Alwyn678

Which belt is this? I just put on a new alternator belt so I am sure that is not it. The A/C is Not hooked up. Other than the squeal all is well. What is the issue?

Gracias

atthemattin

I could be wrong with the belt layout, but if you don't have an belt running to the AC, then it could be your waterpump. I know the non AC cars have a separate belt running to the pump, since you don't have one and your AC belt isn't there, then maybe that? Basically it's your alternator belt because it is running more load turning your pump

Alwyn678

I am gonna check the alternator belt again. Maybe it has stretched some slack on the belt. So I guess the a weak Is the belt losing traction under hard acceleration. I guess I shouldn't tighten the as A/C belt and see if the problem is solved.


What do you think?+

'75

AC cars have a more aggressive fan that takes more power to run. If you don't have the AC belt on, then the alternator belt is trying to do all the work and will squeal like yours.

Alwyn678

Must I put the A/C belt on to fix the problem?

'75

There's another way. If you find a belt exactly the right length to go from the fan to the crankshaft, Some earlier cars did this to prevent the belt squeal.

atthemattin

If you do go the pump to crank route, let me know what belt you end up getting. I'm in the same boat minus the squeal, but I want the belt there just to be safe. That said, I know that Bob a/c cars from 72 and older ran the pump to crank set up. Not sure which years it ran through, but I'm pretty sure 72 did it

Alwyn678

I will see what happens. My Vette is a 74-

augiedoggy

I get the same squeal, good info.. thanks. likely a loose belt in my case since I do have the ac compressor in the car.

71scgc

My '71 charges just fine with only the alternator belt, and doesn't squeal.
That said, I would like to have the crank to water pump belt.
If I could only find the correct size!!!!

A/C cars use a different size crank pulley than the non-A/C equipped cars. There seems to be no consensus on which belt fits. One that works for one car won't necessarily work on another, even if the cars are the same year. You just have to go trial and error mode to find the one that fits, and even then you might not find one that works.
Many factors at work here:

Depth of the pulley grooves
Length of belt
Width of belt
Profile of the belt
Size of pulleys (all of them)

I've been trying to find a belt that will work on the engine I built using the pulleys from my old engine. Luckily the belts are cheap.

This has come up before on here, and there are some belt part numbers that others have had success with.

Somewhere...

Carter

gkull

tires squeal when they loose traction and so do belts. Belts age and some brands are inferior. You want belts that over fill the pulley. You can also rough sand the pulleys to give them more traction.

Alternators have a max rpm. Like this Powermaster is max of 17,000 rpm and then it might fly apart So if you have for example a 6 inch crank pulley and a 2 inch alternator and run your motor to 6000 rpm. You can blow up the alternator.


That big metal fan also has a max rpm. It is hard for a belt to accelerate that big heavy clutch fan that my L-82 came with and I thought it was dangerous with my modded L-82. I experienced belt squeal. So I went to an 18 inch 10,000 rpm stainless steel flex fan, 1/3 the weight and it could move as much air as the stock fan. Later I went Spal fans

Because my motor does 7500 rpm. I have a smaller aluminum crank pulley and larger diameter alternator pulley.

mrvette

Age 72, OLD hotrodder here, I noted the change from SAE to Metric over the years, and was slo on the uptake when they basically quit making old belts.....

here is the trick, the pitch of the V was changed, so the metric is wider, they give you a belt of about 7/16 across the back instead of 1/2" and so it rides lower in our pulleys, so that it rides on the TOP of the belt and not the whole thing down at the crotch of the V.......note the back of the belt is in fact probably in a U shape, not FLAT......note the wear pattern of the belt, worn on the shoulders but not the crotch.....

gotta ask/order/.net a olde tyme belt......

been a few decades......

Staylor63

Also check your fan clutch....that's where my squeal ended up coming from.