Balmar alternator belt dust

sharonov

Member II
Need help figuring this one out. Ever since I installed the new Balmar alternator kit 621-VUP-MC-100-SV I am getting a lot of belt dust. Here are a couple of pics after 1.5 hours of motoring:
20190902_164913_compressed.jpg20190902_165018_compressed.jpg

And here is some background info:
  • External regulator belt manager is set to 60%. I have not yet dropped my lithium in and, so anyway, my two flooded will not take more than 40A. High loads should not be an issue.
  • Initially I blamed the dust on a misalignment and, indeed, the alternator pulley was off by 0.16". This was fixed by machining a custom washer and cutting saddle insert down to a correct size. The length of (alternator foot + insert + washer) is just long enough for a friction fit. This did not help. I have not measured angular misalignment but it looks good to the naked eye.
  • The original 3/8" mounting bolt was replaced with M10-1.5x90 as required for Balmar.
  • The Dayco 15400 belt is supposed to be the "best" for this application.
  • Tension was adjusted/tweaked a couple of times with no improvement.

My current suspects are:
  • The pulley or belt is wrong. I believe Balmar single-V pulley is a universal fit for both 3/8" and 1/2" and Dayco is 7/16". Other ppl reported good results with this belt. Maybe I received alternator with a wrong pulley?
  • The belt is a knock-off. Not likely: "ships from and sold by Amazon".

Any advice will be greatly appreciated.
 

footrope

Contributing Partner
Blogs Author
The dust is primarily at the alternator? To me that pulley on the Balmar alternator looks too big - too deep - and/or is the wrong "V" angle for the belt. Alignment is also a big deal, not just for forward and aft location, but the pulleys need to be parallel to each other. A straight edge across the diameters of both pulleys is required to check parallel alignment.

As an aside, when I change belts (I have two) it takes more than an hour and a half to break them in and for the dust to stop. Probably I run 3-4 hours and after that, no dust.

Hope this helps.

Craig
 

sharonov

Member II
The dust is primarily at the alternator?
Yes, the dust is only at the alternator.
To me that pulley on the Balmar alternator looks too big - too deep - and/or is the wrong "V" angle for the belt.
I had the same feeling about that pulley but attributed it to the "universal fit".
Alignment is also a big deal, not just for forward and aft location, but the pulleys need to be parallel to each other. A straight edge across the diameters of both pulleys is required to check parallel alignment.
OK, I will check that. It did not look bad though. Not sure how I would adjust angle if it is off.
As an aside, when I change belts (I have two) it takes more than an hour and a half to break them in and for the dust to stop. Probably I run 3-4 hours and after that, no dust.
Yes, after a few hours the belt felt loose and I had to re-tighten it.
 

sharonov

Member II
Need a favor. Could somebody with Balmar alternator take a pic of the alternator pulley with belt and post it? I would like to rule a wrong pulley out. Thanks.
 

sharonov

Member II
It looks pretty normal to me after an hour or so break-in. (It's OK if the belt rides low in the pulley as long as it reaches the "bottom."_
That was after break-in, clean up, re-tightening and then 1.5hour long motoring. My old original alternator produced virtually zero dust.
As for the "reaching the bottom" - I thought it should be the other way around?

Installed 100A Balmar here:
Thank you. I will have to look at the pics on a large screen to compare. Cannot figure out if it is the same pulley or not on the phone.
 
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Tom Metzger

Sustaining Partner
It looks pretty normal to me after an hour or so break-in. (It's OK if the belt rides low in the pulley as long as it reaches the "bottom."_
In these times touching bottoms can get one in a lot of trouble.

The same goes for V-belts. They must run on their sides, not the bottom of the groove.
 
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