Since I have had my vette, I have always had a problem with the Alt. belt squealing. I've tried different belts, with the same results. When the belt is tightened properly, I can rev to 3500rpm with no problem. Once I hit 4,000rpm, the belt begins it's squealing. If the belt is just a little loose, it will squeal at 2,000rpm, and if I overtighten it, it might be good to 5,000. But, I don't want to overtighten, because it can ruin the bearings in the Alt and Water Pump.

This kind of sucks, because with a 3.70 gear ratio, I'm always turning high rpm's. In addition, the new engine loves to rev; it starts pulling good around 3,000rpm, and revs to just past 6,000rpm.

Now what happens if I rev to 6,000rpm for more than just a few seconds?


I need to get this problem solved. I've tried cleaning the pulleys, making sure everything is aligned, and using different belts. Nothing seems to work. I think it's just the pulleys that are faulty.

So, here is what I am considering.
Option 1, install a double pulley on the Alt. I have extra grooves on the crank and water pump to run this. So with two belts, would this split the load and reduce or eliminate the squealing?
Option 2, install a set of Mach performance pulleys. They look really nice, and I think their deeper grooves would help a lot. Plus, since my engine is always revving high, I could opt for the slower turning ratios to slow down the belt speed, and maybe gain a few hp.
Option 3, install a serpentine belt. This seems like a nice alternative as well.
Option 4, Go all out, and convert to electric fan, electric water pump, electric ps, and just have a belt dedicated to the Alt only. (This option sucks :D )

 

That is an ugly looking belt. Without your detailed analysis, one would think that the problem was alignment. How did you determine that the squeal is from the belt, and not from the pulley bearings?

The remedies you provided all have merit. I guess you should be the one to make that decision based on cost and serviceability. Without sounding stupid, if the squeal is from the belt, you might apply a dab of belt dressing before modifying the pulleys.

 

First, it's not the PS belt, because I actually left it off to see if the squeal is still there, and it was. I'm only running two belts, so that leaves the other one.

I'm sure it isn't the bearings, because in the time that I've had the car, I've changed the alternator and water pump. In fact, I have a different engine now. The only thing that hasn't changed is the pulleys themselves.

I might give it another try. In the past I tried some, but it didn't make any difference. But, that was with the el cheapo belt(in the picture). I bought a high quality belt this time, so maybe it would help :cheers:

 

One thing that I should clarify is that the belt you see in the picture happened when I was racing another car. I was in excess of 5,000rpm quite a bit, so no telling what the poor belt was going thru :lol:

Prior to that, the belt had been on the car for almosta year, in daily driving conditions. This is why I think it's rpm related.

 

Make sure that the pitch of the belt is the same as the pulley's. I've seen cases where the pulley on a rebuilt alternator had been replaced with an incorrect one. The end result was that only part of the belt contacted the pulley. The same problem could occur if the drive pulley were incorrect.