i have a six blade clutched fan i found in my 'inherited' pile of chevy parts. it's a little rusty but spins freely with no grinding/ just a little resistance.
it's much heavier than my stock 4 blade fan. my question,
will it provide better cooling? it'll look better (when painted). how is it suppose to spin? are bearings accessible?
thanks!
application is s/b '70 with headers

A working clutch fan will generally cool better because of more blades set to pull more air thru the radiator. It engages when it senses a rise in temp and disengages when not needed giving a quieter ride and improved mpg. On a cold start you should be able to hear it and feel a strong airflow and after a minute or so it will die down.

You can rebuild them also. The clutch part should be available at most auto parts stores.

Although they typically offer better cooling another thing to consider....

That's a lot of weight hanging on the end of the water pump. Along with the belt tension a lot of strain is put on the pump bearing thus causing it to fail sooner than if you ran a flex fan setup. Plus if HP is a consideration you may free up a few ponies by going with a lighter setup. Just my 2.

Every one above is right. But if you have a BB car with pwr and ac in a hot summer climate, the factory 7 blade and clutch are manditory. Yes, it puts more strain on the water pump, but the cooling is more important. Especially if you are an old fool like me who demands ac AND performance from the same car.

In my opinion, go with the clutch fan. I used to run the flex fan and boy was it loud! I am planning on the 7 blade with thermostatic clutch in my project. I also used to not have the shroud, which is a must.
John Walker

i wonder if it's missing parts. i don't see much i can "rebuild" on this old thing.

maybe im wrong but i thought the clutch was so it wouldnt drag the engine down at high rpm where you usually dont need a fan because you are also at high speed.

mike

Mike, There is a fan clutch that uncouples based on rpm instead of temperature. I tried one on a BB and did not care for it. There was more drag at everday driving speeds and when I would tow at highway speed my truck ran a little hotter than I was comfortable with. Philip