[allenga]

Originally Posted by antique69lemans

Are you using a cogged belt ? They seem to get better traction. Maybe that belt is glazed.

Yes, cogged belt. Brand new, still slip

[OG68]

Try the Goodyear Gatorback belt. Solved my squealing problems.

[Schurkey]

You sanded the pulleys. Did you sand the sides of the belt?

[allenga]

Originally Posted by Schurkey

You sanded the pulleys. Did you sand the sides of the belt?

I put brand new belts on today

[Bentwheelbob]

You are chasing butterflies. There is no reason a stock engine in good tune should require a severe duty fan clutch to get proper cooling. I have a 462 stroker in my Y88 with stock everything including radiator, fan clutch and water pump, and it never goes above 200 degrees. Your belts didn’t squeal until you made the clutch change so surely you are smart enough to know that’s your issue.

What is the history on your radiator?

Please don’t change to some incorrrect AC compressor before you solve this problem.

[allenga]

Originally Posted by Bentwheelbob

You are chasing butterflies. There is no reason a stock engine in good tune should require a severe duty fan clutch to get proper cooling. I have a 462 stroker in my Y88 with stock everything including radiator, fan clutch and water pump, and it never goes above 200 degrees. Your belts didn’t squeal until you made the clutch change so surely you are smart enough to know that’s your issue.

What is the history on your radiator?

Please don’t change to some incorrrect AC compressor before you solve this problem.

Entire cooling system brand new including Cold Case radiator.

[Bentwheelbob]

It’s not your fan clutch unless the old one was not working. Did you check it to see if it worked? Slow down.


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[Old Goat 67]

I'm with Bob.

[Schurkey]

Originally Posted by Bentwheelbob

You are chasing butterflies. There is no reason a stock engine in good tune should require a severe duty fan clutch to get proper cooling.

Originally Posted by Old Goat 67

I'm with Bob.

Hell, yes.

[allenga]

Originally Posted by Schurkey

Hell, yes.

Great feedback..

[Formulajones]

I run the heavy duty clutches on all the clutch fan cars here except one. So that's 4 different cars equipped with heavy duty clutch fans. The 5th one is a standard clutch fan.

No problems with any of them squealing belts. Never tried the severe duty unit. Never felt I needed to, I don't have anything here that runs above 185 degrees in the AZ summer heat.

I did find that cheap belts are just that, and pulley alignment also plays a roll.

[allenga]

Originally Posted by Formulajones

I run the heavy duty clutches on all the clutch fan cars here except one. So that's 4 different cars equipped with heavy duty clutch fans. The 5th one is a standard clutch fan.

No problems with any of them squealing belts. Never tried the severe duty unit. Never felt I needed to, I don't have anything here that runs above 185 degrees in the AZ summer heat.

I did find that cheap belts are just that, and pulley alignment also plays a roll.

Thank you. What cars are you running..

[Formulajones]

They are all classics. One that has a heavy duty clutch fan is my Firebird and I daily drive that one. The other classic daily driver has the standard clutch on it.

The bird doesn't have AC and has the standard larger diameter pulleys on it, they turn a bit slower.

I have a big block chevelle with the heavy duty clutch fan, and it's an AC car with the smaller pulleys, and that one works fine as well. I did have pulley alignment issues with that one when it was going through water pumps. Seemed at the time you couldn't get a decent remain pump that had the shaft pressed in the right depth. After that was figured out it never squealed another belt. That's been 20 years ago now.

[allenga]

At the risk of getting harpooned by some not as patient...

To test, I put back the original standard duty fan clutch and still had belt squealing. I cleaned up all the pulleys and put new belts. Still squealing. I narrowed the squeal down to the alternator belt and then removed it and all squealing stopped.

When I look closely at the pulley alignment, it looks like the water pump pulley is out forward now causing a parallel misalignment. The power steering belt is quite no noise despite a little parallel misalignment.

All my factory brackets and spacers are back on just as they were.

Scratching my head here. Seems like with this Flowkooler water pump, its like I have to shim the alternator pulley to make this work now....

[Grand73Am]

I know you said the belts are tight, but did you measure the belt tension with a gauge? Many times what we think is tight is not tight enough according to factory specs. There are V-belt tension gauges available from parts stores or online for about $16. The belt tension specs are in the Engine/engine cooling/accessory drive belts section of the Pontiac Service manual for your car. One of those inexpensive gauges probably isn't real accurate, but it should get you closer to the tightness you need versus just guessing. Works for me.

So, if aligning your pulleys don't solve your problem, tightening to factory specs measuring with a gauge, might help, if you aren't already doing that.

[PunchT37]

I can't keep cogged belts on my car. Seems they have less traction as the gaps in the cogs provide less contact in the V groove.

[Squidward]

I run the 2797 on my Firebird with a 6.5" double groove WP pulley. It keeps my biz cool. I do get squeal at times above 3k rpm. Last time I replaced the belts, tho, everything was fine, no squeal, and that included time at the track running the engine up to 5k. I suspect my belt tension has decreased since then.

I used to run the same 2797 on my Lemans, but had squeal on that car too. During troubleshooting I noted that I had a bent fan blade, so I put on a spare flex fan. That squeals, too. I suspect I need to check belt tension.

I have a 9799130 pulley (7 3/16") that I might try on the Firebird to see if it makes a difference. I'm currently running a SBC wp pulley that has roughly the same diameter and backspacing as the 9799128 wp pulley to convert 67-69 accessories for use with a long nose pump.

Good discussion.

[Formulajones]

Originally Posted by allenga

At the risk of getting harpooned by some not as patient...

To test, I put back the original standard duty fan clutch and still had belt squealing. I cleaned up all the pulleys and put new belts. Still squealing. I narrowed the squeal down to the alternator belt and then removed it and all squealing stopped.

When I look closely at the pulley alignment, it looks like the water pump pulley is out forward now causing a parallel misalignment. The power steering belt is quite no noise despite a little parallel misalignment.

All my factory brackets and spacers are back on just as they were.

Scratching my head here. Seems like with this Flowkooler water pump, its like I have to shim the alternator pulley to make this work now....

That's what I eluded to in my earlier post. In cases like this I usually find there is a pulley out of alignment, even just a slight amount. I even mentioned it was an issue with my BBC when going through water pumps, the reman pumps weren't getting the shaft pressed into their proper location and I actually had to put a puller on it to pull it back out a bit.

The flowcooler pumps are where that all started for me about 20 years ago. They really don't have a great reputation, I had 3 of them spring leaks within a few thousand miles. Even today people like Ron Davis who builds some of the nicest radiators in the country absolutely hate flowcooler pumps and any kind of a cooling issue he'll tell you to rip that thing off. I'm not a fan of those things either after my experiences. It's even hard to get a decent remain pump from a parts store these days, most are aftermarket castings now. But one thing is for sure, tweaking the depth of the pump shaft has been a pretty common occurrence with remain pumps, at least from what I've seen anyway.

[allenga]

Originally Posted by Formulajones

That's what I eluded to in my earlier post. In cases like this I usually find there is a pulley out of alignment, even just a slight amount. I even mentioned it was an issue with my BBC when going through water pumps, the reman pumps weren't getting the shaft pressed into their proper location and I actually had to put a puller on it to pull it back out a bit.

The flowcooler pumps are where that all started for me about 20 years ago. They really don't have a great reputation, I had 3 of them spring leaks within a few thousand miles. Even today people like Ron Davis who builds some of the nicest radiators in the country absolutely hate flowcooler pumps and any kind of a cooling issue he'll tell you to rip that thing off. I'm not a fan of those things either after my experiences. It's even hard to get a decent remain pump from a parts store these days, most are aftermarket castings now. But one thing is for sure, tweaking the depth of the pump shaft has been a pretty common occurrence with remain pumps, at least from what I've seen anyway.

Thank you all. I thought I was going crazy..

[allenga]

After some "adjustments" and a Dayco Top Cog 15485 on the alternator, I have no more belt noise. Interesting, the Dayco is the widest alternator belt out of the three I bought. It rides a bit on top of the pulley. Its working so far today.

https://youtu.be/str8P5Oqyp8