Flex Fans
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
Flex Fans
anyone have experience with using the lightweight flexfans that "warp" with changes in rpm. they only weigh a couple of pounds. any noticeable increase in performance (or cooling) by eliminating the stock fan and clutch? how about the electric "puller" fans such as those from BE COOl?
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
that's good because the literature claims they actually INCREASE horsepower due to 1. less weight and 2. less centrifugal force when turning (no clutch fluid trying to fly outward creating resistance for the engine to turn).
wonder if anyone has actually tested this on a dyno???
wonder if anyone has actually tested this on a dyno???
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Do a search on fans. Car Craft had an article in May 2000 I believe. I have it at work. I posted the results within the last 60 days I believe. Bottom line is that you are better off with an electric fan or a viscous fan over a flex if I remember correctly.
Here it is:
Car Craft test, May 2000 issue, page 50-51.
No fan=496 hp
thermal clutch fan 487 hp
HD thermal clutch fan=476 hp
non-thermal clutch fan=485 hp
plastic flex fan 460 hp
HiPerf flex fan 476 hp
lo Profile flex fan=466 hp
6-blade rigid=449 hp
electric fan=494 hp
4-blade rigid=473hp
Here it is:
Car Craft test, May 2000 issue, page 50-51.
No fan=496 hp
thermal clutch fan 487 hp
HD thermal clutch fan=476 hp
non-thermal clutch fan=485 hp
plastic flex fan 460 hp
HiPerf flex fan 476 hp
lo Profile flex fan=466 hp
6-blade rigid=449 hp
electric fan=494 hp
4-blade rigid=473hp
Last edited by markdtn; Nov 23, 2004 at 09:18 PM.
Pro
Joined: Oct 2004
Posts: 567
Likes: 0
From: Springhill Kansas
I have a flew fan and hate it! It makes a lot of noise and if you think about it, there is no reason for the fan to be spinning when you are going 80 down the highway. I have a set of electric fan i am going to put on just got to build the bracket for um. Electric fan is the way to go!!! 
Burning Brakes
Joined: Oct 2004
Posts: 1,038
Likes: 0
From: Grants Pass Oregon
Flex Fan
Well, i got a high perf flex fan and an electric fan, I may go with the flex for ease of installation, I don't have a plastic shroud though. I havn't decided to use an after market metal shroud or not yet...Its a conundrum........LOL 
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
For many years I used the 18 inch stainless steel "10,000 rpm" model flex fan. It corrected the problems of the stupid heavy stock clutch fan. The clutch fan that came on L-82's were noisy when you had a high rpm motor and when you needed the cooling they went into free wheeling mode.
Probably saved 10 -12 pounds. What that Car Craft article doesn't say is: the clutch fans are a real resistance to up and down excelleration by shear rotational weight. The odd blade placement is not balanced so your water pump seals and bearings go out. they cavitate at higher rpm. For truck motor they do good. just don't use one on something that do over 5500 rpm
Probably saved 10 -12 pounds. What that Car Craft article doesn't say is: the clutch fans are a real resistance to up and down excelleration by shear rotational weight. The odd blade placement is not balanced so your water pump seals and bearings go out. they cavitate at higher rpm. For truck motor they do good. just don't use one on something that do over 5500 rpm
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Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by gkull
Probably saved 10 -12 pounds. What that Car Craft article doesn't say is: the clutch fans are a real resistance to up and down excelleration by shear rotational weight. The odd blade placement is not balanced so your water pump seals and bearings go out. they cavitate at higher rpm. For truck motor they do good. just don't use one on something that do over 5500 rpm