Alternator identification-C3

[Jeff W.]

Since everyone did such a great job solving my water pump mystery, lets solve this one. Again, I have a 1972 Convt., base 350, no AC with 56,000 miles. Build date is 7/11/72, engine build 6/28/72. The alternator is a #1100924, 2D6 (4/6/72), 55 amp. Everything that I have read shows this should be a #1100950, 42 amp. I have verification from the second owner that when bought in 1977 that this is the altenator that was on it. Everything else on the car is correct and matching.
Thanks for the help.
Jeff

[Dick W.]

Re: Alternator identification-C3

Did not come on your Corvette, but could have been installed early in life as a warranty? replacement. Do not have my Delco book handy to tell you what the application is.

[Chuck S.]

Re: Alternator identification-C3

Ah-Ha...Jeff, you don't know it yet, but you are now impaled on the horns of a dilemma!

You and Dickey are indeed correct...according to the books, the alternator part number for the 72 base engine should be 1100950. OTOH, this is a late car...Off the top of my head, I don't know the last day of production in 72, but it was in July sometime. From experience, it seems strange things can happen on very late cars when the General ran out of parts with the RIGHT number on them.

You already have some evidence that this alternator has been on the car since 1977. That says that if it's NOT the original alternator, then the original failed in the first five years of the car's life. That's possible, but based on my car still having it's original alternator after twenty-one years (1991) and at least 110K miles, I would be doubtful. The date on the alternator also works as being an original alternator. Sorry, Dickey...I have to disagree with you on this one, but my opinion won't help Jeff in judging.

So, now the dilemma...What to do, Jeff? Change the alternator to a date-matched 1100950 for the judging points?...Or, keep the 1100924 fully believeing it's absolutely the alternator that came on the car. I love NCRS.

[Michael W.]

Re: Alternator identification-C3

I read the date code of 2D6 as 2nd of April 1976, not 6th of April 1972.

BTW- glad to see you back Chuck!

[Jeff W.]

Re: Alternator identification-C3

Thanks guys. I have been told that what I should do is take the care in for judging at the local chapter and then take the list of what is wrong, add up the dollars and then decide where to go from there. It just amazing how much you need to know about these cars.
Thanks for the help.

[Chuck S.]

Re: Alternator identification-C3

Hi Mike...Whew, I thought you had blown up my theoretical musings there for a second. (Yuk,yuk)

Jeff's dating is actually correct...first character is the last digit of the year, second character is the month (D=April), and the last 1-2 characters are the date of the month.

I took a little sabbatical...but I'm back, and the resto is underway. I had to come back here and spend some time to renew my NCRS brain cells by listening to the oracles.

[Dick W.]

Re: Alternator identification-C3

Glad yer are back Chuckie. Only problem with the date code is that NO Corvette of that era used a 55 amp. Will stick with my warranty? replacement theory.

[Chuck S.]

Re: Alternator identification-C3

Just be aware that your shopping list is simply a place to start your research. You have a low mileage, original car...Before you change anything on a car that is otherwise very original, know MORE about the items on the "list" than the people who judged it at the chapter level.

Some chapter level meets may have excellent C3 expertise, but sometimes not; I once filled in as a C1 judge at a chapter meet that was short judges...let's just say it was, er...interesting. At that time, I'm sure all that was known about C1s wasn't written down in the judging manual.

Some items may be clearly changed from original. For anything that's borderline, if I could find no reason why the item could not be original after consulting all the experts and books, I would leave it alone...even it didn't meet the TIM&JG criteria (this decision WILL cost you judging points).

[Chuck S.]

Re: Alternator identification-C3

Oh,Yeah?! How about Camaros, Chevelles, Impalas?

I believe when Corvette ran out of the RIGHT part numbers, all the Chevrolet bushes got beat...(Yeah, Jake, send me 200 of them 924 alternators, would ya?! I'm in hot water here.) Corvettes phased out the 1100950 alternator after 72...You think GM purchasing might have shaved their orders a little to make sure they didn't end up with any of those dinosaurs left over after 72 MY? Food for thought.

Watch out there, Papa Smurf, yer gittin' on thin ice...you'll be buying me dinner again. (Or...Was it me that bought dinner last?)

[Jeff W.]

Re: Alternator identification-C3

Thanks again for the advice. I know now before I do anyting I will throw it out there and see what sticks.
Jeff

[Dick W.]

Re: Alternator identification-C3

Me thinks that I owe you a dinner this time. I looked fer ya at SA to buy you one. Iffen I warn't so sorry I would go down to the shop and git out the Delco book and look up the aplication for the 924. I'll do that tomorrow and post the application. Joe Lucia is out of pocket this week on his way to Carlisle so he won't post.

[Jack H.]

1100950 Alt: Std For 350 '71-75... *NM*

[Chuck S.]

OK, Now I'm Really Getting Tiresome

The question probably can't be answered by anyone, even Joe...unless he has some special insight into year-end production 1972 (It could happen; he's amazed me before).

All I'm saying is that if St. Louis ran short of alternators at the end of the year, they might impress ANY ADEQUATE GM application into service to keep the line moving until they were finished. So, the Delco book won't really show you anything surprising...unless it says it's for a FORD.

For sake of argument, let's say it WAS a warranty replacement...Why would they use a 1100924 alternator if it's not a Corvette alternator? (We may be able to agree on this...it doesn't appear to be a Corvette alternator.) It seems unlikely the correct 1100950 alternator WOULD NOT be available as new service parts five years afterwards; even if it was discontinued as a production part.

Western Auto rebuild? You know the odds on getting a correct date buying rebuilds. Eh??!!!...What say you now? It's the original alternator, Dickey...it would have been easier for it to be a 1100950 non-original alternator than an original 1100924. The Corvette fathers borrowed it from another Chevy line...believe it! Check your Delco book just to see which one.

I'ma gonna git thet dinner from ya, Pappy...but, I reckon I'm going to have to make a regional somewhere to git it. Sorry I missed you at San Antonio...but, I thought about ya though.

[Chuck S.]

Re: 1100950 Alt: Std For 350 '71-75...

Yep, you're right...I should have read my spec book closer; 1100950 continued in production through 1975.

This fact doesn't change my argument; only makes it more strange that a 1100950 alternator wouldn't be available for a warranty replacement.

[Joseph K.]

Re: 1100950 Alt: Std For 350 '71-75... *NM*