what size alternator - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-11-2012, 07:10 PM
billonwheels's Avatar
Registered User
 

Last journal entry: On the Road
Last photo:
Join Date: Jan 2012
Posts: 62
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
what size alternator

My buddy has a 1972 pontiac Lemans with a 400 bored 30 over. His generator light comes on while driving. Is the alternator going bad? its still a 3 wire i think. What ampreage will he need?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-11-2012, 07:31 PM
Registered User
 
Join Date: Jun 2006
Location: Indiana
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 3 Posts
I am by no means an expert but I do know that the alternator size requirement is a function of the amperage draw of the various electrical accessories on the car. That's the place to start. What's the max potential amp draw assuming likely accessories to be on at the same time?

Before looking for a higher amp alternator, I think I'd make sure the current one is doing what it's supposed to do. If your friend hasn't a clue about this stuff, then he'd probably be wise to seek some professional advice/troubleshooting.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-11-2012, 07:43 PM
66GMC's Avatar
Get in, sit down, hang on
 

Last journal entry: Cab Removal
Last photo:
Join Date: May 2005
Location: Olds, Alberta Canada
Age: 56
Posts: 2,761
Wiki Edits: 0

Thanks: 32
Thanked 90 Times in 85 Posts
According to my NAPA Prolink electronic catalog, there were 4 possible alternators on that year/make/model:


2 that were 55-63 Amp "small frame - 10SI" ... (1 with single groove, 1 with double groove pulley)
================================================== ==

There were also 2, 80 Amp "large-frame - 27SI" alternators ... again offered in single and double groove pulley versions. These alternators had a 2-leg lower mount and were an "HD option" on these cars. They were usually on the well-equipped models with AC, power seats, rear defrost, etc.

Most Delco alternators have a Delco-Remy ID number stamped into the front half of the case along with the Amp rating. It is also common practice for rebuilders to grind these numbers off of a "rebuildable core" and affix their own identification label or tag according to the rebuild specs.

IF it is still there, it will be all numeric ... something like "1101015" followed by "80A"

I can help to idenify it further if that stamping info is still available, or you can browse the
Wilson e-CAT

Note that the Wilson catalog only list 1 of each series, because their alternators are not supplied with new pullies.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-11-2012, 08:17 PM
billonwheels's Avatar
Registered User
 

Last journal entry: On the Road
Last photo:
Join Date: Jan 2012
Posts: 62
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
thanks guys, He's not running any high current audio system, just the factory stuff. He was asking me about remans and I was telling hime he couldnt wrong with an upgrade.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-11-2012, 08:30 PM
66GMC's Avatar
Get in, sit down, hang on
 

Last journal entry: Cab Removal
Last photo:
Join Date: May 2005
Location: Olds, Alberta Canada
Age: 56
Posts: 2,761
Wiki Edits: 0

Thanks: 32
Thanked 90 Times in 85 Posts
Quote:
Originally Posted by billonwheels View Post
thanks guys, He's not running any high current audio system, just the factory stuff. He was asking me about remans and I was telling hime he couldnt wrong with an upgrade.
Yes, "upgrading" from a 63 Amp to an 80 Amp wouldn't hurt anything, but he would have to have the correct mounts. Look at the two pics in my previous post ... they mount up differently.

IF he has a 63 Amp (small-frame) alternator, a shop that specializes in electrical rebuilding could overhaul it and install a "Y-wound" stator for that 80+ Amp output.
Reply With Quote Quick reply to this message

Recent Engine 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
Small Size Alternator Bad Rat Electrical 12 07-15-2010 01:20 PM
GM Alternator nut size Blazin_Jason Electrical 2 06-11-2007 07:59 PM
CS130 alternator 'size' cucumber1949 Electrical 6 12-25-2005 09:17 AM
Which size of alternator pulley?? tornado-tech Engine 5 08-07-2005 09:56 PM
Alternator Size brainsboy Electrical 1 10-21-2004 07:33 AM


All times are GMT -6. The time now is 12:49 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.