Improving Alternator Pulley Wrap

[Bill Goddard]

I have read of some problems with the alternator pulley being smaller than the generator pulley and requiring a tighter belt tension. This in turn causes additional load on the water pump causing premature failure of the pump. I have not read of any solution for this except tightening up the belt tension. Has anyone thought about creating an idler design that would increase the pulley wrap around? Or is there another answer?
Thanks Bill G

[1931 flamingo]

Bill: Im sure there are thousands of model A's with alternators that have gone thousands of miles WITHOUT w/pump failure. My own is a 6 volt conversion, with about 1-1 1/2 in play in the belt and once started and "excited" charges just fine.................. JMO
Paul in CT

[BILL WILLIAMSON]

Originally Posted by Bill Goddard

I have read of some problems with the alternator pulley being smaller than the generator pulley and requiring a tighter belt tension. This in turn causes additional load on the water pump causing premature failure of the pump. I have not read of any solution for this except tightening up the belt tension. Has anyone thought about creating an idler design that would increase the pulley wrap around? Or is there another answer?
Thanks Bill G

Bill,
My small pulley alternator worked well, I ran a greasless modern bearing water pump with a 6 blade plastic fan.
Myself, I wouldn't run one with an original type bearing water pump. I don't think they would be durable enough for the long run.
Bill W.

[Benson]

Bill,

I use a notched Truck belt that Gates makes.

A notched belt is good idea on Alternators as it wraps tighter and slips less I think.
Notched belts use a different number system
CarQuest has a Truck and Bus Series made by Gates
Numbers on label are:
TR22425
15A1080
11/16ths by 43-1/8th

[howie123]

I have a question along the same line. I have a NuRex 6volt alternator and a new leakless water pump. I don't have the belt excessively tight but there is always a rattle from that area when the engine is running. I could see a little endplay in the water pump shaft which I eliminated with a split collar place on the shaft in front of the packing nut. This did not help the noise. I am currently running a 4 blade truck fan. Would a new 2 blade fan be more quiet? Any help is always appreciated. Thanks. Howie

[Jim/GA]

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USE THE NOTCHED GATES TRUCK BELT.

That is all!

[1931 flamingo]

Howie: Have you ck'd that 4-blade fan??
Paul in CT

[2manycars]

I use a BX40 belt, with notches in the inside. It conforms better around the small pulley.

[howie123]

I looked the fan over carefully before painting it. It looked fine but that doesn't mean I trust it. I watch the paint for any signs of cracking. I think I will go with a two blade aluminum fan in the near future. Thanks. Howie.

[SLPreston53]

I have run alternators on both my A's for thousands of miles. I run the belts so loose friends tell me the belt is going to come off. Never has! The alternator is just not that hard to spin. And, with such a loose belt, there has never been a problem with WP bearings.

[Bill Goddard]

Thanks Steve, I guess it will be OK especially if I get a notched belt so I won't worry about it. Bill G