GM alternator fans - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-15-2009, 08:12 PM
kleen56's Avatar
Registered User
 
Last photo:
Join Date: Oct 2006
Location: Santa Clarita CA
Posts: 802
Wiki Edits: 0

Thanks: 4
Thanked 6 Times in 6 Posts
GM alternator fans

I'm running a 10SI alternator on my vehicle which is running hot during the hot weather days. Does anyone know if the larger cooling fan on the 12SI model alternator is interchangable with the 10SI for additional cooling?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-16-2009, 06:47 AM
302 Z28's Avatar  
Last photo:
Join Date: May 2003
Location: North Texas
Posts: 10,837
Wiki Edits: 0

Thanks: 1
Thanked 86 Times in 73 Posts
How do you know your alternator is running hot?

Vince
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-16-2009, 09:33 AM
kleen56's Avatar
Registered User
 
Last photo:
Join Date: Oct 2006
Location: Santa Clarita CA
Posts: 802
Wiki Edits: 0

Thanks: 4
Thanked 6 Times in 6 Posts
Vince, we've been having 100+ temps here in CA. Whenever I go out to a show or cruise in the high temps, after a while of driving, the alternator will shut down and stop charging until it cools. I spoke to a few buddies who have the same problem with the 10SI type alternators. I guess they are notorious for overheating and thats why the improvement with cooling fans came about with the 12SI model. I also have the alternator mounted near the passenger side head and exhaust headers which doesn't help with overheating the alternator either. I should probably mount the alternator higher up above the intake, I just don't like the looks of it there. Since the 12SI alternators have little or no overheating problems, I was wondering if the fan which provides cooling would be interchangable. It would easy to do, or go with a 12SI alternator altogether. (mine is chrome and looks purdy). I also heard that overheating an alternator will kill it quickly. Trying to avoid it. I've opened my alternator several times, and everything appears to be and checks out OK. Only acts funny in really hot temps, otherwise, no problems.
Ed
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-16-2009, 12:36 PM
302 Z28's Avatar  
Last photo:
Join Date: May 2003
Location: North Texas
Posts: 10,837
Wiki Edits: 0

Thanks: 1
Thanked 86 Times in 73 Posts
I have a 10SI on my 34 and I live in North Texas we have also been having temps in the 100+ range. I have not noticed my alternator shutting down due to over heating. Of course mine is mounted above the intake manifold. Mayby you need to decrease the pulley size in order to speed the alternator up for better fan draw.

Vince
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-16-2009, 04:27 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,990
Wiki Edits: 0

Thanks: 20
Thanked 379 Times in 348 Posts
Kleen, we ran into this with the CS-140 alternator we used as an upgrade on a '67 Elky street/strip car. The alt was mounted just slightly lower (1-1/2") than the factory position in front of the pass side head. As the alt pulls air through the case from back to front(dumb idea, should be the other way around IMO), it was sucking up the hot air off the head and header tubes and dropping out until it cooled off. Our fix was to fab up a polished aluminum shield bolted to the head behind the alternator that extended out and partially back and over the front header tube at the valve cover rails height. Problem was solved.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-16-2009, 10:11 PM
kleen56's Avatar
Registered User
 
Last photo:
Join Date: Oct 2006
Location: Santa Clarita CA
Posts: 802
Wiki Edits: 0

Thanks: 4
Thanked 6 Times in 6 Posts
Quote:
Originally Posted by ericnova72
Kleen, we ran into this with the CS-140 alternator we used as an upgrade on a '67 Elky street/strip car. The alt was mounted just slightly lower (1-1/2") than the factory position in front of the pass side head. As the alt pulls air through the case from back to front(dumb idea, should be the other way around IMO), it was sucking up the hot air off the head and header tubes and dropping out until it cooled off. Our fix was to fab up a polished aluminum shield bolted to the head behind the alternator that extended out and partially back and over the front header tube at the valve cover rails height. Problem was solved.
Great info Eric. I suspected my overheating was from the engine and headers as my alternator is mounted right in that position with the back of the alternator no more than 1 inch from the engine. Anyways, just to update and maybe have some helpful info for Vince.(302 Z28). I went to a alternator rebuild place and they sold me a fan blade from a 12SI alternator for $5, it's definitely bigger and draws more air to the alternator. The fan fits right on the shaft and is inter-changeble with the 10SI alternator. I put it on, and so far so good. I hope it solve the problem with this fan blade on and it's a easy change to do, I'm opting for the plate on the heads or moving the alternator higher up and away from the heads. Thanks guys for the great info.
Ed

Last edited by kleen56; 09-16-2009 at 10:16 PM.
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
"Wiring Harness" docvette Electrical 185 10-30-2011 04:17 PM
GM 5.7L crate engine suffix codes SCRUBBY Engine 2 11-30-2009 04:36 PM
Need Wiring Diagram for GM headlight/key buzzer ChevyThunder Electrical 6 01-27-2009 02:11 PM
Important Gm "factory Freak" Cars D M N General Rodding Tech 20 11-06-2008 07:25 AM
GM 383cc Stroker build iceman36 Engine 2 03-31-2006 11:48 AM


All times are GMT -6. The time now is 12:54 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.