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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.
 
Last edited:

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.
 

sharonov

Member II
Bitter victory or sweet defeat?
I thought I would post an update. The problem was solved about half year ago by installing Balmar serpentine belt kit 48-USP-M25. Ordered from PKYS. Bloody expensive but was easy to install and works really well:


20191208_103203.jpg

Initially the new belt was rubbing against that plug that sticks out of the raw water pump (what is it for?) and I had to dremel one side of it. There is enough of hexagon left in it if I ever need to use it.
Also the alternator "ear" was sticking too far out and pushing against the engine cover and had to be sawed off as shown on the next pic. Not the prettiest way to handle it but was expedient at the time.

20191208_170227_cropped.jpg

So far I have been very pleased with the new serpentine belt installation.
 

Tin Kicker

Sustaining Member
Moderator
Nice!
The serpentine belt was the right thing to do. Trying to run more than 80-90 amps is pushing the limit for what a V-belt can handle.
 

sharonov

Member II
About that "easy to install" part, specifically removing the old pulley. I have to admit, Balmar did warn that even though it may be possible to use wrenches, an impact nut driver would be better. Well, in may experience only the second part of the warning is correct. I was not able to remove the pulley with two large wrenches but a puny Dewalt impact driver (not even the real nut driver) made short work of it. Was an eye opener how well these things work.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
Allow me to allow that I have had two 100-amp Balmars with the original belt system and no problems at all. This is a widely reported result. If necessary, the Balmar can be detuned to fewer amps (less strain on the belt/pulleys). Or a switch can be rigged so that the alternator isn't engaged until the engine reaches cruising rpms (slippage is most likely at startup, esp. if the batteries are depleted. Each 25 amps of alternator output requires one horsepower, or at least that is a popular stated average).

No question the serpentine belt is elegant, but many of us go without.
 

sharonov

Member II
Allow me to allow that I have had two 100-amp Balmars with the original belt system and no problems at all. This is a widely reported result.
...
No question the serpentine belt is elegant, but many of us go without.
Absolutely, no question about it. That is why I could not decide if I should celebrate the victory or pull hair in frustration and tell myself that a better man would have made that V-belt work.
I suspect the bracket was bent a bit and pulleys were ever so slightly angled out of plane. Mister Big Hammer and I fix that bracket while installing the new pulleys. So, it might have worked with V-belt but now I will never know.
 

kiwisailor

Member III
Blogs Author
Nice setup! I'm surprised you could use the single belt with the Balmar 100A model as I thought it needed surpentine or double belt. I have the Balmar 70A on the single belt and it runs like a champ, a little dust but no more than what I would call normal.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
There is much to this battery business that lies beyond my understanding, but as a practical matter, I've never seen my Balmar 100 put out more than 60 or 70 amps.

I believe this is because I never run the bank below 50 percent charge. In typical recharging from 60 percent to 85 percent, the initial charge quickly begins to decline. In about 45 minutes it has declined to 15 amps output, at which time I stop engine charging (because the last 15 percent is a low rate of charge and inefficient use of fuel.)

Since the strain on the belt is related to the output, it might be a consideration that most owners will never see anything near 100 amps output from a 100 amp alternator. For the record, I have three Group 31 AGM batteries.

I think the stock internal Motorola alternator, rated at 55 amps, generally puts out only about 15 amps. (It isn't able to vary the charge according to battery state the way a "smart" external alternator can). Under normal daysailing use, where the battery is kept up by dock power, a high-output alternator will usually put out no more power than the Motorola.

Please correct any misstatements.
 

Pat C.

Member III
Very nice. I have heard that switching to serpentine belts can help to lower alternator temperatures, didn't know if you have seen such an effect. My 100 amp alternator case runs at around 175F via infrared thermometer, it is down regulated to 80 amps max and usually runs at much lower amps still due to the way I use my boat. My V belt is tensioned well, but not so much as to worry about coolant pump damage. I suppose that even well tensioned v belts slip more than serpentine belts.

A possible additional benefit to consider.
 

Tin Kicker

Sustaining Member
Moderator
There is much to this battery business that lies beyond my understanding, but as a practical matter, I've never seen my Balmar 100 put out more than 60 or 70 amps.

I believe this is because I never run the bank below 50 percent charge. In typical recharging from 60 percent to 85 percent, the initial charge quickly begins to decline. In about 45 minutes it has declined to 15 amps output, at which time I stop engine charging (because the last 15 percent is a low rate of charge and inefficient use of fuel.)

Since the strain on the belt is related to the output, it might be a consideration that most owners will never see anything near 100 amps output from a 100 amp alternator. For the record, I have three Group 31 AGM batteries.

I think the stock internal Motorola alternator, rated at 55 amps, generally puts out only about 15 amps. (It isn't able to vary the charge according to battery state the way a "smart" external alternator can). Under normal daysailing use, where the battery is kept up by dock power, a high-output alternator will usually put out no more power than the Motorola.

Please correct any misstatements.

Mentioning that you've not seen more than 60-70 amps is probably one answer about why your belt hasn't dusted, and using the boat enough to not need to charge more than 50% is another. I suspect that you keep your engine in good shape and belt tension would be a third major factor.

fwiw - Lithium batteries initially suck up every possible amp as fast as they can so an alternator without a regulator that accounts for this can be harder on a belt.
 
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