Early '69 Alternator Clarification

[Jeffrey S.]

Re: Early '69 Alternator Clarification

Here's one for sale on theCorvette Forum that fits the date range for an October "68 car I have no connection to this seller and have no knowledge to its authenticity.

https://www.corvetteforum.com/forums/c3-parts-for-sale-wanted/4730405-61-amp-alternator-1100825-dated-8h6.html

Jeff

[Mike E.]

Re: Early '69 Alternator Clarification

Here's one for sale on theCorvette Forum that fits the date range for an October "68 car I have no connection to this seller and have no knowledge to its authenticity.

https://www.corvetteforum.com/forums/c3-parts-for-sale-wanted/4730405-61-amp-alternator-1100825-dated-8h6.html

Jeff

Interesting that seller quotes JG that 69 rear case should have rectangle above Delco logo and then shows picture without.

[Joe L.]

Re: Early '69 Alternator Clarification

Interesting that seller quotes JG that 69 rear case should have rectangle above Delco logo and then shows picture without.

Mike------


1969 alternators DO NOT have the small, raised rectangle beneath the Delco Remy script. Very late 1969 MAY have had it. 1970 do have it.

[Mike E.]

Re: Early '69 Alternator Clarification

Yes. Have a 70 rear case here now.

[Joe L.]

Re: Early '69 Alternator Clarification

I don't wish to muddy the waters in your quest to determine the appropriate alternator for your car, but just to provide a little additional information. In addition to the unique to 1969 rear case Joe L refers to the internals for early 884 alternators contained unique diode trios and regulators. The configurations of these early parts is radically different than the 1970 and newer parts. Some parts of the configurations are visible through the rear openings in the case. I doubt many judges are aware of this and we chose not to include it in the TIM&JG due to the lack of appropriate images. I have seen only one of these in my time of observing Corvettes and it was brought to my attention by the owner of that example. Since it applies to so few examples my opinion is it is over the top and not worthy of observing, but if you do find an appropriately dated 884 and the internals look strange -- or your rebuilder indicates something strange -- you may have the second example and I would appreciate some good quality photos. Please be in touch if this magic happens.
This is just one example of the joys of Corvette research.

Terry-------


I'm not sure of the differences in the internals. I have NOS examples of every rectifier (diode bridge/heat sink) that GM says was used on 1969-82 Corvette 10SI alternators. I'll have to dig them out sometime and see if there are visual differences. In any event, all of the rectifiers used on 1969-82 Corvette 10SI series alternators are functionally interchangeable so there is certainly no functional difference.

The primary difference between the GM #1100825, 1100882, and 1100884 is CLOCKING. All are 61 amp alternators. Clocking differences relate to the mounting configuration of the alternators which varies depending on other options. None of these alternators were supplied with installed pulleys or fans.

The GM #1100859 was a 42 amp alternator used on base engine applications without N-40 or C-60. It was supplied to PRODUCTION with an installed pulley and fan. It was clocked for this, particular application.

The GM #1100833 was a 42 amp alternator used on 427 applications without K-66, N-40, or C-60. It was supplied without installed pulley or fan and is clocked for this particular application.

By the way, 42 and 61 amp 10SI alternators differ only by the installed stator. All other internal components are the same. Thus, a 42 amp alternator can be converted to a 61 amp by changing the stator.

[Richard R.]

Re: Early '69 Alternator Clarification

Kevin,

Not to discourage you but it took me 5 years to find an appropriate dated 1100859 for my 69 L46 for a june 69 car. The earlier the build date the more difficult it will be since it makes the potential population available much smaller. ebay has them come up from time to time. But lightening can strike at any time. I found mine at carlisle from a fellow that was selling out extra parts he had from a couple of projects. Just a card table in front of a pickup. He had one and 1/2. the 1/2 was dated properly for my car. I bought them both and traded the other (it was an 8/68 dated) to get a complete rebuilt unit. I think the rebuilder got the better of the deal because of the August date. Still, I felt like I had won the lottery!

Rich

[Terry M.]

Re: Early '69 Alternator Clarification

Terry-------


I'm not sure of the differences in the internals. I have NOS examples of every rectifier (diode bridge/heat sink) that GM says was used on 1969-82 Corvette 10SI alternators. I'll have to dig them out sometime and see if there are visual differences. In any event, all of the rectifiers used on 1969-82 Corvette 10SI series alternators are functionally interchangeable so there is certainly no functional difference.

The primary difference between the GM #1100825, 1100882, and 1100884 is CLOCKING. All are 61 amp alternators. Clocking differences relate to the mounting configuration of the alternators which varies depending on other options. None of these alternators were supplied with installed pulleys or fans.

The GM #1100859 was a 42 amp alternator used on base engine applications without N-40 or C-60. It was supplied to PRODUCTION with an installed pulley and fan. It was clocked for this, particular application.

The GM #1100833 was a 42 amp alternator used on 427 applications without K-66, N-40, or C-60. It was supplied without installed pulley or fan and is clocked for this particular application.

By the way, 42 and 61 amp 10SI alternators differ only by the installed stator. All other internal components are the same. Thus, a 42 amp alternator can be converted to a 61 amp by changing the stator.

Jue. The most obvious difference I remember is that the projections of the diode trio were wire rather than the flat stamping on the later design. Yes, these early parts are functionally the same as the later parts and this owner has replaced those early parts with the later parts with no problem. He saved the early parts as a matter of curiosity and to show them to fellow enthusiasts.

[Edward C.]

Re: Early '69 Alternator Clarification

Interesting that seller quotes JG that 69 rear case should have rectangle above Delco logo and then shows picture without.

That is a restamped front case. Original front cases are not cleanly cast like the repro front cases are. They have lots of rough edges and flash. I’ll try to post up a pic of an original but anyone that knows what an original looks like can tell the difference right away. This is not the first time this seller has sold a restamped alternator on the forum but I can’t call him out without interfering in the sale. And other members actually defended him last time. It’s BS. Compare the original front case below to the sellers “pretty” front case. This one is a 1100881 dated 9A6 but it uses the same front case. Mines real. Sellers is a Restamp….. Not sure if this is mentioned in the new JG but it should be added next time it’s updated.
DABA3476-88B6-4C4B-82E4-F8238B4A463F.jpg

[E S.]

Re: Early '69 Alternator Clarification

Joe - My 9/69 (ser. # 30751)has the small rectangle, and I am sure it is original to the car.
E.J.

[Gary B.]

Re: Early '69 Alternator Clarification

So, the picture above is a real case?
Gary Bosselman

[Edward C.]

Re: Early '69 Alternator Clarification

So, the picture above is a real case?
Gary Bosselman

I believe it is. I have several. Do you disagree? I can show a better pic. I also have pics of “reproduction” front cases as well as the case from one of my cars (another L36 with a 1100881 dated M30 with the NS stamp I think) that has been garaged since 1978. All the repro cases have that very clean look like the one that was for sale. Whoever decided to recast them made the mistake of cleaning up all the mold lines.
AA94A5D6-B0E5-4BA7-BDE2-6A3FAF70736A.jpg

[Gary B.]

Re: Early '69 Alternator Clarification

To answer your question, NO, I don't disagree. I guess I have not noticed a difference. Shame on me? But then again, it's hard to know everything about these cars. Everyday, I seem to learn something new and then I try and add it to the TIM&JG.
I'll look through my stash of old alternators today, try and get some pictures. I'll add them to the TIM&JG. I see Leonard posted some pictures of a repo case. I might steel them, unless you post some.
Gary B

[Gary C.]

Re: Early '69 Alternator Clarification

Terry,
I have a 1100882 (not for sale) and I disassembled it many years ago and took many photos of the components. I believe the diode trio was like you identified with the three diode with wires projecting out from the center to the ends. Photo attached.
Thanks,
Gary
1969 1100882 diode trio.jpg

[Joe L.]

Re: Early '69 Alternator Clarification

Terry,
I have a 1100882 (not for sale) and I disassembled it many years ago and took many photos of the components. I believe the diode trio was like you identified with the three diode with wires projecting out from the center to the ends. Photo attached.
Thanks,
Gary
[ATTACH=CONFIG]116793[/ATTACH]

Gary------


This diode trio is the one that is completely internal to the alternator and cannot be viewed through the slots in the rear case half. I believe that Terry was referring to the diode bridge/rectifier which can be partially seen through the slots in the rear case half. That's the one I'm interested in, too. Do you have photos of this part that you removed and can post here? Also, did you remove and replace the internal voltage regulator and, if so, can you also post those here?

Also, what is the date code on this alternator?

[Chris H.]

Re: Early '69 Alternator Clarification

Not sure if this is helpful or not. Photos from my Dec ‘68 L71.