Non-electric Quieter Fan Options - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bearhawg · 10-22-2018, 09:42 AM

As everyone knows the standard factory cooling fan sounds like a jet at take off. WITH OUT going electric is there a quieter option? No over heating or other cooling issues, just wondering.

Thanks!

**tdangle** · 10-22-2018, 09:56 AM

I don't think so. the noise pretty much corresponds to the amount of air flow. Hard to get one without the other. The quietest setup is probably a 7 blade fan on a thermo clutch assembly.

Bearhawg · 10-22-2018, 01:56 PM

Thanks. I assumed there was no silver bullet but you never know.

**HO455** · 10-23-2018, 04:29 PM

Quote:

Originally Posted by tdangle

I don't think so. the noise pretty much corresponds to the amount of air flow. Hard to get one without the other. The quietest setup is probably a 7 blade fan on a thermo clutch assembly.

This has my vote too. I drove my Burban to work most of the summer and never heard the fan and the truck never got even warm. Best of both worlds. I can hear the fuel pressure regulator working and it is mounted on a fender well. What I'm trying to say it is pretty quiet inside and I'm sure I would have heard the fan.

**jeffahart** · 10-23-2018, 06:44 PM

Are you sure you don't have a flex fan? They are noisier than a jet, more dangerous too. Like said, proper fan and clutch, and proper shroud will be smooth and peaceful.

j

**Stocker** · 10-23-2018, 08:27 PM

Quote:

Originally Posted by tdangle

The quietest setup is probably a 7 blade fan on a thermo clutch assembly.

Agreed 100%. I wouldn't trade mine for anything.

ZEKE68 · 10-23-2018, 11:07 PM

Engine driven clutch style fans are alot quieter than non clutch direct drive fans.

Bearhawg · 10-24-2018, 07:59 AM

Quote:

Originally Posted by jeffahart

Are you sure you don't have a flex fan? They are noisier than a jet, more dangerous too. Like said, proper fan and clutch, and proper shroud will be smooth and peaceful.

j

I could not swear it is not a flex fan but from the look of it appears to be original and there is a clutch in place. The shroud is in place as well. I do notice that the fan noise does not start until a few seconds after the engine is started. Almost like it is spinning up to speed. I've pretty much decided that everything is normal and I'm just over thinking this.

Thanks to everyone for their input. I always appreciate the willingness of members to help out a rookie.

**Stocker** · 10-24-2018, 08:50 AM

You might have a non-thermal fan clutch.... or a defective clutch that is locking up too soon. Pics would help us figure out exactly what's on there.

davepl · 10-24-2018, 09:46 AM

Not so sure we all agree on what we all know, because I've got the giant factory AC 7-blade monster and shroud (and every factory piece) and it's honestlty pretty darned quiet. Maybe you've got a locked up clutch or a fixed fan?

Bearhawg · 10-24-2018, 12:25 PM

Quote:

Originally Posted by Stocker

You might have a non-thermal fan clutch.... or a defective clutch that is locking up too soon. Pics would help us figure out exactly what's on there.

Thanks! I'll take a few pix and post them this afternoon.

Bearhawg · 10-24-2018, 07:56 PM

I wasnt sure what views would help so I took a few without completely removing the shroud. the fan turns but not freely. Im almost positive it is a stock fan.

**HO455** · 10-24-2018, 09:44 PM

Yup it looks like mine. If I was to guess I would say the clutch is causing the fan to spin faster than needed thus making it noisier than it should be.

RustyBucket · 10-24-2018, 10:05 PM

If that clutch is working properly the fan shouldn't make much noise. How does it feel if you turn the blade? I have 7 blade clutch fans on both my trucks. My hearing's not great but I do hear a lot other old truck noises(lifters, A/C compressor....) over the fan. That's standing in front with the hood up. Driving I hear road noise, wind, exhaust, but not the fan.

**Stocker** · 10-24-2018, 10:42 PM

First off, it sounds as though your clutch may be working properly -- that is, it turns but not too freely. It should feel like it's operating in molasses. Your fan does appear to be stock, but is it a 6-blade or 7-blade fan? I don't know how much noise a 6-blade makes, but my 18" OEM 7-blade is very quiet, barely audible, when the clutch engages. My truck has a fairly new Hayden #2747 fan clutch.

You have a thermal fan clutch (good) but it's a standard duty (smooth face with fins only around the outer edge) and you might be better off with a heavy duty. See all the extra fins across the face of HO455's clutch? That's an indicator of a heavy duty clutch. Good info on Hayden's website https://www.haydenauto.com/featured%...s/content.aspx. Basically, use a standard duty if your fan blades have a 1 1/2" pitch. Heavy duty should be used with 2 1/2" pitch fans, which is what yours appears to be.

While a heavy duty clutch might help with engine cooling (you have not mentioned any problem with cooling / overheating), I don't think it would make your fan any quieter. So it might be info you didn't ask for and don't need!

**jeffahart** · 10-25-2018, 12:18 AM

Hmmm, are you sure the fan is the source of your noise issue? Lots of stuff near the fan that can scream under load. Power steering, AC compressor, water pump, metal on flywheel cover rubbing, the list just goes on. Just saying. Maybe a bit of throttling with the fan unhooked. Get your stethoscope down there. I am now skeptical it's your fan.

j

10-22-2018, 09:42 AM	#1
Bearhawg Registered User Join Date: Feb 2018 Location: Snellville GA Posts: 104	Non-electric Quieter Fan Options As everyone knows the standard factory cooling fan sounds like a jet at take off. WITH OUT going electric is there a quieter option? No over heating or other cooling issues, just wondering. Thanks!

10-22-2018, 01:56 PM	#3
Bearhawg Registered User Join Date: Feb 2018 Location: Snellville GA Posts: 104	Re: Non-electric Quieter Fan Options Thanks. I assumed there was no silver bullet but you never know.

10-23-2018, 06:44 PM	#5
jeffahart Senior Member Join Date: May 2012 Location: Scottsdale, AZ Posts: 1,881	Re: Non-electric Quieter Fan Options Are you sure you don't have a flex fan? They are noisier than a jet, more dangerous too. Like said, proper fan and clutch, and proper shroud will be smooth and peaceful. j __________________ White K20

10-23-2018, 11:07 PM	#7
ZEKE68 Registered User Join Date: Jul 2012 Location: Space Coast, Florida Posts: 403	Re: Non-electric Quieter Fan Options Engine driven clutch style fans are alot quieter than non clutch direct drive fans. __________________ 1968 SWB Step Side, Big Block, 4L80E , Running!

10-24-2018, 08:50 AM	#9
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,497	Re: Non-electric Quieter Fan Options You might have a non-thermal fan clutch.... or a defective clutch that is locking up too soon. Pics would help us figure out exactly what's on there. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

10-22-2018, 09:56 AM	#2
tdangle Senior Member Join Date: Mar 2005 Location: Jurupa Valley, Ca Posts: 1,209	Re: Non-electric Quieter Fan Options I don't think so. the noise pretty much corresponds to the amount of air flow. Hard to get one without the other. The quietest setup is probably a 7 blade fan on a thermo clutch assembly. __________________ Terry 1970 Custom Camper/C20 , GM Crate 350/7004R, Dana 60, factory AC

10-24-2018, 09:46 AM	#10
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Non-electric Quieter Fan Options Not so sure we all agree on what we all know, because I've got the giant factory AC 7-blade monster and shroud (and every factory piece) and it's honestlty pretty darned quiet. Maybe you've got a locked up clutch or a fixed fan? __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

10-24-2018, 07:56 PM	#12
Bearhawg Registered User Join Date: Feb 2018 Location: Snellville GA Posts: 104	Re: Non-electric Quieter Fan Options I wasnt sure what views would help so I took a few without completely removing the shroud. the fan turns but not freely. Im almost positive it is a stock fan. Attached Images

10-24-2018, 09:44 PM	#13
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 10,803	Re: Non-electric Quieter Fan Options Yup it looks like mine. If I was to guess I would say the clutch is causing the fan to spin faster than needed thus making it noisier than it should be. Attached Images __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F2 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

10-24-2018, 10:05 PM	#14
RustyBucket Registered User Join Date: Jul 2009 Location: Space Coast, Fl. Posts: 1,050	Re: Non-electric Quieter Fan Options If that clutch is working properly the fan shouldn't make much noise. How does it feel if you turn the blade? I have 7 blade clutch fans on both my trucks. My hearing's not great but I do hear a lot other old truck noises(lifters, A/C compressor....) over the fan. That's standing in front with the hood up. Driving I hear road noise, wind, exhaust, but not the fan. __________________ Dad always said, "Son, WISH IN ONE HAND, and ......." -------------------------------------- -------------------------------------- Current toy trucks: '71 GMC 1500 SUPER CUSTOM short/step, orig. dk. blue, 350/700r, ps,pb, A/C '72 Blazer 2wd, ochre & white, 454, tremecTKO 500 5spd. ps, pb, A/C, tilt Last 10yrs of hobby vehicles, had a FEW more in the 50yrs. before these: '66 Plymouth Belvedere City of Miami cop car clone. '70 Nova 406"sb, 13.5-1, solid roller, Brodix, p.glide/t.brake, back halved, 9" Ford, spool 4.88, cage,ladder bar/coilover, 10.5 tire....... SOLD!! '67 C10 short/step side mount spare -- SOLD!! '72 Jimmy 2wd, 350/350, ps, pb, fun driver, lots of bondo & a shiny red paint job..... SOLD!! '69 Nova 350, 4spd, A/C, ps, p.b, ...SOLD!!

10-24-2018, 10:42 PM	#15
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,497	Re: Non-electric Quieter Fan Options First off, it sounds as though your clutch may be working properly -- that is, it turns but not too freely. It should feel like it's operating in molasses. Your fan does appear to be stock, but is it a 6-blade or 7-blade fan? I don't know how much noise a 6-blade makes, but my 18" OEM 7-blade is very quiet, barely audible, when the clutch engages. My truck has a fairly new Hayden #2747 fan clutch. You have a thermal fan clutch (good) but it's a standard duty (smooth face with fins only around the outer edge) and you might be better off with a heavy duty. See all the extra fins across the face of HO455's clutch? That's an indicator of a heavy duty clutch. Good info on Hayden's website https://www.haydenauto.com/featured%...s/content.aspx. Basically, use a standard duty if your fan blades have a 1 1/2" pitch. Heavy duty should be used with 2 1/2" pitch fans, which is what yours appears to be. While a heavy duty clutch might help with engine cooling (you have not mentioned any problem with cooling / overheating), I don't think it would make your fan any quieter. So it might be info you didn't ask for and don't need! __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 10-24-2018 at 11:33 PM.

10-25-2018, 12:18 AM	#16
jeffahart Senior Member Join Date: May 2012 Location: Scottsdale, AZ Posts: 1,881	Re: Non-electric Quieter Fan Options Hmmm, are you sure the fan is the source of your noise issue? Lots of stuff near the fan that can scream under load. Power steering, AC compressor, water pump, metal on flywheel cover rubbing, the list just goes on. Just saying. Maybe a bit of throttling with the fan unhooked. Get your stethoscope down there. I am now skeptical it's your fan. j __________________ White K20



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