1100884 spoke question

[D S.]

Were there ever any 1100884s normally produced with five spoke fronts? I have only seen six spoke fronts (including the one on my 1970) but a person looking for one says he is certain some were five spoke.

Thanks,
Scott Sims
Texas Chapter

[Mike E.]

Re: 1100884 spoke question

Scott,
Is a 1100884 an alternator?

Mike

[D S.]

Re: 1100884 spoke question

Mike, when I did an archive search for that number all the posts referred to an alternator. So, yes, it is an alternator. Do you know whether the 1100884 were all six spoke fronts or have you seen some with five spoke?

Thanks

[Joe L.]

Re: 1100884 spoke question

Were there ever any 1100884s normally produced with five spoke fronts? I have only seen six spoke fronts (including the one on my 1970) but a person looking for one says he is certain some were five spoke.

Thanks,
Scott Sims
Texas Chapter

Scott-------


I don't know, for sure. However, I think it's possible that late 1970 alternators could have used the "5 spoke" drive end case. Part number research will not resolve this one; I've tried for years. As far as I can determine, the design of the drive end case of the SI series alternator changed at least 3 times between 1969 and 1973 but the part number never changed. I'd love to get my hands on the blueprint for that drive end case part number but I've never been able to.

[D S.]

Re: 1100884 spoke question

Thank you, Joe. That guy I referred to may have a long search or someone will "build" a five spoke just for him. From what I read those correct rear cases are impossible to find.

Scott

[Joe L.]

Re: 1100884 spoke question

Thank you, Joe. That guy I referred to may have a long search or someone will "build" a five spoke just for him. From what I read those correct rear cases are impossible to find.

Scott

Scott-----

The 5 spoke drive end cases are just about as rare as the 6 spoke. The 6 spoke were used from 1969 through most, if not all, 1970. The 5 spoke was used, possibly, from late 1970 through most, if not all, of 1971. I've never found an NOS 6 spoke or 5 spoke drive end case and I've looked for years. I do have an NOS 1100543 [not for sale]. It has a 1970 manufacturing date. It has a 5 spoke drive end case. However, it also has the 1971+ style slip ring case end.

The 1969 slip ring case half is unique to that year, although I suppose it's possible it did carry over into very early 1970. The 1970 slip ring case half is unique to 1970, although likewise I suppose it's possible it carried over into early 1971 (although the early 1100543 I have does not have it). Both the 1969 and 1970 slip ring case halves are VERY, VERY difficult to come by. I've NEVER found an NOS example but I have several used examples [none for sale].

[Wayne M.]

Re: 1100884 spoke question

From a C2 perspective, is this the 6-spoke drive end you guys are referring to ? As for the C.E (commutator end, or slip ring end), can you describe (a
picture would be better) what the difference is from the C2 era ?

[Edward B.]

Re: 1100884 spoke question

Wayne, all C2's (and the C3 1968) alternators were the 10-DN externally regulated version. Starting in 1969, the Corvette was built with the new internally regulated 10-SI alternator. As this alternator generated more heat, the engineers designed it to use the 6 spoke (very think ribs) drive end so it could move more air, and a special rear case with 7 cooling fins. There were two rear case designs with the first having a very slight rise in the bolt hole and the later design having a more pronounced rise and in a different location. Compare the two pictures below and you can see the differences.

Ed

[Bill W.]

Re: 1100884 spoke question

Ed what were the years of the changes ?

[Joe L.]

Re: 1100884 spoke question

From a C2 perspective, is this the 6-spoke drive end you guys are referring to ? As for the C.E (commutator end, or slip ring end), can you describe (a
picture would be better) what the difference is from the C2 era ?

Wayne-----

This is the 1969-70 drive end (front) case. As far as I know, it was never originally used for any DN series alternator application. However, I believe it can be used as a replacement for a DN series alternator. It was never cataloged by GM that way, but, if I recall correctly, it can be used. The DN series drive end case was much more "closed" and is actually somewhat similar to the late 1971+ SI series drive end case.

Edward has pictured the 1969 and 1970 slip ring end (rear) case halves. These cannot be used on a DN series alternator. The 1969 case half has the nearly flush grounding lug. The 1970 case half has the raised grounding lug. It also has the slightly raised rectangle under the Delco-Remy script.

The 6 spoke and 5 spoke (~1971) drive end case halves and the 1969 and 1970 slip ring case halves are extremely rare. That's because during these model years, the SI series alternators were used almost exclusively on Corvettes, although I think there were a few other low-production GM models that might have used them (of course, the stamped-in alternator part numbers were definitely unique to Corvettes). Many of the 1969-71 Corvette alternators were unwisely turned in as cores when alternator replacement time came so these rare cases are "floating around" out there in the world of automotive rebuilt alternators. However, the 6 and 5 spoke drive end cases are quite fragile. I've been told that commercial rebuilders just threw them in the scrap heap when they came across them.

[Joe L.]

Re: 1100884 spoke question

Ed what were the years of the changes ?

Bill------


The case half on the left was used for 1969, although it's possible it might have carried over into very early 1970. The case half on the right was used for 1970, although it's also possible it carried over into very early 1971. VERY rare case halves for both drive end and slip ring end. That's why it's hard to counterfeit a 1969-70 alternator part number because the case halves themselves are quite rare and all the part numbers are valuable in their own right.

Years ago I knew a guy that had a 1969 Corvette with its original alternator. The car was stolen. When it was recovered several days later the only thing missing was the alternator.

[Edward B.]

Re: 1100884 spoke question

Edit - Joe already answered so I'll clear my reply.

Ed

[Joe L.]

Re: 1100884 spoke question

If you mean the 10-SI internally regulated alternator (and going by my pictures above), early 1969's (starting August, 1968) used the alternator on the left with the shallow bolt hole and later 1969's and all 1970's used the alternator on the right with the higher bolt hole. Sorry but I don't know the exact changeover month.

Ed

Ed------


I've never seen a known-original 1969 with the 1970 style slip ring end case. My original owner 1969 built in mid-September, 1969 has the case style shown on the left.

[Edward B.]

Re: 1100884 spoke question

You're probably right Joe. Mine's not original to my car (it's dated mid December, 1969) so it's probably for an early 1970. It's the version I show on the right (that's actually my alternator).

Ed

[Joe L.]

Re: 1100884 spoke question

You're probably right Joe. Mine's not original to my car (it's dated mid December, 1969) so it's probably for an early 1970. It's the version I show on the right (that's actually my alternator).

Ed

Ed------

Except for the 1100884, 1969 alternator part numbers were different than 1970. So, unless it's an '884' it should be clear which model year it was intended for. However, I would not be surprised if a very late 1969 alternator used what is considered the 1970 slip ring end case. And, I would not be surprised if a very early 1970 alternator part number used the 1969 slip ring end case half. The parts are 100% functionally interchangeable and I'm sure Delco-Remy knew that.