Electric fan questions

[stovens]

I need to put in a pusher electric fan on my truck. The engine is a mild build 460 and the radiator has a built in transmission cooler. The radiator is also a big sucker, all aluminum. It can fit up to a 19" inch fan in front.
My questions are 1) Is there a certain cfm I should get? The radiator shop guy said anything should work and no shroud was needed, but I'd rather get advice from you guys. Since it's a pusher it makes sense not to cover the rest of the area around the fan with a shroud, but the cfm's vary considerably on what I find in the catalogues.
Also 2) I know I've asked this before, but is Summit's brand good? Or should I dig deep and go for something like spal?
Lastly, 3) what about the relays to switch it on and off at certain temp ranges? Thanks Steve.

[jpelli]

Nothing works better than a puller with shroud. But if you need a pusher, I would go with the spal fan, and yes you need a relay.

[techinspector1]

I would only use a pusher on a stationary unit. I've read too many poor results with pushers on vehicles.

Nothing beats an engine-driven, 18" OEM 7-blade steel fan with a full shroud.

[MRJB1929]

Hi Steve,
Relays take the current away from the switch making the switch last longer. My suggestion would be to get an adjustable thermostatic switch where you can put the probe in a water jacket (on the water pump is a great spot), then from the adjustable switch to the relay and from the relay to the fan.

Pusher fans need to have a lot more CFM's to do the same cooling capacity as a puller fan. So if you are going to put a fan in there, it might as well be the biggest one you can get. Otherwise, why do it if it is only going to marginally help. Fan Shrouds work the best on Puller fans where it forces the air to be sucked through the radiator and not from the sides of the fan.

No help on the Summit fans. My friends and I tend to do somethings only once and fans are something we only do once. So it's SPAL for us.

[jerry clayton]

Get a Lincoln Mk8 fan--available on Ebay less than $100 and pull 5000cfm

[35chevy]

I used a 16" spal pusher on a Ford Ranger. The truck had a EFI 5.0 with a/c and the radiator was factory for a 4.0 v6. I had no cooling issues. I used a wiring kit with a relay and thermal sensor also from Spal. I called spal for a recommendation the fan and they were very helpful. I've used the wiring kits from painless wiring also and they work well too. The spal fan I had was very loud though...sounded like a shop vac, but cooled great. Definately use a puller if you can though.

[35chevy]

Get a Lincoln Mk8 fan--available on Ebay less than $100 and pull 5000cfm

Excellent fan

[stovens]

Thanks guys. It has to be a pusher, because there is less than an inch between the pully bolts on the water pump, and the back side of the radiator. It can be a big pusher though. I've heard several people now recogmend spal. I'll give them a call and see what they have to say. Steve.

[stovens]

Talked with Spal today. These guys are very helpfull! The tech guy said with my radiator dimentions the way to go would be two 12" inch high performance paddle blade fans with the 165 off 185 on sensor and relay. This would put out 3200 cfm. I asked if having one 16" fan would be better and he said no! He said I'd get my CFM's with the two 12" fans. Glad I called them! Gonna cost a bit!

[53 Willys]

Listen to spal
Area of 2 12"fans = (6x6 x 3.141) x 2 = 226.15
Area of a 16" fan= (8x8 x3.141) x 1= 201

[Blow by]

I would have to endorse Spal once again,I am in the situation of many that have very little room but am able to use a puller and have been very impressed with my spal.If I didn't have it there is no way that I would be able to cruise in a lot of the traffic that I have been caught in.

[jerry clayton]

couldn't a pusher fan actually generate current when driving at high speeds??????

If it only draws 10 amps, it isn't big enough for a heater fan

[34_40]

couldn't a pusher fan actually generate current when driving at high speeds??????

If it only draws 10 amps, it isn't big enough for a heater fan

I think any motor can become a generator if it's the right type.
And that's what I was thinking - my heater draws at least 10 amps.

[marks914]

The problem with a pusher is you are blocking the area that is behind the motor on the fan. Without a shroud, you are also missing out on some square inches for cooling.

Mark

[stinger99]

I just p/u a Taurus/Mk8 Fan w/ shroud. I called Painless for a relay kit to wire it up and was told there wasn't one. That it would take (2) 70 A relays. One to get it up to low speed, and a second 70A to get it up to High Speed and then go back and shut down the low speed side or burn it up. What's the accepted procedure for wiring up this coling fan.........Thanks in advance