Installing a fan clutch?

by 76malibu Sat Mar 19, 2016 10:10 pm

I started my Malibu today as part of my winter maintenance drill. Then I understood the annoying airplane-line sound I hear all the time comes from the fan.
I made some researches and found the wonderful world of cooling systems ... as far as my understanding goes, I think I'll upgrade my "direct-drive" fan (as seen on the pic below) for a thermostatic clutch like that:
http://www.rockauto.com/en/moreinfo.php?pk=1793434&cc=1054808&jsn=407

I live in Canada and plan on using the car on Sundays so I think a clutch upgrade will allow to:
- warm up quicker
- be less noisy
- get eventually more fuel economy

The engine is a 1976 stock Chevy 350 2bbl, no A/C.

Am I missing something or the upgrade looks safe for you?
Thanks
Installing a fan clutch? Img_2012

by Mcarlo77 Sat Mar 19, 2016 11:25 pm

I thought all our cars came with a thermostatic fan clutch from the factory? I know both my cars have them.

Speaking of noise...I remember years ago I replaced the fan clutch on my Ford Exploder with a Heavy Duty one. That thing wound up like an airplane after pulling out from a stop no matter what...lol! Very annoying...

by Joe73 Sun Mar 20, 2016 9:24 am

I think non a/c cars didnt come with the clutch. My 3, 73's non a/c didnt have them. But my other 6 a/c 73's did.

You will be very happy with a Hayden 2747 clutch and a stock GM 7 blade fan. The 2747 is their heavy duty unit. They make a stock replacement and and a severe duty. The severe duty will be real noisy and the stock is just that, stock.

Just fyi. These stats flow more than stock stats and are highly rated. Auto zone 15356 160 degree. And Auto zone 15358 180 degree. I'd recommend the 180 degree.

And make sure you timing is cranked up high with no detonation. The higher the timing the cooler it will run.

by 76malibu Sun Mar 20, 2016 2:54 pm

Joe73 wrote:You will be very happy with a Hayden 2747 clutch and a stock GM 7 blade fan. The 2747 is their heavy duty unit. They make a stock replacement and and a severe duty. The severe duty will be real noisy and the stock is just that, stock.

Just fyi. These stats flow more than stock stats and are highly rated. Auto zone 15356 160 degree. And Auto zone 15358 180 degree. I'd recommend the 180 degree.

Thanks Joe. That will be the next upgrade just after installing the cooling temp gauge.

Joe73 wrote:And make sure you timing is cranked up high with no detonation. The higher the timing the cooler it will run.

I have not messed with the ignition timing yet. It's my first carbureted car so I need videos like this to educate myself:

I think the carburetor has to be serviced. I mean disassembled, cleaned, reassembled with new joints. There is a strong smell of gasoline from the engine compartment (with no leak) in the garage after each drive, so I hope a good cleaning and tune-up will solve this problem.

At this point I may install a Holley 4160 instead (with an Edelbrock EPS intake manifold).
I also plan to install a Wideband Air/Fuel ratio sensor to ease the tune-up:
http://www.amazon.com/Innovate-Motorsports-MTX-L-Wideband-Ratio/dp/B004MDT8MW/ref=sr_1_1?ie=UTF8&qid=1458498616&sr=8-1&keywords=innovative+3844

Then 800$ and 4 months later it will be time to change the suspension components Very Happy

by dynchel Sun Mar 20, 2016 4:02 pm

My '74 (non a/c) didn't have a fan clutch either. Joe is probably right with the a/c assumption. Mine also has manual brakes (no booster). People always comment on that.

by 76malibu Sun Mar 20, 2016 7:27 pm

76malibu wrote:There is a strong smell of gasoline from the engine compartment (with no leak) in the garage after each drive, so I hope a good cleaning and tune-up will solve this problem.

Ahah, I just found what it is. A carburetor cleanup will certainly not fix that broken fuel line! Very Happy

How can I miss that! Maybe the leak was not as severe last year.
Installing a fan clutch? Img_2013

by bracketchev1221 Mon Mar 21, 2016 8:15 am

I did the same on my 76. It would eat fan belts like crazy. The thing would squeal and then they put new belts on it before I got it. I measured the shroud opening and bought a clutch and fan setup from summit. Never had a problem with overheating or anything.

by 76malibu Mon Mar 21, 2016 1:09 pm

bracketchev1221 wrote:I measured the shroud opening and bought a clutch and fan setup from summit. Never had a problem with overheating or anything.

Do you have the model name or part number in your files?

The following guide talks about standard duty vs heavy duty clutches:
http://www.rockauto.com/genImages/93/haydenSD-HD-SVRD.pdf

So if I am not mistaken, if the fan has 2-1/2 of pitch I MUST use a heavy duty clutch.

by bracketchev1221 Mon Mar 21, 2016 1:31 pm

http://www.summitracing.com/parts/flx-5718/overview/

It was like this. I forget what the diameter was based on the opening.
And the clutch was just one of these.

http://www.summitracing.com/parts/hda-2705/overview/year/1976/make/chevrolet/model/malibu

by BBMALIBU Tue Mar 22, 2016 12:15 pm

76malibu wrote:

So if I am not mistaken, if the fan has 2-1/2 of pitch I MUST use a heavy duty clutch.

Yes...or the severe duty per the Hayden website.

by dynchel Wed Mar 23, 2016 9:17 pm

You could always upgrade to electric fans. You would need a 100 amp alternator, but they clean up the engine compartment and are supposed to be worth a few h/P. I've heard up to 10

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