Nostalgic Air system uses the same brackets as classic air and they recommend a single belt drive.

To my mind that is way too much load on one belt. Check ot '70's cars they ran two belts. I had an Aussie Ford in the nineties that ran three belts, one for alt/water pump, one for a/c and another for the power steering.

I don't think an idler pulley would help in this situation as you would end up with even less contact area driving the alt or a/c. Belts will slip when the tension is not right or their isn't enough contact area to drive whatever. If you have a 63 Amp alternator it is producing the best pat of 1 horsepower in electricity and in the real world needs almost 2HP to drive it. The a/c is in the same situation.

A dual pulley system with two belts driving both would eradicate the problem or run the a/c off the separate pulley.

Also make sure you are using the right belt width as this may also cause slippage.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Is the problem that when the alternator is charging AND THEN THE A/C is turned on that the noise starts? And that just running with the belt on both the alt and the A/C pulley there is no belt noise.

If so, is the belt wide enough for the pulley/pulleys? Sound like a belt is slipping so what happens if you spray some belt dressing when the noise occurs?

Is there a idler pulley in your system? I had a Mustang that only howled with the A/C on and it was a bad idle wheel bearing.

The A/C clutch is only engaged with the A/C on and you say it only makes noise with both on so it could be the A/C clutch. Pete

So, I have the Nostalgic air (N.A.P) system for the Y-Block which also includes the bracketry to locate the compressor on the bottom passanger side of the Y-Block, and the 10si GM alternator on the upper passanger side. MY problem is....

I CAN get the 3-wire to charge by self exciting (reving past a certain RPM) it

I CAN get the A/C to blow Cold

But I CAN NOT get them to do both at the same time without the compressor screaming like a banshee

It's as if though the system can't take the extra load? Someone suggested that there might be a power problem and that there's not enough juice to the system, but I find that hard to believe (63 AMP alternator). Has anyone else had this problem or know what it could be.

Facts:

Charges 13.4 Volts unloaded, 12.9 Volts load

It doesn't squeal until it drops under 13 volts

The belt IS tightened

It looks to me that it's screaming because it gets stuck or something

Any suggestions are highly appreciated.

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic