clutch fan vs. flex fan for fuel eco.
 

simple question im running a flex fan on my 350 with a 3 inch spacer. would i gain fuel mileage if i swap back over to a stock clutch fan setup?

Re: clutch fan vs. flex fan for fuel eco.
 

Absolutely

Re: clutch fan vs. flex fan for fuel eco.
 

^^^^ without a doubt.....

Re: clutch fan vs. flex fan for fuel eco.
 

....and maybe a little bit of hp!

Re: clutch fan vs. flex fan for fuel eco.
 

flex fans have a bad rep for falling apart and going threw the hood and rad. not so safe. id put back the stock one!

Re: clutch fan vs. flex fan for fuel eco.
 

yea everyone says that and we've had them for years and ran them past 7l rpms never a problem. Not to mention they cool better then clutch type. always have for me.

As for constant drag and freeing up accessories, yea they will and it will add maybe a hp or 2 if you're lucky and you might get a 1 mpg improvment if that.

IMO you want to save power and gas, get electric fans.

Re: clutch fan vs. flex fan for fuel eco.
 

When buying a clutch for a clutch fan do you want the regular one or a thermal one?
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Re: clutch fan vs. flex fan for fuel eco.
 

thanks guys for a quick responce, looks like im hitting the junk yard tommorow

Re: clutch fan vs. flex fan for fuel eco.
 

i got dual electric fans set-up and the radiator mount and all for them for 50$ all together,the front of the engine looks amazingly better,i imagine my gas mileage has rose,and they cool it great!

Re: clutch fan vs. flex fan for fuel eco.
 

no doubt e fans really clean it up underhood for sure. More room and cleaner.

Re: clutch fan vs. flex fan for fuel eco.
 

is that a kit you got?? and if so where at?? 50 bucks is cheap for dual fans!!

Re: clutch fan vs. flex fan for fuel eco.
 

I ran a flex fan once, never again...didn't keep the truck cool enough (and they look cheap). Put on a new stock clutch fan, NEVER had an issue. Couldn't tell a power or mileage diff with either, the peace of mind was "cool" enough for me. Elec fans are nice, but I prefer the simplicity of a clutch, and they are easier to put in. :)

Re: clutch fan vs. flex fan for fuel eco.
 

Would you keep a stock clutch fan in the case of a LS swap? (Sorry, not trying to hijack the thread, just weave it a bit)

http://67-72chevytrucks.com/vboard/s...d.php?t=419809

http://67-72chevytrucks.com/vboard/s...d.php?t=414820

Re: clutch fan vs. flex fan for fuel eco.
 

I had the exact opposite happen then what jeff had....

I had my monte carlo ss and nothing changed other then the fans, ran a clutch fan because everyone said how much better it was, wrong, the thing over heated. Now don't jump in and say oh the clutch was bad, again wrong, the clutch was working perfectly and kept my old mans 86 k10 cool with a/c all day long idleing in traffic. Mine jumped up to over 250 and popped the upper radiator hose. It blew it off the thermostat housing, and it was tight. I bought a flex fan and the car would never get past 180 or so in triple digit high humidity heat idleing in traffic.

The clutch fan done good in his truck, never a problem, the clutch fan in my 88 does great too, never had a problem with it.

The monte carlo had a small narrow blade 16 inch flex fan, and cooled good driving, but not in traffic, so I tried the clutch fan and it just kept creeping up while driving until it got over 250 and we were pulling off to shut it down and it started acting funny, then bam the hose blew off. I bought a wide blade 18 inch flex fan and it never got past 180 or 190 again. I had either a 160 or 180 t-stat in it I forget which.

So honestly I think if you got a flex fan and it works great, keep it, swapping might hurt it, like it did me.

If you got a clutch fan and it works good, keep it.

If you got a flex fan and it doesn't cool good, see what size it is, and the blades, narrow or wide, if they are narrow go with wide, if it's small get the biggest you can fit in your shroud.

If you got a clutch fan that's not working good, check the clutch or change it, if it works get a big flex fan with wide blades.

That's if you want mech. fan, if not then any of the above go with electric to save fuel and drag on the engine. I have yet to swap to electric but would like to, just afraid of it not cooling enough, but I know if you get the right fans it will. If they can cool a v8 camaro with like no grille opening for air, it should cool a truck with a huge grille area for sure.

Re: clutch fan vs. flex fan for fuel eco.
 

Chris, what you mentioned and I am sure you may know about...is that the fan (clutch or flex), needs to be positioned properly in the shroud. I assume this could be several peoples problems or phobias about each one way or another.

Re: clutch fan vs. flex fan for fuel eco.
 

Never gave it any thought, I can't really give you a good answer.

Re: clutch fan vs. flex fan for fuel eco.
 

Always run a Thermal clutch fan. You couldn't give me a POS flex fan, they are a crutch , If you have to have a flex fan to stay cool, then you have other problems.

Re: clutch fan vs. flex fan for fuel eco.
 

Always use a stock fan and fan shroud, try to get a RV or snow plow prep clutch as they will engage lower and harder for better cooling.

Re: clutch fan vs. flex fan for fuel eco.
 

dual electric's the way to go!

Re: clutch fan vs. flex fan for fuel eco.
 

Do you have pictures of your setup? I assume you pulled this from the junkyard. What was the original application?


Thanks,
Ed

Re: clutch fan vs. flex fan for fuel eco.
 

I have dual electric fans and they work amazing... Popped a fuse once, but now I carry spare fuses and haven't had it happen since. Idling up and down 4x4 trails in 90 degree heat, romping it on the same trails, cruising down the freeway, pulling up grades... always stays put.

Re: clutch fan vs. flex fan for fuel eco.
 

johnnypop what fans are you using. and what relay

Re: clutch fan vs. flex fan for fuel eco.
 

They're dual 13.5" flex-a-lite fans, the relay is built into/mounted to the fan shroud and came with the kit... they call it the variable speed control module on their website.