Fan Clutch
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Fan Clutch
Looking for information on the fan clutch. I have my 77 Vette, was an L48 , but I have built a SBC that Mako and Billa believe will be making 400-420 HP. My fan clutch appears to be leaking, but not sure, it may be just dirt. SO I either need to get it rebuilt or buy another one.
I have bought at Dewitts aluminum radiator, Edelbrock Water Pump and want to stick with stock like thermostatic fan and stock fan shroud. With this equipment and a stronger motor, would I still want to install the same PN fan or switch to a different clutch. Also, I have heard these can be rebuilt, but really can't find anyone who does that. Finally, if buying new, any recommendations on where?
I have to admit, I really don't understand much about fan clutches.
I have bought at Dewitts aluminum radiator, Edelbrock Water Pump and want to stick with stock like thermostatic fan and stock fan shroud. With this equipment and a stronger motor, would I still want to install the same PN fan or switch to a different clutch. Also, I have heard these can be rebuilt, but really can't find anyone who does that. Finally, if buying new, any recommendations on where?
I have to admit, I really don't understand much about fan clutches.
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
The fan clutch is supposed to allow the fan to freewheel unless the engine is running very hot. Normally, you don't hear any fan noise (that is, the clutch is disengaged) unless the AC is on and it's very warm out. Very typically, if you shut off a warm engine, the fan clutch will allow the fan to spin for a couple of seconds after the engine has been shut off.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
With a DeWitt's radiator (if it is sized to handle the increased engine power), the stock thermal fan unit should work fine. Be aware that if you install a lower temp thermostat than came with the car (195*F was the stock unit), that will not change the temp at which the thermostatic fan will begin to engage. If you want the fan to come on at a lower temp, you will have to buy a different fan clutch.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I used the Hayden 2741 also. I don't have any cooling problems with the Stewart stage 2 pump, 180* ts, recored rad and oem 7 blade fan.
