Correct alternator

[Roger D.]

Continuing my E69 Base Model SB coupe with no AC. Is the proper alternator a 42 amp #1100696. Since my build date is Oct. 4 1968 would an 8 A 12 unit work for NCRS. If not what would I be looking for.
Thank You
Roger

[Edward B.]

Re: Correct alternator

Continuing my E69 Base Model SB coupe with no AC. Is the proper alternator a 42 amp #1100696. Since my build date is Oct. 4 1968 would an 8 A 12 unit work for NCRS. If not what would I be looking for.

No, you need a 1100859 alternator. The date you should be looking for would be late September, 1968.

The 1100696 alternator was externally regulated. Starting in the 1969 model year, the Corvette alternator was internally regulated so if you get a 1100696, you won't be able to use it on your car.

Ed

[Roger D.]

Re: Correct alternator

Thank you Edward for the date I need and unit #
Roger

[Edward B.]

Re: Correct alternator

Roger, make sure you're sitting down when you DO find one. You're about to drop close to a grand for a "correct, date coded" 859 alternator!

However, if you're patient and can wait, the deals ARE still out there. For example, I was looking for a 1100884 for my very late 69 (October, 1969 build) for a few years and I refused to pay stupid ebay prices. I finally found one on the internet for $200.00 plus shipping. It had two issues. It wasn't a good date for my car and it had a dent in the housing where someone had dropped it. I don't show my car (and it has power steering so the date isn't even seen when it's mounted) so I didn't care about the date, and the dent didn't affect the operation, so all I did was take a little JB weld and filled it in. You can't even see the dent anymore. I also had it rebuilt by a local alternator shop here in town for another $50, so basically I got a $1k alternator for $250!

Why so expensive? Because the 1969 Corvette (and 1970 Corvette) alternators were "one off" designs and rare. But keep doing Craigslist and ebay searches and you'll eventually find one that has a price tag that's reasonable. If you don't care about dates, that makes it even better. If you do, it'll take a lot longer to find one, and you'll probably have to pay the price.

Good luck
Ed

[Roger D.]

Re: Correct alternator

Roger, make sure you're sitting down when you DO find one. You're about to drop close to a grand for a "correct, date coded" 859 alternator!

However, if you're patient and can wait, the deals ARE still out there. For example, I was looking for a 1100884 for my very late 69 (October, 1969 build) for a few years and I refused to pay stupid ebay prices. I finally found one on the internet for $200.00 plus shipping. It had two issues. It wasn't a good date for my car and it had a dent in the housing where someone had dropped it. I don't show my car (and it has power steering so the date isn't even seen when it's mounted) so I didn't care about the date, and the dent didn't affect the operation, so all I did was take a little JB weld and filled it in. You can't even see the dent anymore. I also had it rebuilt by a local alternator shop here in town for another $50, so basically I got a $1k alternator for $250!

Why so expensive? Because the 1969 Corvette (and 1970 Corvette) alternators were "one off" designs and rare. But keep doing Craigslist and ebay searches and you'll eventually find one that has a price tag that's reasonable. If you don't care about dates, that makes it even better. If you do, it'll take a lot longer to find one, and you'll probably have to pay the price.

Good luck
Ed

Thanks Ed, I know they were very expensive and I am not in a big hurry so I will take your advice and keep my eyes peeled for one on the places you mentioned. Thank you for your help.

[Edward B.]

Re: Correct alternator

Roger, after 45 years and MANY rebuilds, a lot of the "correct" alternators no longer have the "correct" rear case. When you DO find one, make sure it has the fins in the back (see pictures below).

Ed

[Roger D.]

Re: Correct alternator

Roger, after 45 years and MANY rebuilds, a lot of the "correct" alternators no longer have the "correct" rear case. When you DO find one, make sure it has the fins in the back (see pictures below).

Ed

I will do that Ed. I would assume that I would still use a 42amp alternator just to run the car and drive it?

[Edward B.]

Re: Correct alternator

Yep. Any internally regulated alternator will work until you can get the "correct" one.

Ed

[Terry M.]

Re: Correct alternator

Roger, after 45 years and MANY rebuilds, a lot of the "correct" alternators no longer have the "correct" rear case. When you DO find one, make sure it has the fins in the back (see pictures below).

Ed

Ed
Your second photo shows the rear case of a either very late 1969 or more likely 1970 alternator.
The fins you cite are the same 1969 or 1970, but the attachment for the bolt to hold the wire harness (about 4 o'clock on your photo) has the height of late 1969 or 1970. Earlier 1969 high-output rear cases had the bolt hole flush with the rear of the case.
There is nothing easy about identifying alternator components of this transition period. There are other internal differences for early 884 alternators in the construction of the diode-trio, the internal regulator, and the brush holder. Most of these differences are all but invisible when the alternator is installed on the car, but some of them can be seen with enough time and effort.

[Edward B.]

Re: Correct alternator

You are correct as usual Terry! I was just using that picture as a reference for the 7 cooling fins.

But as you pointed out, here's a 1100825 dated 8J27 (September 27th, 1968) for an early 69 Corvette. Notice the difference between the height of the wire harness clip bolt hole -vs- the one shown above (which is dated mid December, 1969). I'm not sure when the changes took place but yes, there are a few minor differences between early 69 and late 69-70 alternators.

(The one you'll need will look like this one Roger.)

Ed

[Terry M.]

Re: Correct alternator

You are correct as usual Terry! I was just using that picture as a reference for the 7 cooling fins.

But as you pointed out, here's a 1100825 dated 8J27 (September 27th, 1968) for an early 69 Corvette. Notice the difference between the height of the wire harness clip bolt hole -vs- the one shown above (which is dated mid December, 1969). I'm not sure when the changes took place but yes, there are a few minor differences between early 69 and late 69-70 alternators.

(The one you'll need will look like this one Roger.)

Ed

Very nice pictures Ed. Well done.

[Edward B.]

Re: Correct alternator

Thanks Terry. By the way, do we have any idea when the rear case changed? I've not done that much investigation into this. The raised bolt hole and the raised pad under "Delco-Remy", are the two things that really stand out between the later and earlier housings.

Ed

[Terry M.]

Re: Correct alternator

Thanks Terry. By the way, do we have any idea when the rear case changed? I've not done that much investigation into this. The raised bolt hole and the raised pad under "Delco-Remy", are the two things that really stand out between the later and earlier housings.

Ed

I don't have an exact date for the change and have not participated in a discussion or research of that. It is likely too late for that kind of research as too few unmolested examples exist now. We are our own worst enemy to quote Pogo.

[Edward B.]

Re: Correct alternator

It is likely too late for that kind of research as too few unmolested examples exist now. We are our own worst enemy to quote Pogo.

Thanks Terry, and yes, I agree.

Ed

[Michael B.]

Re: Correct alternator

Just for giggles I too have an Oct 4 68 build date 427/400 with TI. It has a 1100825 Alt dated 8H27 (August 27, 1968) and a 6 spoke front case.

Mike