Questions about Fan Clutch

[Isaiah92260]

I was reading threw forums and online, and realized I've never thought about my fan clutch, or do I even have one? I don't know too much about them and I'm hoping if someone could explain what do they do and what are they for? And if I possibly should replace mine? I have a 67' I6 250, 4.1L, with a aluminum Radiator that sits 1 inch from the fan, I don't have a fan shroud yet, but I am going to by a universal one this week from EBay, does anyone think that I should get one? Maybe I over looked it, my truck sitting at idle can go from 190 to 210, and I've seen it go to 230 and I got scared and shut it off, this was a month ago when it happened, but it was 115 outside that day in the desert.

[Jurassic-1]

A fan clutch is a large round unit bolted to the water pump and the fan has a large bolt pattern and bolts to the clutch. It is designed to save fuel by fee wheeling when the engine is cool and as the temp rises a spring on the front of the clutch tightens and engages the fan. It is also much quieter when running compared to a stock fixed fan. I run one with a 5 blade fan on my 66. I have a 250 engine and the temp stays just above 1/4.

[TJ's Chevy]

Convert to an electric fan. Preferably a 16 inch puller rated at Least at 2000 cfm. Hook it to a manual switch so you can turn it on and Leave it on. Then you'll have full cooling power with the engine idling or not. Also a slightly smaller water pump pulley with help flow things a bit better.

[Isaiah92260]

Originally Posted by TJ's Chevy

Convert to an electric fan. Preferably a 16 inch puller rated at Least at 2000 cfm. Hook it to a manual switch so you can turn it on and Leave it on. Then you'll have full cooling power with the engine idling or not. Also a slightly smaller water pump pulley with help flow things a bit better.

That sounds like a great ide! I was thinking about adding a universal fan shroud and hook up a manual switch Pusher fan, how do I hook up a fan to my truck with out going straight to the battery? I don't want to kill my battery every time I switch it on, do I just hook it up to my Horn Relay?

[TJ's Chevy]

Originally Posted by Isaiah92260

That sounds like a great ide! I was thinking about adding a universal fan shroud and hook up a manual switch Pusher fan, how do I hook up a fan to my truck with out going straight to the battery? I don't want to kill my battery every time I switch it on, do I just hook it up to my Horn Relay?

Well here's how we did it on my Dad's truck. 77 chevy with a BB496. Duramax diesel radiator and dual 14 inch puller fans with a shroud. We did a direct 12 volts from the battery to the switch and from the switch to the fans. Two switches for us since we have two fans. But since you'll only have one a single 14 gauge wire from the battery to a fairly high amp switch...I'd say 30 amp min so its heavy duty....due plan on putting an inline fuse in between the battery and switch...and run the same 14 gauge wire to the fan....the fan will also have a ground which can be mounted on bare metal in a good place. You Will have limited room from the nose of the water pump pulley to the fan so I'd be careful about getting a shroud that puts the fan to far out...I'd try it without a shroud...then go from there. An electric fan even without a shroud will make improvement over a manual fan especially if its pulling and pushing some air.

[Isaiah92260]

Originally Posted by TJ's Chevy

Well here's how we did it on my Dad's truck. 77 chevy with a BB496. Duramax diesel radiator and dual 14 inch puller fans with a shroud. We did a direct 12 volts from the battery to the switch and from the switch to the fans. Two switches for us since we have two fans. But since you'll only have one a single 14 gauge wire from the battery to a fairly high amp switch...I'd say 30 amp min so its heavy duty....due plan on putting an inline fuse in between the battery and switch...and run the same 14 gauge wire to the fan....the fan will also have a ground which can be mounted on bare metal in a good place. You Will have limited room from the nose of the water pump pulley to the fan so I'd be careful about getting a shroud that puts the fan to far out...I'd try it without a shroud...then go from there. An electric fan even without a shroud will make improvement over a manual fan especially if its pulling and pushing some air.

That sounds awesome, what kind of fuse should I put I between the the fan and switch? A 30amp?