermostat opens, say 180 to a 185/195 therm, is good because it will still free wheel while the thermostat is closed but will engage almost immediately when the therm opens and the radiator starts to dissipate heat. I am trying to figure out why you are chasing this ghost but if you want to increase the temp your engine is running at, like your original post indicates, install a hotter thermostat and your problem is solved.
Randy
