What's the bolt boss on alternator case ?

[Wayne M.]

White arrow points to title subject. Looks like it would be for a mounting bracket. Beside it is a case from 1100669 3M17 42 A. Did any C2's come with the bolt hole, or is it found on a later version of the 10DN alternator, probably non-Corvette ?

alt bracket boss ?.jpg

[Loren L.]

Re: What's the bolt boss on alternator case ?

Could it be the back half from a totally different alternator, cobbled together by a rebuilder?

[Mike M.]

Re: What's the bolt boss on alternator case ?

i agree with loren. the back half of the case is beyond the c-2 era. mike

[Joe L.]

Re: What's the bolt boss on alternator case ?

White arrow points to title subject. Looks like it would be for a mounting bracket. Beside it is a case from 1100669 3M17 42 A. Did any C2's come with the bolt hole, or is it found on a later version of the 10DN alternator, probably non-Corvette ?

[ATTACH=CONFIG]60700[/ATTACH]

Wayne------


The last year the 10DN series alternator was used on a Corvette was 1968 and this configuration case was not used for 1968 (or, any earlier 1962-67 Corvette application). I don't think this configuration was used on any Chevrolet passenger car. My guess would be some truck application or, possibly, some non-Chevrolet GM passenger car.

By the way, is there a casting number found anywhere on the inside of this case?

[Mike M.]

Re: What's the bolt boss on alternator case ?

i have a similar alternator off a K-20 1974 blazer with 350 ci. mike

[Joe L.]

Re: What's the bolt boss on alternator case ?

i have a similar alternator off a K-20 1974 blazer with 350 ci. mike

Mike------


Yes, I have confirmed that a 10DN series alternator with the rear case half configuration shown in the photo was used in Chevrolet trucks. However, the latest I can find that the 10DN series alternator was used in trucks was 1972. So, I'm somewhat surprised to learn that you have one in a 1974.

[Mike M.]

Re: What's the bolt boss on alternator case ?

joe: u are almost certainly correct. i junked the blazer years ago and it was probably a 72, not a 74. senility settin in. . i pulled the alternator and its dated in late 71. mike

[Duke W.]

Re: What's the bolt boss on alternator case ?

Could that threaded boss be for a ground wire? The 10SI in my Cosworth Vega has such a boss for a dedicated ground wire because the alternator is mounted with rubber bushings to isolate it from the four cylinder's unbalanced second order vertical shaking force that I've computed to peak at 16g/233Hz at 7000 revs.

The rubber bushings may have helped, but the vibration still wreaked havoc with the side connector and regulator spades.

Duke