63 vette replacement fan

[Richard S.]

I have a spare clutch fan for my 63 340 HP vette. The clutch has an external spring to control fan cutout at higher RPM/temp. It has no obvious oil fill area as with the orignal one. I would like to know how to lock out the spring action so that during hot summer months the fan will stay engaged full time. I am not worried about loosing HP.
Thanks
Rich

[Duke W.]

Re: 63 vette replacement fan

There is no reasonable way to make a clutch fan "full time." If you want to do so buy a fixed or flex fan.

But keep in mind that the Corvette cooling system was very "high tech" for its time and has a lot of premium parts like the viscous clutch fan and aluminum radiator. It works very well, and cannot really be "improved".

If the system is in proper working order it should keep operating temperatures in the range of about 180 to 230 at the top end in extreme condition, which is the same range than modern cooling systems run.

Duke

[Duke W.]

Re: 63 vette replacement fan

There is no reasonable way to make a clutch fan "full time." If you want to do so buy a fixed or flex fan.

But keep in mind that the Corvette cooling system was very "high tech" for its time and has a lot of premium parts like the viscous clutch fan and aluminum radiator. It works very well, and cannot really be "improved".

If the system is in proper working order it should keep operating temperatures in the range of about 180 to 230 at the top end in extreme condition, which is the same range than modern cooling systems run.

Duke

[Wayne M.]

fan trick

I think this is the trick: (might have been in an old RESTORER article)

Slide (by pulling forward) the end of the spring out of the fixed slot.

Rotate spring counterclockwise (viewed from the radiator) until it stops.
This should mimic hot temperature movement on the spring and attached internal valve, even when temperature is ambient.

It's worked for me, and that's how I remember it

[Richard S.]

Re: fan trick

Thank you for the tip. Does rotate the spring CCW until it stops mean one turn? Or more. Appreciate if you could explain.
Thanks again
Rich

[Wayne M.]

Found Fan Adjust article - RESTORER Vol 17 #3

Winter 1991 isssue. Article by Henry Molatch. Shows how to adjust both the Eaton (coil) and the Sweitzer (flat bimetallic strip).

If you don't have access to this, I can scan and post, or email (send me an email so I can see your address, for attachment purposes).

For coil type lift end out of factory slot and rotate counter-clockwise (facing coil) until the end rests against the tang opposite to the slot tang. If you try to rotae in opposite direction you'll find high resistance.

Wayne