electric fan

[IaTR6]

With not enough to do, I began thinking about the electric fan on my TR6 with Ford V8. It is always running when I pull into the garage, and
I began thinking maybe when cruising down the road I don't need it running. So, to begin, I connected a light to the control, and planned to verify the running, whether it ever shut off, whether I could even tell and so on. Then, my mind wandered to the power consumption.
The fan draws 17 amp at 12V, which is a measly 204 watts, or ~.27 hp. I read constantly about the horsepower loss with an engine driven fan,
and can't reconcile this with my electric fan.
I suppose the engine driven fan has some additional loss from the belt, but even so, it doesn't seem to be the large loss I was expecting. A long
story short, is it even worth concerning myself with the fan running all the time? (I'll probably do my testing just because)
Dennis

[MGBV8]

Any particular reason you do not use an adjustable thermostat?

[IaTR6]

Sorry Carl, I left out the important info. I have an adjustable temperature control.
What I've done is make myself look silly for not spending the time to accurately adjust it.
I wasn't concerned too much since my temp never exceeded 200 degrees. What
I was thinking mostly, is it really all that important that the fan shuts off when
airflow through the radiator is sufficient for cooling?
Dennis

[IaTR6]

As an update: I have adjusted my fan temperature control to come on ~205 degrees, and it shuts off ~195 degrees.
Using an old instrument light socket and bulb as a visual indicator, I find the fan will run after sitting a little
while at a stoplight, and then goes off after a mile or so at 2000 rpm and 40 mph.
I didn't use a voltmeter to test, but if the fan is spinning and generates any voltage when it is freewheeling, it doesn't light the bulb.
So, back to the original question: does having the fan turn off at speed matter? I don't know, and now don't
care at all.
Now on to the next project: stop blowing the fuse to the ignition switch. Co-pilot not amused when helping push the car out of traffic
or towing me home with a strap. Went for a drive alone, and used 7 fuses to get home. Suspect EDIS unit. I doesn't even have LUCAS on it!
Dennis

[DiDueColpi]

Having the fan running at speed can be an issue Dennis.
Electric fans appear to be pretty powerful and generally they are, but their air speed is not as high as you would think.
They can actually become a hinderance to airflow at highway speeds if they are running.
OEMs generally program the fan off at higher speeds. Prior to that they would use vent flaps to allow air flow around the fan at higher speeds.
Ran into this very problem with the Suzuki race cars back in the day. They would overheat at speed unless we turned the fans off.
Put a speed sensor in and the problem went away.
Live like you mean it.
Fred

[IaTR6]

Thanks Fred, I'm sure my fan isn't running when I'm running on the highway. My bulb test leads me to believe that.
As an aside, the fuse I spoke of earlier, that kept blowing, feeds the EDIS and the switched source to my Megasquirt.
Fortunately, neither was the issue, but a poorly wrapped splice done by the same incompetent shade-tree mechanic that did all the other work!
I'm glad I never paid him.
Dennis