Flex Fan for Viscous Adapter ?

[Vermont Rock]

Have a crack one of my OEM fan blades and would like to upgrade to an aluminum or stainless flex fan, but can't find one that attaches to the original viscous adapter. Does anyone make one ? Is a direct attachment a better way to go ?
Thanks, Rocket

 

[1968RRTEXAS]

I believe most people use a spacer.

http://www.jegs.com/p/Flex-a-lite/Flex-a-lite-Fan-Spacers-and-Adapters/747389/10002/-1

 

[Grabinov911]

So... JUST LAST NIGHT I went through this same thing - sort of. I have been running my 493 stroker with a Flex-Fan attached directly to the water pump with an aluminum spacer. I have been looking for more efficient cooling and a way to quiet some of the fan noise at high RPM. I have a Wizard radiator which is so effective that I really need much "less fan" than I did using the stock 26" radiator. Was thinking of going w a Wizard electric fan system - the ultimate way to "turn off" the fans at high speed - but I have (had) a stock fan and viscous adapter sitting on the shelf, bought new for my 383 a few years ago but never used on the 493.

I decided to mount the Flex Fan to the coupler to have the advantages of both. I learned a bunch of things. First, the Flex Fan and spacer (the spacer I have) is almost exactly the same "depth" as the stock fan w the viscous clutch - about 3.25". That's a good thing. Second, the Flex Fan has a solid center with a 5/8" or so hole drilled in it to accept the centering lug on the water pump. The stock fan has a large 2" hole in the center to allow it to slip over the flange on the viscous clutch. There is no way to use a Flex Fan on the stock clutch setup.

So... I just mounted the stock fan and clutch to the water pump and buttoned everything up. The car runs, that's for sure. No interference problems w the fan and the radiator, etc. I drove the car a little this morning and it ran right on the 180 degree thermostat, but it was cool out. It WAS quieter at highway speeds - I assume because the fan was basically freewheeling rather than being driven at 3,00 RPM.

We'll see if this setup works. Does anyone know if there's anything "wrong" with the factory fan from the modern-cooling perspective? As in, would someone knowledgable say "Oh I'd never run one of those old things. They're way too ????"

 

[68 Sport Satellite]

I'm running a factory 7 blade fixed fan and mine cools fine. Normal driving stays around 170-180. I'd like it to stay below 210 in stop and go, but I've been told it's fine. I have no shroud, but when I finally add one it should be good to go.

I've heard many say a factory fan cools great if you have a good rad and correct T-stat. Adding a bottle of water wetter helps quite a bit too. It helps the water actually "wet" and make better contact for heat transfer with the tubes.

 

[monaco66coupe]

I have to bring up my problem with flex fans. The Blades sometimes detach. Last year in this area a guy was tuning up his Camaro, revving up the engine, when a blade detached. The Owner was under the hood, and it Killed him Instantly, when the blade hit him in the throat. In front of his wife, end of story.

 

[68 Sport Satellite]

I almost ran a flex fan, but I read too many of those same stories so i'm sticking with the factory steel fan. I'm surprised VermontRock had a crack in his original factory fan. I've never heard of that happening...good thing he checked.

 

[PurpleBeeper]

I'm running a factory 7 blade fixed fan and mine cools fine. Normal driving stays around 170-180. I'd like it to stay below 210 in stop and go, but I've been told it's fine. I have no shroud, but when I finally add one it should be good to go.

I've heard many say a factory fan cools great if you have a good rad and correct T-stat. Adding a bottle of water wetter helps quite a bit too. It helps the water actually "wet" and make better contact for heat transfer with the tubes.

Just a little note on Water Wetter..... I'm an antifreeze scientist (seriously) and I've tested the claims of water wetter....BOLONY! The "trick" of Water Wetter isn't the "low surface tension" idea on the bottle (fyi - Water Wetter in water only measures 46.60-48.30 dynes/cm2, similar to Hyper Lube). The "trick" is that water has a higher heat capacity & better heat transfer properties than 50/50 water/ethylene glycol. Water by itself corrodes the metal in your engine & cooling system & Water Wetter adds the corrosion protection chemicals that normally come in antifreeze. If you have iron heads/block/water pump housing the stuff works great. HOWEVER, when testing vs. aluminum, Water Wetter does TERRIBLE & aluminum parts get eaten away (I've done laboratory testing on this). I ran Water Wetter for many years, but once I got my test results, I took it our of my Mustang street/strip car the next day. To be fair, it does provide very good corrosion protection for iron/steel/brass/copper/solder. Royal Purple's "Purple Ice" & Lucas "Super Coolant" do much better protecting aluminum.

Also, Water Wetter (& all the similar products) don't do anything that I can measure when added in addition to 50/50 antifreeze. To get real improved cooling (20F-30F based on my testing), you need to use it with water only (preferably distilled or deionized).

 

[68 Sport Satellite]

Thanks for the info! I truly appreciate it as I have recently installed an aluminum rad.

Just a little note on Water Wetter..... I'm an antifreeze scientist (seriously) and I've tested the claims of water wetter....BOLONY! The "trick" of Water Wetter isn't the "low surface tension" idea on the bottle (fyi - Water Wetter in water only measures 46.60-48.30 dynes/cm2, similar to Hyper Lube). The "trick" is that water has a higher heat capacity & better heat transfer properties than 50/50 water/ethylene glycol. Water by itself corrodes the metal in your engine & cooling system & Water Wetter adds the corrosion protection chemicals that normally come in antifreeze. If you have iron heads/block/water pump housing the stuff works great. HOWEVER, when testing vs. aluminum, Water Wetter does TERRIBLE & aluminum parts get eaten away (I've done laboratory testing on this). I ran Water Wetter for many years, but once I got my test results, I took it our of my Mustang street/strip car the next day. To be fair, it does provide very good corrosion protection for iron/steel/brass/copper/solder. Royal Purple's "Purple Ice" & Lucas "Super Coolant" do much better protecting aluminum.

Also, Water Wetter (& all the similar products) don't do anything that I can measure when added in addition to 50/50 antifreeze. To get real improved cooling (20F-30F based on my testing), you need to use it with water only (preferably distilled or deionized).