89Broncobob,
Torque first makes a good point about the inneficiency of using an electric fan, and the simplicity of a clutch fan is hard to beat, but if you do any 4 wheeling where you get into deeper water, you will definiely want to go with the electric fan. While the serpentine belts are easier to take off and put back on than Vbelts for a deep water crossing, doing so eliminates all your accesory drive and makes it critical that you get across in a hurry. It is a heck of a lot easier to shut power off to your fan until you get across the creek or mud-hole.
If you never get into the wet stuff while wheeling, stay with the stock fan clutch and add a pusher fan with the temp/A/C controls mentioned above.
T.A.N.S.T.A.F.L.

 

thanks ..thats what i will do .I dont go in deep water .but it is very hot in south Florida, and towing or 4 weeling it gets hot so i will put a pusher fan on .i have on that came from a mustang , were do i put it and i assume it should blow in ..is that right .i think i might just put it on a toggle switch ...

 

You would mount it between the grill and the A/C condenser. Toggle switches are simple, but depending on the current draw of your fan, you might want to hook up a relay to the switch instead of directly to the fan.
What you won't want to do is use those tie wraps that go through your radiator to secure it. Build a bracket with isolators to keep it from causing more problems than you fix.
The fan you pulled from the Mustang, is it a pusher fan originally? If not, you will maybe have clearance issues between the grill and the condenser in order to make sure the air is flowing the right way. also. because the motor will offset the fan blades farther from the radiator, your air moving efficiency will probably suck, not blow as desired. most pusher fans that I've heard of were designed that way from the start. You could be charting new territory.
T.A.N.S.T.A.A.F.L.

 

hmm i will have to check on that ...

 

Has anyone used these fans? Looks like a nice setup. I think you have to purchase a controller as well.

Derale 26" Dual High-Output, Electric Radiator Fan-and-Shroud Assembly - 4,000 CFM Derale Radiator Fans D16927

 

Well I'll give my input on this subject since I do have dual flex-a-lite fans installed on my Bronco for a few years now.

I originally installed them because I though I may get slightly better MPG and maybe a little more HP etc.

Did I get any MPG improvement? Not really, not any I noticed regularly, and I pay pretty close attention.

Did I get more power? No, not really, at least for the most part. I will say though, with my AC on, it doesn't bog down as much. I noticed with my AC running before, my truck would seem "tired" after a little while, and I always heard the stock clutch fan loudly. After the Electric fans, that never happened again.

Now despite not noticing more power or better MPG, I still am glad I installed the fans. You get A LOT more room in the engine bay with the stock fan out of the way. I can't count how many instances where I saved a bunch of time because I didn't have to take the stock fan off to work on something or another. The engine bay looks a lot cleaner in my opinion also with it out.

Like Greystreak said, I think most of the advantage of not having mechanical drag from the clutch fan gets negated by the electric draw the alternator has to keep up with.

With how long I've driven, I think its SLIGHTLY better with the fans performance and MPG wise, but not enough to justify buying them, (especially if you go with the fancy flex-a-lite 295 fans like I did.)

I will say, to keep this in perspective, most people say the K&N FIPK kits for these trucks (air intake kit) are a waste of money and you don't get much HP out of them. I ended up installing the FIPK kit anyways, and I did feel the difference it made (although very small, but I did get 1.5mpg boost.) That was less money that a flex-a-lite fan, and has a significantly bigger impact that the fans would.

However, if you want more room in your engine bay, less strain on the water pump, and a little more control over your fans, it may be worth it. I wouldn't consider it for a performance upgrade though. I am happy to have them too, but don't count on noticing any difference with them.

EDIT: Haha.. it's late, I didn't realize this thread was 11 years old until I saw the new thread started. Well if anyone stumbles across this from searching the internet, the above info is what I have to say!