Cooling Fan
 

Any recommendations on installing an electric fan to help with overheating on 1940 flathead. Would a fan help and if so what should I use?

Re: Cooling Fan
 

Forty, as others will suggest here, the first thing to do is to figure out the source of your '40's overheating problem....cooling system clogging, water pump failure, timing off, etc.

That said, an electric fan is a great addition, particularly if you're in summer parades or if you live in a place as I do where summer temps are in the three digit zone!!

I've always installed a "pusher" fan in front of my radiators controlled by a toggle switch under the dash. All my flatheads have been the original 6 volts, and the available fans have worked very well for me.

Hope this helps!!

Re: Cooling Fan
 

Another thought to add:
The fan only comes into use at slow speed, in slow traffic. If you are running hot at cruise speed, when plenty of air is being forced thru the radiator, then problem is elsewhere, additional fan will not help.

Re: Cooling Fan
 

Basic rule is, if you overheat at slow speeds there is not enough air going through the rad. If you overheat at moderate/higher speeds there is not enough coolant flow caused by restrictions in the rad, water pump, or the block itself..

Re: Cooling Fan
 

Even if you "crutch" it with an electric fan, and it is still 6 volt the 6 volt generator won't keep up.