Ok, I put my radiator in the back of my rig. I want to make my black magic fan a pusher instead of a puller. Anyone done this?

I think you just flip the blade over and reverse the polarity of the wires, that's how mine was, not a Black Magic though.

The fan has a control module on it. I *could* reverse the wires from the module to the motor though..... I just want to see if anyone has done it (and it worked)....

I have a similar fan and yes it works just fine if you switch the wires. I cut off the wire ties to give a littl eworking room after I was done switching the wires, I put two wire ties back onto the bar to hold them in place.

Every thread needs a picture!

Like Wilson said:

From here: http://www.flex-a-lite.com/auto/faq.htm

Q)Is there anything I can do to make my model # 150 a pusher?

A)Yes, turn the blade over and reverse the polarity of the motor wires. Note: the fan does not run as efficiently in a pusher mode.

Q)Which type of electric fan is better, a pusher or puller?

A)For primary use a puller. For auxiliary use a pusher.

I assume you have this one: http://www.flex-a-lite.com/auto/blackmag.htm

Yeah I was gonna say, heh, dont do both. that defeats the purpose.

Originally posted by Chris Geiger
If you switch the wires, don't flip the blade. One or the other.



Originally posted by hey its daver
Yeah I was gonna say, heh, dont do both. that defeats the purpose.


Huh? :laughing:

Ummmmm guys if you turn a fan blade around it DOES NOT make the air go the other way!
Think about it, the pitch is the same either way it's facing what does change IS the airfoil on the blades.
All fans are either designed to be a clockwise OR counterclockwise rotation so if you reverse the fan wires you still do need to reverse the fan so the leading edge of the blade is facing the air intake side.

[edit]
Simpler explanation, if you have a threaded rod the threads are right hand no matter wich end of the rod you're looking at.

Well on mine I switched the wires and left the fan alone. The blades on mine are flat, not airfoil shaped.

i vaugly recall reading in my instructions that came with mine a warning not to use it as a pusher. put i think you should try it for carnage. it would be neat to see you on the first obstacale with a geyeser of hot water blowing out the back. :flipoff2:

seriously. i remember reading the instructions and they said not to use it as a pusher.

Instructions? :barf:

lets see your application (ie show us your rig Lance ;) )

I never even thought about the blades, I run mine as a pusher and I can feel a ton of air but it does have those s shape or whatever type blades..

are you turning into a mud bogger on us :flipoff2:

Originally posted by ForestCam







Huh? :laughing:

Ummmmm guys if you turn a fan blade around it DOES NOT make the air go the other way!
Think about it, the pitch is the same either way it's facing what does change IS the airfoil on the blades.
All fans are either designed to be a clockwise OR counterclockwise rotation so if you reverse the fan wires you still do need to reverse the fan so the leading edge of the blade is facing the air intake side.

[edit]
Simpler explanation, if you have a threaded rod the threads are right hand no matter wich end of the rod you're looking at.

Then why does my ceiling fan move air the other way when I use the reverse switch? I do not remove the blade.

Then why does my ceiling fan move air the other way when I use the reverse switch? I do not remove the blade.

STRAIGHT FLAT BLADES!

Originally posted by CJ


Then why does my ceiling fan move air the other way when I use the reverse switch? I do not remove the blade.

Just take a fan blade, look at it, turn it over. It will be obvious that it doesn't make any difference which way it's mounted, no matter if it's flat or curved. :rolleyes:
Reverse the polarity, thats different.

Fans are more efficient as pullers.

Originally posted by Bigburlynakedguy


STRAIGHT FLAT BLADES!


Exactly!

Ok with most fan blades you have a leading and a trailing edge with some sort of airfoil to the blade whether it be actually a true airfoil or a "hollow" airfoil (the blades are just curved kinda like these perenteses) unless they're totally flat like Chris' fan and not tapered or offset.

So if you try to rotate a blade backwards (either by reversing the motor or reversing the fan) you loose a lot of efficiency because you are fighting the "lift" caused by the airfoil on the blade (see picture below).

So if you take a puller fan and just reverse the motor (and if the blades aren't flat) even though the angle of the blade causes air to be pushed through your radiator the airfoil of the blade is causing some of the air (the lift) to try to go in the oppsit direction causing swirling and actual cavitation in the airflow resulting in far less efficient cooling.

Hell I just took a look at the box fan sitting here and even that has a definate leading and trailing edge to it and it even has a slight airfoil to the blades themselves.

Dump the Black Magic and get yourself a fan out of a Ford Taurus. Nobody I know has paid more than $50 for one and the flow as much as any stock mechanical fan I've ever seen.

Squash

Now the question is do you know what causes that lift?

Also how do turbo props get reverse thrust? :D:D

Originally posted by JR
are you turning into a mud bogger on us :flipoff2:

:flipoff2:

Originally posted by ONETUFF76
Now the question is do you know what causes that lift?

Also how do turbo props get reverse thrust? :D:D

Bernoulli principle: Air on top of the wing is thinner, and less dense.

Turbo props produce reverse thrust by adjusting the prop pitch past 90 degrees. so the air is sent the opposite way across the prop.

Originally posted by ONETUFF76
Now the question is do you know what causes that lift?

Also how do turbo props get reverse thrust? :D:D


Yes :rolleyes: , air moves over the bottom surface faster then the top causing a low pressure area at the top of the airfoil which in turn causes lift.

Turbo props get reverse thrust the same way a piston driven prop would if it had a variable pitch propeller.

ACK! Chris beat me to it!:laughing:

Originally posted by Realsquash
Dump the Black Magic and get yourself a fan out of a Ford Taurus. Nobody I know has paid more than $50 for one and the flow as much as any stock mechanical fan I've ever seen.

Squash

make sure it's a two speed one!

Originally posted by Brandon
lets see your application (ie show us your rig Lance ;) )


My digicam is broke, and my new one is on backorder. :(

Originally posted by Old Scout


make sure it's a two speed one!

is that what that other wire is for? LOL

but why would ya use 2 speeds?

I can't find a good pic of my fan, I found it in the back of a van at the pnp so I dunno what it came from but it kicks butt esp for like $5 on half off day


http://www.rivercityrockcrawlers.com/TechReports/MoPower/engine/cooling/radback.jpg

Good job! :D:D

If you flip the balde over, you do have to switch polarity too. I put my fan in at 3 am last week and was disappointed that it was still a pusher, after flipping the blade over like the directions said. It worked fine at idle breaking in the gears and then driving from Chico to Kyburz last friday. But after five minutes on the trail, I had water flowing out the front of my grill. Somebody in our group had a similar fan and reminded me of the step that I missed (switching the polarity) With that done, it ran the rest of the day without any problems. The fan does move a lot more air as a puller than a pusher.

Very timely thread....;)

I too am mulling over the idea of moving my rad to the back of the truck. However, I have a series of questions / concerns with this and would appreciate any insight...

What safety concerns would have to be considered for eventual hot water leaks or roll-over spillage??

Where should the water lines be routed??

I´d assume that the lines would have to be somewhat oversized to compensate for the increased circuit length, right??

Could a normal stock water pump handle the additional load??

TIA

:beer: :beer:

Originally posted by Brandon


is that what that other wire is for? LOL

but why would ya use 2 speeds?

I can't find a good pic of my fan, I found it in the back of a van at the pnp so I dunno what it came from but it kicks butt esp for like $5 on half off day

Here is the one I have. The 2 speed ones are off of 87 on with the larger v6 with A/C

Originally posted by camo
i vaugly recall reading in my instructions that came with mine a warning not to use it as a pusher. put i think you should try it for carnage. it would be neat to see you on the first obstacale with a geyeser of hot water blowing out the back. :flipoff2:

seriously. i remember reading the instructions and they said not to use it as a pusher.

Just a FYI, my fan died a few days ago, so I've kinda been looking around. Maybe everybody already knows this, and maybe it won't be of any help at all, but I just thought I'd mention that Flex-a-lite has instructions available in .pdf format for all of thier fans on thier website. They also have a live help chat room, but I'm not sure when it's closed or open. Worst case, they have a 800 # on the site.

www.flex-a-lite.com

I just used a pusher from a Benz, nothing like a factory pusher fan, and being a benz, i hope it will last a long time

Originally posted by Old Scout


Here is the one I have. The 2 speed ones are off of 87 on with the larger v6 with A/C

What are the dimentions of those? How wide and how thick?

Hello... Anybody there?

I have one in my shop I'll sell you, I didn't feel like messing with it, so I bought the other fan. It's a two speed and is about 19x22x4, I believe. It fits really nicely over a toy radiator.

4" thick eh? That's not going to work for me. Thanks anyway.

For a good fan for a willys, try one of these. My plastic bladed pusher is missing a lot of chunks from gravel flying into it. I've got one of these on order. 2950 CFM for $84 at Summit

http://www.permacool.com/Catalog/CatImages/PG17-C1.gif

Originally posted by oldjeep
For a good fan for a willys, try one of these. My plastic bladed pusher is missing a lot of chunks from gravel flying into it. I've got one of these on order. 2950 CFM for $84 at Summit

http://www.permacool.com/Catalog/CatImages/PG17-C1.gif
Any dimensions for that fan. I need a fairly shallow, high CFM fan.

Originally posted by Rogue Bronco

Any dimensions for that fan. I need a fairly shallow, high CFM fan.

14x14x4 www.permacool.com