Pully vs. Electric fan

Here is another interesting thread about mechanical fans vs. electric fans: http://mmb.maverick.to/showthread.php?t=19645&highlight=electric+fan

 

I don't know about 35 ponies, but dad used to put an oversized belt on his race car so that it would never get tight no matter how much you ran out the tension bolt. It passed tech that way and was too loose to spin the alternator.

 

Do you have a fan controller on it or do you switch it on/off manually?
Also, I have mine mounted as a pusher fan in front of the radiator. I don't know what size mine is by memory either, but you might have room for a bigger fan as a pusher. I don't have a condenser mounted though.

 

The only way to know for sure that the fan is running is to wire the light in series with the fan. Since an LED doesn't need many volts, it might work to put the LED in series in the ground wire, like this. Would that work?

 

No, that won't work. The LED can not handle the current draw of the fan. LEDs are generally rated at less than 2 VDC and 5-20 mA. The LED should go from the fan's + wire to ground with the appropiate dropping resistor. When you buy a 12 V LED it already has the correct resistor imbedded to drop the voltage to around 2 volts.

 

i was thinking about how to tell if your fan is working or not. the simple answer that i could come up with is to put a amp meter gage inline with the power wire to the fan. that way you can tell when the fan is on or not. if the motor goes bad or the fan blades are kept from spining for some reason the amp reading will be different than the normal operation for the fan. I think im going to do that to mine. I run a summit alum rad and a ford escort elec fan, with a mizier elec water pump. It will heat up on a hot day at a stop light. Im looking at changing the motor in the fan to one out of the lincon mark 8 fan. those fans are awsome. they flow something around 3000 cfm. there are lots of info on them on the corral.net website. the lincon fan is to big to fit into the mav. the escort fan fits like a dream. if the motor can not be changed then i will add a pusher fan. Also note my motor is around 11 to 1 compression and generates a good amount of heat to disapate.

 

ok just checked the lincon fan, its motor is the same dementions, so i figure its the same motor, just a much biger fan blade is used. so i guess im going to add a pusher fan.

 

The Lincoln Mark VIII fan is the best power puller, however, it has it's draw backs...

It's an 18" fan. Estimates of CFM are between 4300-5500. Draws 42amps on HIGH speed--it is a 2-speed fan. 1100 rpm in slow, 1850 rpm in fast.

42 amps on high is too much if you're running a stock alternator.

a good median would be better... like a 3000 cfm with 18 amp draw.

 

i've run electric fans on everything for the past 6 years. my last car had a flex-a-lite black magic fan...that thing would pull a cat through the radiator. ii dont use thermo switches though. i always keep an eye on my gauges and just manually turn my fan on whenever im in traffic and off when im on the open road. whats really nice about them is when you're doin autocross/drags/some sort of racing you can lay a bag of ice in your lower valance while your staging and pull in really cold air. sounds kinda dumb but it helped keep everythign nice n cool when im in really hot pits with the car ahead of me exhaust shooting at my rad.

 

Easiest thing to do is watch the temp gauge. If it overheats your fan ain't working! I have mine set to come on at 195*. If it would get over 200* somethings wrong. I have a PermaKool that's rated at 2950 cfm. Problem is you can't compare fans by their cfm rating, there is no industry standard as to what type of load the fan has to overcome to simulate a radiator.

 

Mine is just on a toggle switch that lights up when you turn the fan on. The toggle switch gets power from the radio circuit, that way the fan will turn off when I turn the car off regardless of if the switch is on or off. My '73 I plan to run it on a controller, but I am still going to have a little LED or something in the car to tell me when the fan is on and off.

 

the question is...how are you going to wire it???

......

 

i don't know of any new cars/trucks that have a ...warning lite...for the fan...(temp idjet' light) maybe
i have seen/heard of a lot of motors...overheating...because the ...fan stopped.

... ...

 

Hot Rod mag did a test way back when, and a fan with a thermostatic clutch actually made more power than no fan at all, due to the ballance effect on the water pump bearings
centrifugal clutch fans drew the most horsepower at @15hp
also remember that even the smallest front driver has a 120 amp alternator not a 35 to 50 amp and all have built in regulators or are computer controlled
you are putting a huge load on the elect system by going electric, most of the fan relays are 30 to 40 amps
ford used really small batt cables and wiring on our cars, but that was ok cause biggest draw was the headlamps