Fan Clutch Question

[Ironhorse]

Not on my '71 4x4 but my ol work car I still knock around in now being retired. '88 Chevrolet Caprice Broughm LS, 305/4BBL . Still comfortable to knock around in and can leave the Tahoe for the Mrs. to shuffle G'kids in. Currently has a 195 T'stat, cools fine with no problems there. Trouble comes from the current fan clutch that sounds like a B29 rolling down the runway prior to take off. Maybe not quite that severe but definitely noticeable. Plan on replacing it but which is preferred ......thermal or centrifugal for just a day to day driver? Easy enough to replace but not sure if was is preferred over the other now days.

[Dead Parrot]

Not sure on the thermal vs centrifugal but for a normal vehicle with no existing cooling issues, get the Standard clutch instead of the Heavy Duty or Severe Duty version.

Went down that path when I replaced the clutch on my 75 C10. Seems the default clutch the parts houses give you is the Heavy Duty version. First time at highway speed with that HD clutch, I was wondering what was wrong, there was so much noise. Went back and specified a Standard Duty clutch and things were much quieter. Have never had any cooling issues

[AcampoDave]

When I was shopping for a clutch fan for my 283 with A/C, research lead me to conclude that a centrifugal non-thermostatic unit was the more economical replacement style fan clutch. Lacking the ability to adjust for temperature makes them likely to work harder than needed in cool weather thus decreasing their ability to reduce drag. Ultimately, I spung the extra bucks for the heavy duty thermostatic unit and I can tell you it's pretty dang quiet in winter, which is nice. But, if I go out driving in triple digit temps with the A/C blasting, I can hear it roaring a bit as it does it's job. If our summers were cooler and I didn't have A/C, I would of went with a standard one. But thats just not an option around here.

[The Rocknrod]

Originally Posted by AcampoDave

When I was shopping for a clutch fan for my 283 with A/C, research lead me to conclude that a centrifugal non-thermostatic unit was the more economical replacement style fan clutch. Lacking the ability to adjust for temperature makes them likely to work harder than needed in cool weather thus decreasing their ability to reduce drag. Ultimately, I spung the extra bucks for the heavy duty thermostatic unit and I can tell you it's pretty dang quiet in winter, which is nice. But, if I go out driving in triple digit temps with the A/C blasting, I can hear it roaring a bit as it does it's job. If our summers were cooler and I didn't have A/C, I would of went with a standard one. But thats just not an option around here.

Exactly. Hayden probably makes for most situations a Super Duty, Heavy Duty and Standard Duty thermal clutch fan. They're web site you can download PDF files with specs and pics of them, you may be able to find out what clutch fan your using and adjust accordingly. Unless you do that or someone can look at it (not online) and tell you what you have, you could buy an incorrect fan clutch only to have to buy another. Or more.

[Ironhorse]

Thanks for the replies. Will check with the local parts house about a Hayden std. duty. Not sure whether will be centrifugal or thermal. See what is available and what sort of $$.

[The Rocknrod]

I went on line and downloaded they're PDF catalog/list of clutch fans. It lists specs such as water pump hub bolt pattern and water pump axle/stub diameters 5/8" or 3/4" to concern yourself with matting to your water pump. If you have a stock water pump no problem. I've seen guys buy a corvette water pump (larger axle/Stub in the center) and the clutch purchased (not corvette) wouldn't fit the hub. Just things to look out for.