<VV> Electric cooling fan results

[Tony Underwood]

At 01:21 PM 7/29/2007, Sethracer at aol.com wrote:


>I also wondered whether another gas motor - small, maybe something 
>like a weed eater or chain
>saw, could power the fan at the optimum speed - or close enough. Now, that
>would attract some attention. Before beginning your runs, you walk 
>around to the
>rear and pull-start your cooling fan drive engine. Or, better yet, have a
>starter drive sticking up through the deck lid and use a wireless 
>impact wrench to
>start it. Cool! - Seth Emerson




By any chance have you taken a look under the decklid of Spike?

Supercharging by B&S...;)


Then again, with a small gas engine driving the cooling fan, it 
offers the option of tieing in the throttle to the gas engine driving 
the fan so it could be varied with engine rpm so as to keep the 
braaaat! racket to a minimum in the pits or lineup etc.

By the way, the trick here is to use a gas engine set up for powering 
larger RC airplanes, such as the 1/4 scale models which would use an 
engine pulling a 24" prop etc.    Those engines have some decent 
carbs that allow good variable throttle, and are capable of running 
WFO for long periods at well over 6000 rpm as well as idling fairly 
smoothly at ~1000 rpm depending on the prop.

They also have the advantage of a crank flange already configured to 
mount a prop, easy enough to bolt on an adaptor to mount a 'Vair 
cooling fan or whatever fan you would wish to use.    You *would* 
have to remount the carb so as to allow the engine to mount 
vertically rather than horizontally.

If nothing else, it would likely cost less than converting a Porsche 
type fan or trying to make something electric work.


tony..