Radiator Fan - overheating

[idoc]

I seem to have a small problem with overheating, more when at idle than when moving so I was wondering if there is any difference in radiator fans. I have a fan with 5 fins on right now.

While I was going through my extra parts I found a fan that had 7 fins. Would this pull any more air through the radiator. I also have another 5 fin fan that has plastic fins. The plastic fins are much longer than the metal ones on the other two.

I have also seen that a few people have replaced the clutch and it has helped. Is there any way to tell if the clutch is bad?

Thanks

[ June 02, 2003, 12:26 PM: Message edited by: idoc ]

[Don S]

..

idoc...
... If you are still going to Ouray you do need to fix the Low speed over heating problem.
... A thermal fan clutch, with spring in the center of the fan clutch, in GOOD condition will spin easy when the clutch is cold and it will be more difficult to spin when it is hot. First spin the fan by hand when the engine is cold. Step #2 Start engine and let it warm up to normal temperature and get the clutch hot then turn the engine off and carefully spin the fan by hand and if it is OK it will be a bit harder to spin.

... OR when the engine is good and hot open the hood, with engine running, turn off key, watch fan, it should only turn about 1 revolution before stopping completely, and will be good hint as to whether the clutch is working properly. Flex fans lose blades more often than stock and use more power the ones with a clutch.
MORE INFO
LINK> OVERHEATING (http://groups.msn.com/ATexasOklahomaJeepClub/ouraycotopic.msnw)

Good Luck.. http://www.boylover.net/ubb/graemlins/cool_shades.gifand CUL.. Don S.. IFSJA.ORG

[AMX factor]

Get a fan shroud also. Helps immensely with overheating. Also use the 7 blade and do as Don S sez and get a clutch fan.

[idoc]

Well, I got looking into things and come to find out there is no clutch on my fan. The PO had installed a spacer and that is all. I now need to put my front clip back on and measure the distance from the water pump to the radiator to make sure I have room to install a fan clutch.

I will also be replacing the 5 blade fan with the 7 blade fan and I also have a fan shroud that I will be installing.

Any other suggestions while I have things ripped apart?

[Don S]

..
idoc...
... The fan clutch is only installed to reduce power consumption by the fan. The fan without the clutch will draw more air. The shroud is very important for low speed cooling. Inspect the seven blade fan for cracks and try it.

Good Luck.. http://www.boylover.net/ubb/graemlins/cool_shades.gifand CUL.. Don S..

[ June 02, 2003, 09:07 PM: Message edited by: Don S ]

[AMC258]

If nothing else, install an electric unit on the outside, toggle on the dash, and you'll have more airflow, without sacraficing mileage or power.

[will e]

The shroud will be a big help. Without it the fan doesn't draw nearly as much air when you are not moving.

[Tad]

David, is this on the '66?
I run no fan shroud, 180 thermostat, and stay at 180 all the time (freeway, in town, out of town) on the buick 350.
Buick 350/TH400/clutch fan at about 67K.
I think the answer here is the key components, once everything is doing it's job correctly, you will be fine.
If you do try a shroud from a AMC 360, and it fits the Buick 350, please let us know, we have been waiting a long time for that info.