Excessive Fan Noise due to fan speed

[RemCharger]

Mods can we please lock this thread up until all the participating members go out and purchase Decibel meters so we can speak about exact measurements?
And then all drive by members will be able to understand the conversation

 

[1 Wild R/T]

Mods can we please lock this thread up until all the participating members go out and purchase Decibel meters so we can speak about exact measurements?
And then all drive by members will be able to understand the conversation

I have a DB meter... Don't you? However... I've never needed it to decide if a fan is "Loud"...

 

[dadsbee]

As a kid I stuck my finger in the fan... it was only loud when I stuck my finger in the wrong side !!

 

[1 Wild R/T]

As a kid I stuck my finger in the fan... it was only loud when I stuck my finger in the wrong side !!

Was it loud? Or were you loud???

 

[dadsbee]

Probably evenly matched... I didn't have a DB meter at 7....

 

[1 Wild R/T]

Probably evenly matched... I didn't have a DB meter at 7....

Me either... We both lived a deprived childhood.....

 

[1967coronet]

Noise is subjective and is measured in dB or Sound is measured in decibels (dB). "It quieted down some means nothing".....how many dB .....it is determined by the listener as to its level of acceptance....some people are more/less sensitive than others.....
"A whisper is about 30 dB, normal conversation is about 60 dB, and a motorcycle engine running is about 95 dB. Noise above 70 dB over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears".
BOB RENTON

What ?

 

[eldubb440]

 

[Kern Dog]

I just couldn't do ****!

 

[68 Sport Satellite]

ok back on topic!
I've done more reading all over the web and it seems that most complaining of excessive loud fan clutch noise are using the heavy duty HD clutches. Regular duty clutches not seeing this issue for the most part. Good - so I'm not imagining this.

I'm limited on fan clutch options due to my thicker aftermarket Griffin radiator. KD has another Hayden 2947 shortie in his jigsaw charger that appears to be looser. He's going to try it in my car to compare. If that doesn't work, good Lord - I may need to swap to a thinner radiator to accommodate a longer neck fan clutch and sell off the Griffin. Good thing there are other radiator options that should also cool ok. If it's not one thing it's another!

 

[1 Wild R/T]

ok back on topic!
I've done more reading all over the web and it seems that most complaining of excessive loud fan clutch noise are using the heavy duty HD clutches. Regular duty clutches not seeing this issue for the most part. Good - so I'm not imagining this.

I'm limited on fan clutch options due to my thicker aftermarket Griffin radiator. KD has another Hayden 2947 shortie in his jigsaw charger that appears to be looser. He's going to try it in my car to compare. If that doesn't work, good Lord - I may need to swap to a thinner radiator to accommodate a longer neck fan clutch and sell off the Griffin. Good thing there are other radiator options that should also cool ok. If it's not one thing it's another!

Drive the car.... Is it just a short period of loud till the engine heats up some? Or does it continue? As I said before, my green car is loud for a few minutes... But by the time I hit the next block it's pretty normal... And as I've gotten a few miles on it the noise goes away even quicker...
Why throw money & parts at a non-issue?

 

[Ron H]

Noise is subjective and is measured in dB or Sound is measured in decibels (dB). "It quieted down some means nothing".....how many dB .....it is determined by the listener as to its level of acceptance....some people are more/less sensitive than others.....
"A whisper is about 30 dB, normal conversation is about 60 dB, and a motorcycle engine running is about 95 dB. Noise above 70 dB over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears".
BOB RENTON

Ahh yeah, sold my sound-level measuring equipment when I retired, part of my work was conducting surveys for osha compliance, engineering/sound-reduction controls when it was required, determining appropriate PPE to be worn for the exposure, initial and annual employee training, writing the mandated programs…a few hundred times.

All I mentioned was checking some reviews to see if others had complaints about noise. It didn’t mention the measured noise levels or the reduction in noise obtained…

 

[68 Sport Satellite]

Drive the car.... Is it just a short period of loud till the engine heats up some? Or does it continue? As I said before, my green car is loud for a few minutes... But by the time I hit the next block it's pretty normal... And as I've gotten a few miles on it the noise goes away even quicker...
Why throw money & parts at a non-issue?

It's not going away so it is an issue. Greg is driving it again today to go back to the A/C place and can say if it's any better.
We're not throwing money and parts at it just yet - just digging for info so we can decide what to do. And if it was a non-issue, then why are there so many numerous other reports of this same issue from others using new HD fan clutches?

By the way, in your green car are you also using the same Hayden 2947 HD shortie neck fan clutch?

 

[kiwigtx]

I get a three finger gap between the blades and shroud.

In certain situations, three fingers makes quite the difference.

The 'excessive' noise could be caused by the shape of the fan mismatched to the shroud, accessories in the path of the forced air that were not there at a factory configuration with that fan, or maybe there is a blade out of shape?

It pays to know everything is matching before swappping parts out.

My buddy Cliff had a load of trouble getting his mild (more like tame) 440 to stay cool - swapped out different fans, clutches, shrouds until he found the right combination. Granted his problem was cooling not noise, but it shows the differences.

 

[70bigblockdodge]

Always use a fan clutch. Chrysler developed these in the 1950's. The don't require as much power with a more aggressive fan. Thermal units will move toward lock up as unit gets hot, now if it's 5" away from radiator you are losing some of this action. Only cheap cars with small radiators should have direct drive.
You losing horsepower for nothing and losing fuel mileage.
Engine masters lost over 30 HP with a direct drive 7 blade fan, you can feel a 30 HP loss. Fuel mileage also. For you guys that only drive local, and less than a thousand miles a year, stop reading this and go drive your car. For those that put 4-5 k a year on. Quicky math with rounded numbers has you spending about $133 more in gas at 12 mpg and losing 1 mpg because of direct fan. That is like 2 free tanks of gas, without sounding like a noisy Chevy cretin when running through the gears.

 

[Ron H]

losing horsepower for nothing and losing fuel mileage.

Never gave this much thought, actually none, other than remembering how much heavier the 7-blade fan I installed was from the 4-blade I removed. No clutch. Maybe I should put one in...

 

[Dennis H]

 

[Ron H]

View attachment 1632518

Can’t take it anymore in general or just this thread?

 

[Dennis H]

In general, especially…

 

[Ron H]

In general, especially…

Me too..