Regarding this year's edition of the Great Electric Fan Dispute, Randall
Young writes:
> somewhere around 100mph sustained, the engine is putting out
> around 100 hp, which means about that much heat also has to be
> removed from the radiator. At 30 mph, we're talking under 10 hp,
> so less than 1/10 as much heat needs to be removed from the radiator.
At high vehicle speeds, the airflow through the radiator is pushing the
blades of the electric fan -- not the other way around. At that point, the
fan is making no contribution to cooling, whether it's pushing or pulling --
or even whether it's turned on.
Dave Massey wrote:
> Perhaps as a racer you can shed some light on the question of heat
> extraction at speed. Since you typical are on full throttle when you are
> not braking you are generating a maximum amount of heat on the track.
> Have there ever been any situations where the cooling systme could not
> keep up under these conditins yet cooled well enough at idle with the fan
> on?
The only time I turn on the (front-mounted) electric fan on my TR6 vintage
race car is while going to and from the grid, during pace and cool-down
laps, and for a few minutes after shutting the engine down. Once the race
starts, I turn the fan off. With a modest 10.5/1 compression ratio, a 6000
rpm rev limit and an average lap speed of 80mph, the car did not overheat
using the stock TR radiator.
Jim Hill
Madison WI
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