Originally Posted by Dmgarage
I know this topic has been covered in depth. I have spent a couple hours reading and several more hours trying to figure this out. 400 hp SBC. I CANNOT get rid of the squealing belt that goes from the crank, around wat pump to alt. I know it is this belt as I have taken the others off. The squeal is not constant, it seems to occur mostly on deceleration. I have tried: different belt, different alt, different bracket system, TIGHT belt, loose belt. I have an edelbrock high volume water pump. I am wondering if this pump overcomes the belt since there is not a lot of belt coverage on the water pump pulley. ANy help is greatly appreciated. I to attached PICS. The pulleys are aligned. GM pulley on the crank and the water pump.
I have a similar set up on the 350 in my S15 which did the same thing when I installed the Edlebrock water pump with aluminum pulleys when operated only with a single belt as you have. When I put the inboard belt on that runs only between the the crank and pump the problem went away. It appears the high volume Edlebrock is more resistant to rotational speed changes to where a single belt just doesn't provide enough grip in these situations.
At this point your pulleys may be glazed so when you take this apart it will be a good idea to lightly sand the inside of the grooves so there is some "tooth" for the belt to bite into.