Author Topic: Cooling fans  (Read 10411 times)

Offline 1979C20

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Cooling fans
« on: February 24, 2012, 10:31:03 pm »
My clutch fan is giving out, so I figured I'd upgrade. I'm looking around on craigslist for electric fans. What size fan would be sufficent to cool my truck? I found a 16in fan for 25 dollars. I figured if I were to get it and put it between my grill and the radiator and psh the air through it that it would work out pretty well. I'm just not sure if its big enough. What do you guys think?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Da67goatman

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Re: Cooling fans
« Reply #1 on: February 24, 2012, 11:24:25 pm »
I have a 16in on mine, no shroud and it worked fine, pulled a 6k lb trailer in summer heat and had no problems.  Make sure you put it on some sort of thermostat switch or you will fry the fan driving with it on.  Too much air flow spins the fan and over heats the motor causing nasty underhood fire ask me how I know. lol
<Pitcrew>
1989 R2500 Suburban mild 350 TBI 700r4 10.5" 14bolt 4.10 w/ 33s
1992 fullsize Blazer 4x4  35s no lift, 4.10s, Hella driving lights, TJ Flares, Huge bumpers, Snorkel, custom interior

Offline 1979C20

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Re: Cooling fans
« Reply #2 on: February 24, 2012, 11:27:09 pm »
okay, cool. I was planning on picking up a fan on craigslist for cheap, then going to O'reillys and getting a thermostatic control for it. Thanks for the help, Hopefully I can get a fan on it in the next week or so. Free up some ponies and some MPG buy getting rid of the clutch fan.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 1980c10

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Re: Cooling fans
« Reply #3 on: February 26, 2012, 05:30:36 pm »
I have exactly what you are describing, I bought the wiring and adjustable thermostat kit from oriellys the fan is a 16" 8 blade i bought everything new for not too much over 100. The truck has never cooled better. The best part is when people ask me how it cools without a fan and I say "I never tried it without a fan" I can post some pics if needed.


Offline Bitzer!

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Re: Cooling fans
« Reply #5 on: March 01, 2012, 04:18:14 pm »

Sorry to jump in guys, what is the diameter of the top hose where you'd insert the fan sensor?

Or is there another way you can control the fan rather than just an on/off switch?

Cheers
Andy
1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline 1979C20

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Re: Cooling fans
« Reply #6 on: March 01, 2012, 04:25:59 pm »
You would have to buy a thermostatic controller, or an Adjustable thermostatic controller. The adjustable one you can set to whichever degree you want your fans to come on and the standard is preset at a temp. You can either use a probe in the radiator, or you can thread in a temp sensor into your engine block.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Bitzer!

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Re: Cooling fans
« Reply #7 on: March 01, 2012, 05:31:16 pm »
Hi, I'm not that clever with these things. The reason I wondered about the pipe diameter is I'm looking at this!

Item number: 140568220277 It's on UK eBay if it helps!

Andy
1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline 1979C20

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Re: Cooling fans
« Reply #8 on: March 01, 2012, 08:35:33 pm »
That one should work. The radiator hose is 1.5in ID(inner diameter) which equals 38mm. I didn't know they made a thermostat sensor that goes in line with the hose. Thats pretty cool.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Bitzer!

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Re: Cooling fans
« Reply #9 on: March 02, 2012, 04:09:02 am »
I remembered these from my motorsport days, could someone do the link a little better than I can! May be easier, I'm sure you could get them over there or have it imported!!

Deffo 38mm inside diameter for the top hose??

Cheers all

Andy
1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline 1979C20

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Re: Cooling fans
« Reply #10 on: March 05, 2012, 11:46:32 am »
From what I could find online, yes you need a 38mm. But, maybe someone else can pitch in and verify?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Bitzer!

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Re: Cooling fans
« Reply #11 on: March 05, 2012, 03:33:06 pm »

Cheers fella, found a few minutes after work to cut through the hose and get the tape measure on it just to make sure!

Deffo top hose ID 38mm, fan and kit ordered.

16"fan & thermostat on way, cost around $130

Sorry for the thread hijack.

Andy
1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline 1979C20

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Re: Cooling fans
« Reply #12 on: March 05, 2012, 03:55:06 pm »
Hey, dont worry about it. It was the right subject to post under, and I didnt know about that type of thermostat so no worries.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline beastie_3

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Re: Cooling fans
« Reply #13 on: March 06, 2012, 04:17:03 pm »
I used this for my fans. I put the sending unit in the intake manifold next to the radiator hose. Just like a transmission temp gauge, you want to know what the hot fluid temp is.

http://www.summitracing.com/parts/DER-16749/

Offline Bitzer!

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Re: Cooling fans
« Reply #14 on: March 07, 2012, 03:48:52 pm »

Cheers Beastie,
All I wanted was was an easy install to fire up the fan. I didn't want to wire it permenantly or off a switch in the cab, I'd forget to turn it on!

Andy
1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*