This post uses pages from the 1960-64 Assembly Manuals to explain the different rear mounting brackets used for Corvair Generators.
The first two photos are from the 1960 Assembly manual, showing all three possible generators and their brackets:
Generator Part # | Bracket Part # | Bracket Length & Description |
1100357 (7″ short generator) | 3779301 | 7″ with bushing and strap |
1102226 (8″ standard generator) | 5769773 | 7″ with bushing and strap |
1105135 (35 amp HDLCI generator) | 3781099 | 7″ without bushing and with strap |
The 1960 mounting is also unique for not including the battery ground strap, as the battery was located on the right hand side of the engine compartment in that year. So, in place of the ground strap, there is an extra plain washer in the stack.
Next two photos are from 1961 Assembly Manual. Based on the drawings and a survey of cars, it appears that the reinforcing strap was eliminated this year and replace by a thick washer under each of the two bolts (“spacer” – see item #14, part number 36938530).
What is still unknown is whether or not the reinforcing strap continued to be used on the HDLCI generator.
Generator Part # | Bracket Part # | Bracket Length & Description |
1102226 (cars) – terminals face up | 3779301 | 7″ with bushing, no strap |
1102227 (wagons and FC) – terminals face back | 3779301 | 7″ with bushing, no strap |
1105313 (35 amp HDLCI generator) | 3781099 | 7″ without bushing. Unknown if strap used or not. |
Next two photos are from 1962 Assembly manual. Note that the bracket for cars and FCS is shortened this year. If you study closely, you’ll notice that they initially drew the page for the cars and FCS with the 3822687 bracket (no bushing) but then changed it to the 3813531 bracket with bushing. The 3822687 bracket does not show up again until 1964, when it is used on Powerglide engines.
Generator Part # | Bracket Part # | Bracket Length & Description |
1102226 (cars) | 3813531 | 4″ with bushing |
1102227 (wagons and FC) | 3813531 | 4″ with bushing |
1105313 (35 amp LCI) | 3813532 | 7″ without bushing. Unknown if strap used or not. |
Nothing changes in 1963:
Generator Part # | Bracket Part # | Bracket Length & Description |
1102226 (cars) | 3813531 | 4″ with bushing |
1102227 (wagons and FC) | 3813531 | 4″ with bushing |
1105313 (35 amp HDLCI Generator) | 3813532 | 7″ without bushing. Unknown if strap used or not. |
1964 introduces a new bracket for Powerglide engines – no bushing.
Generator Part # | Bracket Part # | Bracket Length & Description |
1102336 (35 amp) – all STD Trans | 3813531 | 4″ with bushing |
1102336 (35 amp) – all w/ Powerglide | 3822687 | 4″ without bushing |
1105313 (35 amp HDLCI Generator) | 3813532 | 7″ without bushing. Unknown if strap used or not. |
As for why they changed the 1964 Powerglide bracket to eliminate the bushing, we can only guess, but here is what Dave Newell says about it:
“My thinking on this is that with the change to the 35 amp generator for ’64 and increased engine displacement, those may have aggravated an idle buzz in Powerglide cars when in gear. Larry hit it on the head! Development engineers most likely caught the noise at the Proving Grounds (chasing buzzes, hums, vibrations and the like was their specialty 🙂
As to why they decided to keep the bushing bracket mount on manual trans cars, I’m sure there was a very good reason. It would have been cheaper all around to make the solid mount standard across the board.
I suspect the enginners wanted to preserve the shock load cushioning property of the bushing mount bracket (during sudden high RPM speed changes in manual trans gear shifts). With PG this wouldn’t matter as much, so they opted to kill the buzz with a solid mount.”