Upgrading from V-belts to Serpentine

saildog

Junior Member
Why not just order the alternator from Balmar with a 3/8 pulley since all of the pulleys on your Universal are sized for 3/8? This should prevent the belts from shredding. You would need a 80- 90 amp alternator that would be sized for the 3/8 belt but the Balmar regulator would keep the charge up to max until you batteries reach 80% and them step the charge down.
 

Tom Metzger

Sustaining Partner
Saildog - The angles are the same on 3/8" and 1/2" belts of this type, so if the 3/8" belt works so will the other. Using a 1/2" belt on a 3/8" pulley causes it to ride a little proud, not a problem. I've been doing it for years.

You can see it in the pic I posted yesterday, Reply#12, upper left corner:

http://www.ericsonyachts.org/infoexchange/showthread.php?t=8317

Using a 3/8" belt in a 1/2" pulley might cause the belt to bottom out which would be a problem. Standard Balmar pulleys are designed for both sizes.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
belts and Serpents

This thread is a few years old, but generating power from small diesels is as necessary as ever.

So, Here we are in a future where Betamarine nowadays (AFAIK) has gone to flat ("serpentine") belts on all of their engines.
My new Beta 25 has one. No 'idler' pulley like a car, and the vendor tells me that due to the short distances on all tensioned sides it does not need it.

I removed the belt briefly and also the crank pulley to change the input pipe for the raw water pump. It seems pretty easy to re-tension it to the factory spec.

BTW, I visited the web site referenced above, and the product description talks about Yanmar engines and Hitachi alternators. I would not risk any money with them without a lot more information first. The title and the narrative below it do not match up.
 
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