Correct fan belt?

[mcditalia]

Ok, so I tried to replace my fan belt the other day after I ordered a "correct" replacement cloth-wrapped fan belt from Zip products. I got the generator, 350hp (FB-127) 66-67 belt as listed in their catalog since my car has no AC or PS.

The belt that came with the car when I bought it is a "GATES" brand. I checked their internet site and the application that I have fits both the 327/350hp and 327/300hp motors. When I tried to put the "correct" Zip belt on it seemed a little too big. I had to pull the alternator all the way to the end of the bracket to tighten the belt and it still seems a little too loose when the engine is running.

Any ideas? How do I know if I have the right size pulleys on the car? Should they be single/double groove?

MC

 

[WayneC]

Here's some thoughts:

Interestingly, Long Island Corvette's catalog shows 2 different configurations... both have the alternator on the driver side, one has an extra idler belt from the crank to the water pump, with an extra groove on those pulleys to accomodate it. Both use the same alternator belt. But, they don't show any configurations at all with the Calif air injection setup, which I think some cars came with.

Belts and pulleys are really a confusing area.

Parts book says the correct water pump pulley is (I think, because I'm frankly not clear on whether the 350hp engine is deemed "Sp. H/Per." or not) 7 1/8 inch od stamped 3770245 and is a double-groove pulley, the second groove used for an idler belt. The other possibility is a single-groove pulley 3905995, no indication as to size or markings.

The alternator belt for both the single and (double) idler-belt setup is listed at 3/8 by 54 inches. The idler belt is 3/8 by 34 & 3/8. I'm not sure how to measure a belt... I don't think you can simply measure the OD, but probably have to use a special belt measuring tool.

Might be easiest to go to your local parts store with your belt and have them measure the old one, and if it's correct (54 inches), finding you a slightly shorter one.

And, another possibility for your adjustment problem is an incorrect alternator bracket.

 

[mcditalia]

Thanks Wayne,

I was thinking about the bracket too. All of my pulleys are single groove. Also, the old belt that I had IS the right application for the 327/350 according to GATES, so shouldn't it match closely to the ZIP repro one if they're both indicated for the same application? Eyeballing the two, the ZIP is slightly longer, not a big difference, but once it's on, the alternator needs to be pulled all the way back and it's still kind of loose! BIG Difference!


MC

 

[WayneC]

Talk to ZIP about that issue. Unfortunately, mailing costs are such these days that small items aren't worth returning. Maybe they can give you a credit on your next order.

 

[mcditalia]

Measuring the zip belt it came to be 54" which should be the correct length according to specs. Now the old Gates belt is about 53", which seems to correspond to the 300hp motor specs. Do the 2 motors share different pulley sizes in order to use the two different belt sizes?

Mc