Clutch Fan VS. Flex.....

[hpproron]

OK, here it is...Clutch Fan or Flex Fan? I'd like to hear the juice on what YOU believe is the best option...

My application is a 1 ton 4X4 with a (soon to be finished) 496 stroker.

I have two electric fans in front of the radiator presently, and of course, the stock clutch fan...

I am very concerned with overheating this big-block beast, so let me know what you think

Ron

[dkn1997]

I can tell you in my situation, that after trying absolutely everything I could think of, including a brand new be cool direct fit radiator, the switch from clutch to flex was the only thing that cooled my ride off! tried two different clutch fans, no luck.

[usdart]

Just my opinion..Flex fans are all hype and no cool. Not to mention being as sharp as knife blades. I barely touched one a few years ago and sliced my hand about 2" and 1/2" deep.

Car engineers spend millions testing and I am not convinced these after market flex fan manufacturers spend as much on research to back up thier claims.

Don't get angry fellas..It is just MY opinion.

[6 packin]

The factory fixed fans are the best cooling fans period. No clutch,flex or electric fan can match the cooling power as a fixed fan. It would half to be a high $$ electric to do it. They do tend to rod some power may be 5 horses, but who can tell? When you have a stroker big block whats 5 horses. Your breather/aircleaner will be robbing you more power than that.

[deadhorse66]

But, if the clutch is working properly, the viscous fan will work like a mechanical when the engine is hot. Viscous, not clutch. Yes? I kind of like the stainless fanblades with the larger blades on them. None of that flimsy aluminum crap that flattens out at high rpm, but a good fan that flexes a little as the engine revs, and doesn't turn into a big shiny pinwheel when you spin it fast. They have them in Summit, and I think they are made by Flex a lite, or whatever the company is that makes those little gay ones. The black magic electric puller fans pull a whole lot of air, too. Since you have a four-wheeler, you may not have enough air coming across the radiator when you get down on it in a mud puddle. A big electric would definately help there. You may want to look into them.

[dkn1997]

I was looking for a fixed fan, and the flex was cheap, that's why I got it (painted it black so it does not look like one of "those little gay ones")

my car would idle hot, but cruising would be very cool.
I assumed that the clutch fan I was using was not moving enough air through the rad at idle to cool properly for my application. the flex fan immediately made a huge difference, but I assume any "fixed" fan would have.

was it possible that I got two "bad" clutch fans? one was the mp viscous one, and the other was a thinner one I got from mazzolini racing. can only be two things wrong, either bad blade design, or both clutches were not locking the fan enough at idle.

anyway, I was just sharing what happened to me, I was not trying to endorse the flex fan. Believe me, I would rather be running a clutch fan, just did not work out for me.

[PLUM_72]

ELECTRIC IS THE BEST!! If the factory can cool a V10 Viper with an electric fan, you should be able to cool a built small block or big block. Its all in selecting the right fan!

[hpproron]

This is good guys!!! Keep the feedback comin'!

My direct experience is this. When I rebuilt my Ford 400 (in a '79 Bronco), I put a flex fan on it and all seemed well. But again, I want gauranteed security once I get the Mopar beast rolling.

I did not think about a fixed blade (non-aluminum). I'll look that info up at Summit, as suggested.

I'll keep checking to see more opinions.

Thanks again!

Ron

[5th_Ave_Sleeper]

I really like the flex a lite i put on the 5th. its the black 18" one made from some kinda composite crap, and its not sharp like the metal flex fans. its good up to 9000 rpm so they say. i had mine to 7000 (thats when the cam lobes and lifter bases melted)
And boy does it move LOTS of air! my .060" over 10.5:1 360 didnt get over 180* after i put that fan on there.
As Martha would say; "Its a good thing"
5th

[JVMopar]

For a 4x4 and electric fan is a must if you are going to go mudding. If you get that engine mounted fan into water it will pull itself straight into the radiator.

[dkn1997]

I did not think about a fixed blade (non-aluminum).

Funny thing is, that most mopars I see at the local cruise night have fixed fans and they look factory.

they Must be doing something right.....

[mtrv8n]

I run an 18 flex fan, and it moves way too much air at idle..hehe.. its NOISY!

Actually, it works great, I have a crate 360/380, running A/C in 95 degree humid NYC traffic, no overheating problems. Oh, I also use that redline water wetter stuff.

On 9/11, I had driven it to work,( in Brooklyn, 5 miles from WTC) and at about 11 Am I drove downtown to pick up my sister in law from work, piled her four friends in for a ride, and drove in heavy traffic all the way out to Long Island, and back home.
Not a peep from the temp guage.

I shoulda taken some pics of it that day, covered in ash..

[deadhorse66]

Originally posted by PLUM_72
ELECTRIC IS THE BEST!! If the factory can cool a V10 Viper with an electric fan, you should be able to cool a built small block or big block. Its all in selecting the right fan!

*remember that the Viper is all aluminum, and that much more heat is lost through an alu. block than iron*

I doubt a Viper's cooling system would cool a 500 inch mud machine. But I would recommend another LARGE electric on the puller side for a 4X4 app., due to low vehicle speed and the point that JV made. (I never really thought of that, but good point, bro)

[hpproron]

Well, here we are several days later and it all seems to be adding up just fine. I believe I am going to just keep the stock clutch fan on there (save some $$$ now anyways), and utilize the two electric fans as a back-up.

Thanks again gentlemen!

Ron.

[70 net440]

Well, here's my two bits. I've had a factory fixed on my Coronet since I got it. The car always ran hot until I put in a new stock rad. from Year one. I also have added a shroud, Milodon water pump, and water wetter. The temp stays constant in 30 degree winter to 100 degree summer. For the trip to Kool April nites i installed the MP viscous package for some quiet. The car ran at the same temp all the way down the freeway. When I stopped during the cruise to fuel up the temp went up about 10 to 20 degrees and wouldn't come down in the gridlock. As soon as I got moving the temp. dropped back to normal. It was pretty cool this weekend so I don't know how it will work in the heat, but so far I'm happy.