CLUTCH FAN -- ROAR!! (Quieter options?)
 

'68 BB, original clutch fan & shroud.
I'm really tired of the incredible R-O-A-R-R-R-R every time the fan engages. Tooling through town, I'd love to just hear the exhaust, but instead it sounds like I've got a Cessna under my hood waiting for clearance to take off.
Options? Are there quieter alternatives that still provide adequate cooling?
Thanks-

I have a 76 L-48. I replaced my fan clutch last year. The old one was not really locking up at speed. With the new on it did roar.

I have since put on about 1000 miles and it seems quieter now. It does stay cooler in hot weather too.

I've never heard a stock fan and clutch do that unless the engine was seriously close to overheating. Your car might be trying to tell you something.

I put a new fan clutch on several years ago and it also roared when compared to the original one. I've since sold the car but I don't think it was a Delco unit. What brand did you install? If it's not a Delco, you might try one if they're still available.

Some are adjustable.

If you, or someone in the past replaced the clutch with a 'severe duty' clutch, it might sound like that. My clutch failed a few years ago, and I went to the parts store and that was all they had, so I put it on. I was afraid my fan was going to fly apart.

Also, it hasn't failed and locked up, has it? When the car is cold, how well does the fan spin?

more on the roar
 

No, I do not believe the car is anywhere near overheating, judging by how it's running, when this occurs, the temp gauge readings, and the fact there's not coolant loss out the overflow hose (no coolant reclaim tank on '68).

Fan spins freely, and it's not locked up. The roar is not continual. Prior to warm-up, no roar. Only after some miles and when I've slowed down to city speeds. Even then, after a while it will cut out and get quiet again. But when it's doing it's job, wow... it sounds like a swamp boat. I keep thinking... really?... do we need all this drama?

Mainly wondering if anyone's changed over to electric and found that to be quieter?

Thanks for the feedback-

I hate sounding like an airplane when I first start the car and when the clutch activates driving around. I'm going with and electric fan eventually.

My old one would spin whether the engine was hot or cold. I think it is supposed to almost lock when really hot. My new one locks when hot but is easier to turn when cool. It is the heavy duty clutch.

I would say that your thermostatic fan clutch and fan are doing exactly what the GM engineers wanted them to do.....come ON when it gets hot and turn OFF when it cools down. When the engine is fully warmed up [and on a warm/hot day], that fan will 'come & go' in city traffic. And, that 'roar' means that it's actually working and pulling more air through the radiator. :D

I have the same issue. Changed the clutch and no difference. No it is not overheating, I checked with my infrared from thermostat to radiator and back and everywhere else.

Hot or cold all I hear is fan. It does spin with slight resistance, and spins after shut off a turn or so.

I'm thinking it's costing me hp and fuel mileage as well, even though I get 17 mpg or so. My 81 has the electrics as well, they never come on ever unless I trick the switch.

I'd like to remove the fan, and rely on the electrics like newer cars do and monitor the temps.

Anyone try this?

The fan clutch should allow the fan to "freewheel" when the engine is cold, and lock up and drive the fan when the engine gets hot. It has a controlling thermostat on the front that is exposed to the hot air coming off the radiator.
The fan clutch might need a new one if it is locked up all the time.

Before you install an electric fan try to see if someome has the same unit installed so that you can hear how loud it is before you go to all the time and money. Most electric set ups are noisey when running .
It's not the fan you hear its the air that it is pushing , and that is a good thing !
A lot of electric fans are installed as a booster for stop and go traffic ,
and just use a manuel switch . I would install a coolant temp switch for myself just to make it idiot proof . :crazy2:

Bill

Just in case someone thinks that they will get FREE cooling with electric fans...

You must realize that the electric fans take energy to run, also. They require electrical power, instead of mechanical power. But, the amount of electrical power will be about the same as what the mechanical fan requires; it's just that the alternator will be doing more work converting that extra mechanical energy into electricity...so that the new fans can do the same job as the old one.

And, I also think that the electric fans are as noisy [or more noisy] as the original {when the thermostatic fan is engaged}.

Sorry....no "free lunch" with the fancy fans. :(

If it's making more noise than it used to, make sure the fan itself hasn't been damaged causing the excessive noise. Is it 5 blade or 7?

My 7 blade clutch and fan are usually very quiet, or maybe I just can't hear it over the side pipes.

Time to replace the clutch. It's 40+ years old and original, but it won't live forever.

If originality is a genuine concern, your clutch can be rebuilt.

The stock replacement fan and clutch on my 68 small block is much, much quieter than the flex fan I inherited from the PO at time of purchase.

:thumbs:

I agree. I have the stock clutch and 7 blade and in 90 plus degrees it stays quiet while keeping the engine temparature at reasonable levels (200-205F) in non-highway driving. I haven't seen a reason to change.

What kind of amp draw are the twin electrics?