electric fan. push or pull set-up ?
 

What is the best location for a pair of fans, infront or behind the radiator? I am considering a pair on seperate circuits in case of a failure.

behind the rad setup as pullers. Thats the way most cars are setup. I have a single black magic (wish I had gone with 2 smaller units but oh well) as a puller. Works very effectivly even in the hot summer heat. Doesn't come on very often, if ever, this time of year though. something you might consider is to put one on either side of the rad, one pulling, one pushing. Have one do most of the work and the other setup to come on only under extreme temps. Just a thought.

a pusher setup might be better just to get it out of the way, there is a TON of space infront of FB rads that just is totally unused...

that is something to think about, my fan sits very close to the water pump, if it ever comes loose it would be a mess.

Pusher fans are much less effecient than pullers. Running it in front of the rad may cause cooling problems.

Its for an intercooler!

I got an idea, two as pushers, and two as pullers! Just kidding, but where do I get the dual pulling electric fans(the smaller ones)? I have been interested in this mod for a while, and was wondering what type of car the duals come off of. Thanks in advance.

FD Twin Fan setups are quite nice. 2 Speed Too.

Meh, I had mine set up as both and there was no noticeable difference.

pusher is better. remember that they are air cooled. if its set as a puller, then the fan motor will collect dirt and dust which in the long run, it will make it over heat. Similar problem with residential and light commercial AC units (condensers).

Other than that, I have tried both pusher and puller set ups, I didnt notice a difference using a derale 16" fan.

I am thinking about a pusher type setup, since way too much space is avaliable is in front of the radiator especially when you removed all the AC related stuff. And I would like to make more room in the engine compartment, plus don't have to worry about the fan turning itself on while work on a running engine.

??? I have never herd of this before, and it just doesn't make sense. A puller is situated behind the radiator...If anything the radiator itself will act as a filter keeping large junk from ever making its way into the engine bay.


Rx7carl is correct. Pushers are much less effective than pullers. Now some of you might have had a system that was efficient enough to get away with only a pusher...but I would never take that chance. And I garentee you no automotive fan manufacturer would ever recomend only a pusher.

There are some flow loss and venturi effects...but the big problem is taking advantage of the car moving at speed.

The best way I have been told to visulize the issue is to picture the fan shroud as a funnel and spray water from your shower over it (water acts like a wall of air as you drive forward and the radiator is at the large side of the funnel). If the water comes from the large side of the funnel you capture all the water that lands in that large area. If the water comes from the small hole side of funnel you only get a streem the size of the small hole thru the big hole in the funnel.

Was that at all clear?

It doesn't matter where the fan is. A pusher fan is just as big of an air restriction as a puller fan and are both subject to the exact same effects. To whoever said it, you didn't see a difference between a pusher and puller because the only difference is location. Everything else works the same. It is no harder for a fan to push air through a radiator or intercooler than it is for it to suck air through. Like I said a restriction is a restriction. go look at some high end BMW's and see where their fans are. BTW, Look through the grille!

Yes, but every BMW I've seen that has a pusher style fan, also has a crank fan acting as a puller.

puller will pull dust and dirt along with air. Do you think the dust will just pass the fan motor? Wrong. A good example is the fan clutch on a mechanical fan (stock). Check how much dirt is collected over time.

I have worked on so many air conditioning units that that is the main cause of failure on electric motors.

OK, from all this i am getting htat it is fine to use a pusher, thats what i was thinking about diong since i have a 3 liter taurus fan already. It wont fit as a puller, but a pusher it would fit. Will it work fine?

The fan motor is always in the center of the stream of air unless you are talking about a different type of fan like the setup they use to vent paint booths or anyware else that might have flamable gasses.

With the pusher fan the flow first goes past the motor than the fan blades then the radiator. With a puller it goes thru the radiator then the blades then past the motor...nomater what the air has to go past the motor. But if the motor is the last thing to see the air then some of the dust will be filtered out on the fan and radiator before it can even get to the motor.

I'm not debating wether dust or dirt on a motor is bad for it...of course it is.

The only thing I can see that would account for a dirtier motor when using as puller fan is relates to its ability to allow a larger amount of air thru the system therefor also drawling more dust?

OK, say no dust but what about the heat. you cant cool a electrical motor with hot air. Im referring to long time use.

Funny shit but my RX-3 is running a pusher while other, 85 FB, is a puller.

A difference in dust? You guys can't possibly be serious and still hold a straight face at that can you? Show me an engine bay that doesn't get dusty. If it passes through the radiator it is still there. What is this radiator filtering crap? If the radiator stopped dust and dirt, it would completely clog and not cool the car anymore. You should see how much dirt can collect on the fan blades of your fans. It works the same as dust on a ceiling fan. Not a valid argument.

The heat on the electric motor issue is the single most valid point here since it is the only thing that may be affected by the location. Engine cooling, aerodynamics, and dust/dirt filtration are not affected if the same fan were a pusher or a puller so long as ducting is equal but heat on the motor may be. That I agree with.

Guys, I have read a lot of intresting opinions etc on this forum, but this thread seems full of BS...
It's not because a fan is a puller or pusher that it would be less or more effective. You must simply see what works best for your application in sense of praticality. Like: is there engough space for the fan behind the rad? Or do you maybe prefer the looks of the rad without seeing the fan? Then, you just buy a good fan, in other words one with enough flowing capacity.
A Kenlowe 8" fan will push 1002CFM/hour , or it's 8" puller variant will be the same dimensions and, indeed pull 1002cfm... I rather believe the Kenlowe guys (best fans available in the UK) then the people on this forum, sorry.
Just check this link:
http://www.kempower.be/FANS/fan-main.htm
It's a Belgian site, but what I want to show is that push or pull doesn't matter in terms of being effective.
Like rotarygod above said: the only difference might be the fact that the pushr motor might be running a little cooler, which is a plus for that setup. Other then that: it doesn't matter.

Puller, so I don't push my luck.

As long as one is there, at least when it gets hot. I only use mine (elect on a manual switch) in traffic, other than that there is no need. Dont need the extra horsees in bumper to bumper anyway.

Yea, thats the only time mine comes on, traffic, or if its sitting somewhere idleing. I don't think its ever come on while moving, even up a hill or something.

That's true, mine hardly ever kicks in either. Only in traffic jams or so. But I do like it to be in there anyway ;)