Alternator bracket woes

When I picked up the corvette from the shop, I was informed that there was an issue getting the belt tension correct. Apparantly the bracket wasn't correct and no amount of changing belts would fix it, there was simply no room for adjustability. I was a bit confused since the Corvette still probably possesed many cobbled together systems from my father. I also wasn't about to wait to pay the shop to endlessly bang their head against a wall any longer either.

Turns out, they understated the alternator issue. The belt was so loose, that above 2.5k rpm it emitted a migraine inducing screech that drowned out the engine... and this is a 383 with straight side pipes. I was a bit bummed as it really detracted from all the money I'd just spent on a great engine, which combined with the migraine I got from driving home for 2 hours really left me miffed.

I inspected the issue myself to evaluate what was going on. The alternator could only be adjusted aproximately .75" with the current setup, at which point it either hit the end, or the alternator hit the bottom bracket. The shop was correct that something in the bracket combination was incorrect.

This began an annoying search for a solution. Nobody stocks alternator brackets because they aren't wear items, so comparing my parts to see if I had incorrect parts was not in the cards. Specs for the alternator brackets were spotty to non-existant, as almost no one has this issue. This made troubleshooting things tough... so I turned to the internet with a theory. I believed my upper alternator bracket (the long hooked bracket) to be too short, as there was still 4" left to slide an alternator in theory, but the bottom bracket prevented this.

After some discussion online over at Corvette Forum, including a few people just telling me to adjust the alternator shorter and get a shorter belt (completely blowing by me saying that wouldn't work)... I got a productive answer. The alternator bottom bracket on the car was wrong! Apparantly specific to the chevy small block 350 the lower alternator F bracket needs to have it's holes drilled offset towards the top so as not to impede the alternator. The very common F bracket is very similiar to all other manufacturer F brackets, but infact the holes for mounting the alternator are different... and so it's very easy to install the wrong bracket. Whether this is the shops fault or my fathers, I will never know... but I do know I've got the wrong bracket, and finding a new one is difficult as the images of all the new ones show them not offset.

Another suggestion from the discussion, was to use some washers to space out the bottom of the alternator a bit, gaining some tension. I figured for the $2 in washers it would cost me, why not! Sure enough, jamming two washers in per side allowed me to gain a bit of extra tensions and resolve the issue enough that I felt I would be fine in the corvette. This still was imperfect, but was an improvement. A solution was needed!

Alternator Bracket Solution:

The shop had recommended I install a different alternator bracket, but proceeded to link me to a bracket that would not easily work due to requiring a relocation of the alternator accross the car, which comes with significant wiring problems. I then tried an inward mount style alternator bracket from summit racing, with no luck. After returning to my research with a better understanding of the dyanmics of the issue, I discovere the Ultra Style Outward Mount Alternator Bracket from Mach Performance. The bracket arrived a few short days after ordering, mounted on the Corvette without issue and snugged the alternator right up nearly perfect. Some light adjusting of the bracket to center the alternator was required, but the product was truly amazing. Alternator headaches, be gone!