7Deuce

When I purchased my car the previous owner had the following setup...




It's a flex fan with a spacer. No clutch or anything like that. Basically my fan is always turning when the engine is running . It seems to be functioning fine (temps never get above 190 degrees). What I don't like is how noisey this set-up is. Also, in the research I've done it appears as if this set-up creates more parasitic power loss than a proper fan/fan clutch.

I'm thinking about replacing my current set-up with a normal fan and fan clutch. Is this a good or bad idea?
Any suggestions on what parts to use (type of fan,size of fan, # of blades, type of fan clutch, etc) appreciated.

dennis

not sure of the year, but that steel shroud fits 68,69 and some 70.(small blocks). I can see a replacement water pump, which I'll assume has a larger bearing shaft. Now comes the can of worms. IF you need the smaller wp bearing shaft,(pre 71), you'll need to change the pump,wp pulley, possibly the crank pulley, fan clutch and fan.

Now if you are OK with the larger wp shaft, then the pulleys/pump you have should work. Then you'll need to find a fan clutch/fan for the larger bearing shaft.(71 and on).

Don't ask me how I know. Post the year, engine, options,(PS, A/C), and I'll try to help.

markdtn

Yes, great idea to replace. Other than a fixed fan a flex fan draws the most horsepower of any fan. And it makes that Zzzzzzzzz sound. I would either get the stock clutch and fan for your car; try Paragon or some of the other catalogs, or better yet an electric fan. Do a search for electric fans, there is plenty of info in the archives.

7Deuce

It's a 72. No power steering/no air conditioning. Obviously not everyting is original and I'm not looking to return it to stock original. I guess I would want to keep this as simple as possible. Keeping the water pump, etc. I have now and just putting on a fan/fan clutch.

An electric fan would be nice but I'm already digging a deep hole $$ wise with some other things I fixing so I'm don't think I can swing electric fans right now.

icanfixitforyou

Go for the stock fan and fan clutch assembly. I USED to have a flex fan, no more, same reasons too noisy.

BarryK

go back to stock. stock fan / fan clutch works fine.
in additional, flex fans tend to break off blades which is bad enough, but when the blades goes they tend to take large chucks of fiberglass with them.......

disclaimer: before flexfan users start flaming me, I'm not saying all flexfans will break, just that there is a higher risk and percentage of these things breaking. i've never heard of a stock fan breaking off blades.....

dennis

Ok here's some NCRS tech board fan clutch info to get you going. You mainly want to get it all to fit with what you have now. Not that it needs to be numbers matching:

For 1972, a different fan clutch was used. That clutch was GM #3991426. This was kind of an "odd-ball" looking fan clutch. It was a Sweitzer-manufactured clutch with the "bi-metallic" thermostat. That part was like all other Sweitzer-manufactured fan clutches. However, this one had a large "dish-like" perimeter around the finned center section. This fan clutch was discontinued many years ago without supercession. However, the GM #460742 can be used to replace it. That fan clutch was also discontinued within the last year, or so, and replaced by the GM #88961763. I don't know what the configuration is of the latter clutch, but it would be a 100% functional replacement for all 1971-73 Corvettes, regardless of engine

Here's a little fan info:
http://www.ncrs.org/forum/archive4.cgi?review=1490

7Deuce

I checked on the Paragon website. For a stock fan it's something around $100 and the fan clutch is like $125. There must me cheaper alternatives, aren't there?

Thanks for the info Dennis, that gives me a place to start.

Fevre

Might want to also get the second belt for the wp and crank in case the alt belt breaks you still will have the wp spinning

ThunderMaker

I just removed my Flex fan from my "79 and there is a noticable power increase and the engine is a lot quieter, i wish I had done this sooner. I have a brand new never installed OEM stock fan that I'll let go cheap if you want to go the stock clutch/fan route, let me know if you year model is similar.