I have a 70 440hp a/c car so the fan is direct no clutch, and when cruising 50 mph or higher it is very loud, is that common? it is the 36" belt around fan and idler, i've always had clutch fans and don't remember the same noise from them, Also haven't installed shroud yet either, would that make a difference?? thanks

Not sure about the noise. Sounds plausible. I've had flex-fans on vehicles in the past and some were noisier.

In any event, I would visually inspect the fan, pullies, belts for wear, cracks, bent blades, balance.

Would also add an aftermarket fan-clutch if space allows. That may "fix" the noise, and it should improve fuel-economy, performance, wear on engine.

factory fan? i thought most A/C cars had clutch fans? maybe its spinning too fast? [pulleys wrong?] dan

Fan noise at 50 mph ? .. that is costing you power and MPG. PLUS .. in most cases you do not need that fan-assist in moving the air for cooling past 15 or so MPH anyways. The forward movement of the car is enough to provide that.

I say broom-out that fan you have and put-on a REAL flexible flex-fan or better yet ...an electric "puller" fan.

Fan noise is mostly dependent on the width/pitch of the blades, a more agressive pitch moves more air but with the accompanying noise. A clutch fan with the same diameter/pitch as a direct drive will make less noise.

I'd change over to a clutch fan like most A/C equipped cars.

An A/C water pump spins at 1.3 times crank RPM. All A/C cars came with clutch fans for this reason. No wonder it is noisy, HUH? Your fan is a time bomb. Get a clutch fan on there before trouble occurs.

The fan i'm running is the 2863224. I thought thats what the source book said to run on 70 A/C cars? It's not a bad noise like somethings wrong just kinda like propeller spinning. I think i'll change orver to clutch fan. Try to keep underhood stock is why i used the 2863224, but maybe thats the wrong fan anyway?

Could well be the correct fan, but I believe that with the A/C option, the fan-clutch is included.

I run a fixed stock 4-blade fan on my 440, no shroud. Doesn't make any noticeable amount of noise.