Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
Ciadella InteriorsAmerican Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power Windows
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy



Username Post: Radiator fan, 327        (Topic#345974)
Flying_Dodo 
Silver Supporting Member
Posts: 19
Flying_Dodo
Reg: 07-11-17
07-11-17 05:00 PM - Post#2699675    

Hey folks, new to the forum.

Just picked up a '68 GMC.

Got a quick question, if you don't mind.

I was under the hood cleaning the idle circuit and noticed the only radiator fan is a small aftermarket electric job.

This can't possibly be enough for a 327, can it??



 
bobschevytrucks.com Ecklers

Tri5man 
Valued Contributor
Posts: 3600
Tri5man
Loc: Possums Crotch, KY
Reg: 06-26-07
07-11-17 06:05 PM - Post#2699685    
    In response to Flying_Dodo

Is it overheating? Does it run cool? What is the diameter of the "small aftermarket fan"? If it were me I wouldn't use anything but a 16 inch Spal puller fan.

Gary



 
Andy4639 
Frequent Contributor
Posts: 1108

Age: 57
Loc: Liberty, SC
Reg: 08-06-16
07-12-17 06:48 AM - Post#2699739    
    In response to Flying_Dodo

As long as it's cooling ok and not over heating it should be fine. That being said the name brand plays a big part in how long it lasts.

The cheaper fans don't last long, i have been through two on my Impala so far.



1956 Bel Air - LT-1/4l60
1964 SS Impala -350 crate/powerglide
1967 Ramp truck - 350/ 4 speed
1971 C 10 - 6.0 LS / 4l80e 4:10 gears 30 years owner
94 Elderado
2000 S-10
2008 LTZ Tahoe
2011 Treverse


 
Flying_Dodo 
Silver Supporting Member
Posts: 19
Flying_Dodo
Reg: 07-11-17
07-19-17 11:19 AM - Post#2700603    
    In response to Tri5man

Thanks.
It's hitting 215 and staying there, although I can't vouch for instrument reliability or accuracy, someone put those autozone gauges in, and while it says "water temperature", I haven't even tracked down where the sending unit is yet.
This is at idle sitting for a bit and driving 40ish MPH.



 
Andy4639 
Frequent Contributor
Posts: 1108

Age: 57
Loc: Liberty, SC
Reg: 08-06-16
07-19-17 05:04 PM - Post#2700643    
    In response to Flying_Dodo

For cooling:
Rule of thumb.

Cooling.

1,250 CFM for a 4-cylinder
2,000 CFM for a 6-cylinder
2,500 CFM for a 8-cylinder

A further note is that engines that are 5.0-liter (302 cubic inches) or larger should use an electric fan with 2,800 or more CFM. Obviously, an 800-horsepower engine will need more cooling than a 400-horsepower version regardless of the cylinder-count, but this basic guidance will get you started. And no amount of CFM will keep an engine cool if the radiator is under-sized or if too much of the grille-opening is obstructed. But let's move on, assuming that you have a typical engine in a typical enthusiast's car or 4x4 with a proper radiator.

A few rules of thumb:
Don't use an electric fan as the primary fan on 4-core radiators. It overworks the fan to try to draw air through these extremely restrictive radiators.
It's recommended to have at least 70-percent of the radiator core covered by the fan shroud.
Use puller electric fans (mounted behind the radiator) for primary cooling. A pusher (mounted in front of the radiator) is appropriate as an auxiliary fan.

These general guidelines should address most of the questions and issues you run into when trying to determine which electric fan will fit on your application.

New vehicles run at 210* all day long and are fine.



1956 Bel Air - LT-1/4l60
1964 SS Impala -350 crate/powerglide
1967 Ramp truck - 350/ 4 speed
1971 C 10 - 6.0 LS / 4l80e 4:10 gears 30 years owner
94 Elderado
2000 S-10
2008 LTZ Tahoe
2011 Treverse


 
Flying_Dodo 
Silver Supporting Member
Posts: 19
Flying_Dodo
Reg: 07-11-17
07-26-17 11:39 AM - Post#2701539    
    In response to Andy4639

Thanks. I'll keep an eye on the temps.



 
Andy4639 
Frequent Contributor
Posts: 1108

Age: 57
Loc: Liberty, SC
Reg: 08-06-16
07-26-17 05:52 PM - Post#2701577    
    In response to Flying_Dodo

You could invest in a heat gun from Harbor Frieght as well and see how it's doing.


1956 Bel Air - LT-1/4l60
1964 SS Impala -350 crate/powerglide
1967 Ramp truck - 350/ 4 speed
1971 C 10 - 6.0 LS / 4l80e 4:10 gears 30 years owner
94 Elderado
2000 S-10
2008 LTZ Tahoe
2011 Treverse


 
Flying_Dodo 
Silver Supporting Member
Posts: 19
Flying_Dodo
Reg: 07-11-17
07-27-17 04:52 AM - Post#2701615    
    In response to Andy4639

No harbour freight in this area.
It was pretty hot out yesterday (about 94), and temp gauge showed 225ish.
I'm probably going to invest in a larger cfm fan.



 
bobschevytrucks.com Ecklers

Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

772 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.709 seconds.   Total Queries: 13   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 09:15 PM
Top