Clutch Fan Or Not?

[dougo]

Was thinking of installing a clutch fan. It will cut down on engine noise (when it's not necessary for the fan to run) - which to be honest is my number one reason to installing it. Anyone have success, or issues with clutch fan?

[vectorit]

I plan to do this as soon as I can afford to get the fan/clutch parts, and I am doing it to get rid of the noise as well. I think it's the best thing really, and has to be more efficient than what I have now (original 4 fixed blade unit).

[DINS 1]

Have you thought about the dual electric fans They might be more quiet than the clutch fan. There are others here that have the electric fans. Just a thought.

[capev86]

my dad saved the 7 blade semi-flex fan off his 72 burb 20 years ago and i installed it on my 72 burb to replace the stock 4 blade when i upgraded to a 4 row radiator. it is a direct connection so there is no clutch to wear out and the slight flex cuts down on drag and noise at higher engine speeds. my opinion is that it will still provide plenty of cooling, especially when i have no automatic trans or a/c to put demand on the cooling system and i am running a 4 row and a 180 deg t-stat. i also run synthetic fluids in my burb and may install an aux oil cooler when i replace the 307 with a 406sbc i have in the wings.

if you tow trailers, you need to be aware that a fan may not provide enough cooling at high engine speed / low road speed to remove heat from the radiator. that is why electric fans are very popular because they respond to engine temp and operation is not dictated by engine rpm. on my truck i wanted the simplest, factory looking upgrade i could do and i had the 7 blade fan already.

[olblue60@aol.com]

I have it on my panel truck. it works great!

[dougo]

Originally Posted by DINS 1

Have you thought about the dual electric fans They might be more quiet than the clutch fan. There are others here that have the electric fans. Just a thought.

Have not thought about electric fans... thanks for the tip. I'm going to make some kind of change within next couple weeks... I've got a lot of good feedback on this - thanks guys!

[chris mc bride]

I would go with dbl electric fans if you have the cash. A clutch fan will work fine.They have been oem for years.In my opion the efect on noise wouldn't be much escept when the fans disengauged(highway speeds) ,which would have no effect when sitting still or in traffic. Be sure to have shroud for the electric fans in order to get best results. If you have a uto you can always add a temp contolled fan to the coil for it.

[dougo]

Originally Posted by chris mc bride

I would go with dbl electric fans if you have the cash. A clutch fan will work fine.They have been oem for years.In my opion the efect on noise wouldn't be much escept when the fans disengauged(highway speeds) ,which would have no effect when sitting still or in traffic. Be sure to have shroud for the electric fans in order to get best results. If you have a uto you can always add a temp contolled fan to the coil for it.

I've been thinking more about going with a double electric fan... thanks for the information. Anyone have suggestions on what set up for an electric fan?

Thanks

[chris mc bride]

check sumit catalog theres 1/2 dozen or so. I would go with the biggest you can fit into spoace. I would stagger them power wise. One come on at 160 or so and the other around 200. this way you can keep it cool and not have added drain on electrical system unless its needed. Extra benifit is the freed up powert the fans rob from the motor. Not a lot but hey it all adds up to free power that was being wasted and it doesnt hurt milage either.

[my67chevytruck]

see my posts in this thread:

http://67-72chevytrucks.com/vboard/s...diators&page=2

[dougo]

Thanks for the info, everyone - including the links!

-Doug

[Longhorn Man]

I would opt for the clutch fan. Get the thermostatic one, not the viscus or however its spelled. The thermostatic ones will spin the fan a lot slower (and quieter) untill the fan is needed then it'll kick on.
A flex fan is bad news, seen too many rip apart and rip through the hood... stock ones too. Thats why GM did a recall on flex fans in the 70's. Plus they just don't cool very well.
Electric units are an option, but have there drawbacks too. You'll need to upgrade the charging system, and I would only use the best relays and fans. I would use OEM stuff, not aftermarket units. With the electric units, you are trusting your engine to electrical contacts and electric motors, while they have come a long way in the last 20 years... I just remember doing WAY too many head gasket jobs on 80's cars when the fans would poop out. And as far as the HP increase, there's mo such thing as free lunch. The electricity has to come from somewhere, and it comes from the belt that drives the alt... just like the mechanicly driven fan would. And whenever you convert one form of energy to another form of energy, you lose efficacy. To take mechanical energy, and turn it to electrical energy, then convert it back to mechanical... there's some efficacy lost there.
The thermastaticly controlled clutches are the bast pieces for max cooling. This is why, even with the modern electrical circutry, all the HD vehicles have mechanicly driven fans that turn off when not needed and kick on when needed.

[dougo]

Originally Posted by Longhorn Man

I would opt for the clutch fan. Get the thermostatic one, not the viscus or however its spelled. The thermostatic ones will spin the fan a lot slower (and quieter) untill the fan is needed then it'll kick on.
A flex fan is bad news, seen too many rip apart and rip through the hood... stock ones too. Thats why GM did a recall on flex fans in the 70's. Plus they just don't cool very well.
Electric units are an option, but have there drawbacks too. You'll need to upgrade the charging system, and I would only use the best relays and fans. I would use OEM stuff, not aftermarket units. With the electric units, you are trusting your engine to electrical contacts and electric motors, while they have come a long way in the last 20 years... I just remember doing WAY too many head gasket jobs on 80's cars when the fans would poop out. And as far as the HP increase, there's mo such thing as free lunch. The electricity has to come from somewhere, and it comes from the belt that drives the alt... just like the mechanicly driven fan would. And whenever you convert one form of energy to another form of energy, you lose efficacy. To take mechanical energy, and turn it to electrical energy, then convert it back to mechanical... there's some efficacy lost there.
The thermastaticly controlled clutches are the bast pieces for max cooling. This is why, even with the modern electrical circutry, all the HD vehicles have mechanicly driven fans that turn off when not needed and kick on when needed.

Interesting feedback.... a buddy of mine has a clutch fan that I'm going to check out today. He's a restoration guy... so it's OEM. It's a spare that he has... said I could just have it if it fits.

After further research... I've gone back to the clutch fan. I think that's the best option for me.

Thanks Longhorn Man... that's good info to know.

[dougo]

Installed the clutch fan yesterday... I got lucky - a friend of mine had one, no need for it - and was a perfect match for what I needed (AKA - FREE). The noise level dropped significantly... BIG improvement. Between installing GM manifolds (no more headers), and now the clutch fan, I might be able to have a conversation with the kids in the third row while doing 70MPH - whereas before it was all sign language. We're going for a test ride today... and preparing for a road trip later in the week (4.5 hours one way, all highway, so it will make for a much more comfortable ride).