Alternator Alignment 1963 327/250HP
I've noticed that the alternator on my '63 327/250hp non-a/c vette is slightly "offset" from the fan pulley. In looking at the NCRS technical manual / judging guide, it comments that "the pulley...is offset based on the alternator application and additional options such as air conditioning". What it doesn't say is how much the offset should be. Mine appears to be about a 1/4" offset and am wondering if that seems correct? Anyone know? Thanks very much.
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Re: Alternator Alignment 1963 327/250HP
Post a picture. I have a 250hp 63 also. Show the alternator also.
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Re: Alternator Alignment 1963 327/250HP
My first time trying to post photos so, not sure I got it right but, am attempting to upload two photos of the alternator. Would like to know if the 1/4" offset between the alternator and the fan pulley is correct. BTW, I tried the belt on the other fan pulley slot and the offset is the same, just in the other direction. Thanks.
corvette 002.jpg
corvette 006.jpgComment
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Re: Alternator Alignment 1963 327/250HP
My first impression from your photos, which by the way are good, is that you may have an SHP pulley on the alternator. I just checked mine and came up with a couple of dimensions you might want to check;
alternator case front over front of pulley = 1-7/8"
pulley diameter = 3-5/8"
Mine is a L-76 340 hp which uses an additional idler pulley with a double groove water pump pulley.
Stu FoxComment
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Re: Alternator Alignment 1963 327/250HP
Joseph------
You have the wrong alternator pulley and that is your problem. You require a GM #3830422 which is a pulley and fan integral unit. It is a stamped steel type pulley. This pulley was discontinued a long time ago and, as far as I know, is not reproduced.
Addendum
I take the above back. The set-up you have may be the "correct", original installation. If so, it was a HORRIBLE design and, if it were me, I would not stick with it even if it's configuration-"correct". I'd replace the pulley with a stamped steel pulley of approximately 2-7/8" OD. These are not hard to find.In Appreciation of John HinckleyComment
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Re: Alternator Alignment 1963 327/250HP
Joe, are you sure about this? That pulley looks just like the one on my '63 327/300.
Too, it appears to my eye that the OP could achieve proper alignment if he simply moved the belt to the forward sheaves on the water pump and crank pulleys.
JimComment
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Re: Alternator Alignment 1963 327/250HP
I have been able to correct some of the alignment issues when it is only the water pump sheave that is off. One can move the hub on the water pump shaft. Their are specifications on the hub location and they are very model specific. If the bottom pulley lines up, move the top one on the w/p shaft and call it good. Beware hub is a tight fit.Last edited by Richard G.; November 6, 2010, 12:05 AM.Comment
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Re: Alternator Alignment 1963 327/250HP
I appreciate all the feedback to my question. I'll take a close-up photo of the alternator pulley in the morning and post it in this thread since there seems to be a question about whether its the right onw. Also, I did try changing the belt over to the other pulley on the water pump but then the alternator pulley seemed offset in the other direction. Thanks again.Comment
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Re: Alternator Alignment 1963 327/250HP
Jim------
You must have missed my addendum. Looks like I must have posted it while you were composoing this response. I agree that the set-up is likely the original set-up. However, as I mentioned, I think it's a very poor design.
Also, I agree that the alignment might be better if the belt were installed in the forward groove of the water pump pulley. However, Joseph mentions that when he does that he has about the same improper alignment but in the "opposite direction".
As I mentioned, I think this problem could be solved by the installation of a stamped steel type pulley of about 2-7/8" OD. I have no idea why GM didn't do this in the first place.In Appreciation of John HinckleyComment
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Re: Alternator Alignment 1963 327/250HP
Joseph,
Your pulleys W/P, crank and alternator look to be correct. The belt should be on the forward grooves on the W/P and crank.
Post some pics of the lower alternator bracket, the one that bolts to the exhaust manifold. It's possible the passenger car or A/C part lower alternator bracket could have been used there because the original broke. This will keep the alternator from being far enough forward to line to the correct groove.
A few more pics will clear it up.Comment
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Re: Alternator Alignment 1963 327/250HP
Here are a few additional photos showing a close up of the alt pulley and the mounting bracket as well as other views. Can't fit them all in this post so will do another with the remaining pics.Comment
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Re: Alternator Alignment 1963 327/250HP
Here are the remaining pics of the alt bracket. Thanks for all the feedback.Comment
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Re: Alternator Alignment 1963 327/250HP
Thanks for the feedback. I posted a few more pics. Check back to my replies and you will find them. Thanks again.Comment
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Re: Alternator Alignment 1963 327/250HP
I'm out in left field on this one. We need more input from base engine owners. My L-76 belt is in the forward groove, but then I didn't know the base engines had double grooved pulleys, rather I thought that it started with the L-75. If indeed that all the engines had the double grooves, then I agree the misaligment is with the alternator mounting, and perhaps it does have the wrong bracket.
Are you sure the belt doesn't align right in the forward groove? That is where it is supposed to be for sure.
Stu FoxComment
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Re: Alternator Alignment 1963 327/250HP
I've looked at the AIM and run out to the garage a couple of times to compare your photos with my car. I really don't see anything obviously amiss. Your lower bracket looks right, the adjustment bracket has the correct forward offset in it (???). What is the reason for the sleeve around the heater hose? Was there some interference or heat concerns there?
Stu FoxComment
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