Need Alternator fit advice
Thread Starter
Instructor
Joined: Sep 2005
Posts: 161
Likes: 0
Need Alternator fit advice
Hey gang,
I'm trying to order a 70 amp Alternator (Powermaster Chrome) for my '72 350. My mechanic ordered one from Summit and it came in 1-wire instead of 3 wire. I found a 70 amp chrome powermaster from Ecklers, and I of course want the chrome upper mounting brace (the long curved one) to go with it. But their description says the brace fits everything except the 70 amp, which would lead me to believe that the 70 amp would also not be a direct bolt on to the factory upper brace I have now?
Questions: I think the alternator (stock) was about 63 amps from factory, so I was trying to stay close. What issues do I have if I move UP to 85 or 100 amps? and does anyone know what makes the 70 amp unique?
And is stock an internall regulated or externally regulated alternator??
Hope these are easy questions for someone. I really don't want to pay the "corvette tax" but difficult for me to find the right alternator (generic) without additional knowledge about the right type and fit.
Thanks to all in advance!
I'm trying to order a 70 amp Alternator (Powermaster Chrome) for my '72 350. My mechanic ordered one from Summit and it came in 1-wire instead of 3 wire. I found a 70 amp chrome powermaster from Ecklers, and I of course want the chrome upper mounting brace (the long curved one) to go with it. But their description says the brace fits everything except the 70 amp, which would lead me to believe that the 70 amp would also not be a direct bolt on to the factory upper brace I have now?
Questions: I think the alternator (stock) was about 63 amps from factory, so I was trying to stay close. What issues do I have if I move UP to 85 or 100 amps? and does anyone know what makes the 70 amp unique?
And is stock an internall regulated or externally regulated alternator??
Hope these are easy questions for someone. I really don't want to pay the "corvette tax" but difficult for me to find the right alternator (generic) without additional knowledge about the right type and fit.
Thanks to all in advance!
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
There are no issue at all with upgrading to a higher output alternator. In some cases you'll want to upgrade the power wire, but other than that it's fine.
In fact, you can very easily upgrade to a more modern CS130, which is a 100 amp alternator. It's a bolt in swap, and requires only a slight modification, OR a plug adapter, to work with your car.
They are better in that they have more amps available at idle, and they are rated for more output in stock form.
In fact, you can very easily upgrade to a more modern CS130, which is a 100 amp alternator. It's a bolt in swap, and requires only a slight modification, OR a plug adapter, to work with your car.
They are better in that they have more amps available at idle, and they are rated for more output in stock form.
Burning Brakes
Joined: Sep 2005
Posts: 755
Likes: 1
From: Hobart Tasmania
If you want original/restored why not talk to Jim Price. Someone may be able to help with the email address, it is something like sheyp40@ ??????
He sold me a restored alternator and on the last NCRS chapter meet the judges comment on the judging sheets was "Best In the Show".
That's the kind of guy I like to deal with, professional in his workmanship.
He sold me a restored alternator and on the last NCRS chapter meet the judges comment on the judging sheets was "Best In the Show".
That's the kind of guy I like to deal with, professional in his workmanship.
Pro
Joined: Jul 2004
Posts: 605
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From: Alta Loma CA
I've got the 100 amp chrome Powermaster from Summit. It's a 3 wire and bolts right in. I don't have the the chrome arm but my painted arm is the long type you want. I'd go for the 100 amp, there's no substitute for more power. I have their mini starter too and both are great products.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Here is a 3 wire with brackets, pullies and water pump. All less than 500 miles.
http://forums.corvetteforum.com/show....php?t=1996355
http://forums.corvetteforum.com/show....php?t=1996355
Last edited by 63mako; Apr 20, 2008 at 05:13 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You don't get "more power" from a higher amperage alternator...you just get more capacity. If your present alternator isn't being overloaded from the stuff in your electrical system, buying a larger alternator is like paying extra money for more insurance. If you have added a hi-power stereo amp system and/or electric fans, THEN you might need an alternator upgrade.
Thread Starter
Instructor
Joined: Sep 2005
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See, that's what I thought, which is in contrast to my idiot mechanic...The alternator does not PUSH power, it provides power. When the battery is down, it provides 100watts, but once the battery is topped off, the alternator is not being called on for more juice. It doesn't overcharge the battery, right?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The alternator doesn't "overcharge" the battery, as long as the voltage regulator in the alternator is working properly. The system is self-regulating. It keeps the battery at about 12.5 vdc (turned off) and charges it at about 13.5 vdc when the engine is running. The amount of current required of it (since the voltage is 'constant', the alternator regulates the current it produces) depends on what electrical accessories are turned on when you are operating the vehicle. If the total possible current draw of your electrical system (the max current needed to run all devices on your car) is less than the max. output current of the alternator [with a little 'safety factor' thrown in], that alternator has enough 'capacity' for your electrical system. If you really do add significant load to the circuits (electric fans, big stereo amp, etc.), not only do you need to increase the size of the alternator....you also need to increase the "size" of the wire that will be carrying that additional current load.
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Thread Starter
Instructor
Joined: Sep 2005
Posts: 161
Likes: 0
Thanks, I am also now concerned a little aobut "fit" as I have aluminum finned corvette valve covers on ...wonder if the Powermaster Chrome ones that Ecklers sells are the same physical dimensions as the stock alternator? Guess I will call them Monday.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
After hearing some of the horror stories from here over the past year or so, I want nothing to do with anything bearing a Powermaster label.
I can't imagine what would be different about a 70 amp alternator, unless they're thinking of a very underpowered 12SI (though that doesn't make much sense, since Delco made 10SI alternators up to about 90 or so amps). It should just be a 10SI, and they're pretty much all the same.
I can't imagine what would be different about a 70 amp alternator, unless they're thinking of a very underpowered 12SI (though that doesn't make much sense, since Delco made 10SI alternators up to about 90 or so amps). It should just be a 10SI, and they're pretty much all the same.
Team Owner
Joined: Oct 2004
Posts: 23,831
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From: Springfield MO
St. Jude Donor '07
Does anyone other than Powermaster make chromed alternators? If that was the look I was going for, I might use one, but I'd keep an eye on it (and maybe keep a "plain-Jane" rebuilt spare in the garage for emergencies). It seems to have died down, but for a while there was a rash of Powermaster failures reported here.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
If you give me the polished housings I can guarantee a professional and new quality alternator you cant beat anywhere. But in will not be chrome. I prefer polished cases as they last longer..
Pro
Joined: Nov 2007
Posts: 741
Likes: 1
From: Woodstock GA
If you want a chrome alternator, the best way is to buy the case (or polish your own and have chromed), then take it/send it to a rebuilder. Often they can upgrade the amperage while they are at it, and build it with new or reconditioned parts. I have gone this route before, came out cheaper than an off the shelf "name brand" alternator or even a parts store rebuilt unit, and had a better alternator that I could get serviced locally if need be. Hasn't been a need so far.
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
That is what I have in the parts for sale section. Stock alternator with upgrade internals and chromed case with chrome brackets and chrome pullies, short pump setup.