1972 big block Nova
Hey I wanted to change my fan to a fan clutch and elliminate my flex fan.
I was wondering what all is involved? I have a long pump and my alternator is on the passenger side. I think I need a short pump and the matching pulleys. It looks like it will be a tight fit even then. Anyone have any pictures that would help me?

They used a thermal controlled viscous hub clutch fan on long pumps as well. No need to convert over to a short pump system. Just be sure it is a thermal control and just a fluid coupling to minimize power lose.

Here is a short pump version but it shows that the thermal hub is inside the thickness of the fan blade. The long pump hub has a shorter shaft.

http://i45.photobucket.com/albums/f63/3454545/PCCARSHOW021.jpg

Big Dave

So I still don't understand what kind of clutch I need.

You can run the same fan clutch set up that big block chevelles used, especially the LS6 454.

Take a look at this site as it explains the differences in fan clutches and the various models used by the major car and truck manufactures as OEM (stock parts).

http://www.haydenauto.com/products/fan-clutches-and-fan-blades.htm

Big Dave

Changing the fan to a clutch fan set up is not that difficult. You probably will not need to modify anything. Since the LS6 454 Chevelles came with a sever duty clutch i would reccomend that type. The correct fan and clutch assembely isnt as cheap as a flex fan:noway:.

the only items i'd think you'd need are the fan clutch and the fan clutch fan. and i wholeheartily agree... the "Thermal" or "Severe Duty" unit's the way to go ;)

i'd not recommend the "Non-Thermal" unit ;)

I have tried a clutch from a truck and it hits the radiator so I don't know if they make shorter ones or not.

They do make different length shaft fan clutches for different bodies and different length water pumps.

Big Dave

if you have the proper radiator (mounted in factory location) then i believe the Auto Part counterperson would just look up a 3rd Genner application with a BBC ;)

the fan with proper blade count and diameter should be no biggie. the fan clutch as Dave mentioned is avalable in different lengths depending on applications. the water pump shaft size i believe is 5/8" on that car so just make sure shaft size is correct and then check clutch length... they "should" be able to just look it up in their catalog...

http://www.autozone.com/R,146482/vehicleId,1734007/initialAction,partProductDetail/store,2839/partType,00118/shopping/partProductDetail.htm


here's a listing for a '69 Nova with a BBC... probably fit just fine...

I have never seen a clutch fan installed with the long water pump in a 3rd gen BB Nova....even with a 3 core radiator it has to be tight. If someone has a picture of one installed please post it....

wilma