Posted by Brain Guptil (sailordude@…>)
Alternator Belts
Ladies and Gentlemen
I am running an aftermarket alternator that delivers 110A when cold, using a single belt and the original engine pulleys. I am using Gates XL (Gates Green Stripe XL) series and I make sure that I size them correctly. The belt should fit so that the outer surface should be flush with the top of the pulley groove.
Instilling the belt, I adjust the tension so that the belt can be deflected between 1/8 and 1/4 inch, mid span, I also get over 300 hours belt life. My current engine is a Yanmar 4JH-TE but I have used the same combination on a 3GM30F with the same results.
Remember, the belt does not work from tension so much as, as the belt turns around the pulley, the outer fabrics (which does not stretch) forces the material inside of it to expand since it has less circumference due to less radius. As you bent a belt, the material inside of the outer fabric layer expands laterally, pinching the sides of the pulley.
Try high quality belts first, because overtightning will increase loading and stress leading to bearing failure, water pump and alternator alike.
Brian
Posted by Brien Barnewolt (babarnewolt@…>)
Brian-Do you consider Yanmar OEM belts high quality or are the Gates simply better?BrienOn Nov 11, 2006, at 9:34 AM, Brain Guptil wrote:Alternator BeltsLadies and Gentlemen I am running an aftermarket alternator that delivers 110A when cold, using a single belt and the original engine pulleys. I am using Gates XL (Gates Green Stripe XL) series and I make sure that I size them correctly. The belt should fit so that the outer surface should be flush with the top of the pulley groove. Instilling the belt, I adjust the tension so that the belt can be deflected between 1/8 and 1/4 inch, mid span, I also get over 300 hours belt life. My current engine is a Yanmar 4JH-TE but I have used the same combination on a 3GM30F with the same results. Remember, the belt does not work from tension so much as, as the belt turns around the pulley, the outer fabrics (which does not stretch) forces the material inside of it to expand since it has less circumference due to less radius. As you bent a belt, the material inside of the outer fabric layer expands laterally, pinching the sides of the pulley. Try high quality belts first, because overtightning will increase loading and stress leading to bearing failure, water pump and alternator alike. Brian
Posted by Fargo Rousseau (fargo_r@…>)
Hi Rick:Just found this note on the Freedom Group…Something for you to store away in your knowledge file regarding belts. Since we left Florida I have had slipping results with a NAPA substitute belt (couldn’t buy the real gates near the water) and one Yanmar official replacement (the one we removed together). I know you will want to get at the bottom of this issue. The REAL Gates belt might be the ticket… and proper tension will be important no matter which belt you use. An earlier posting on the Group…about three days ago…mentioned a J C Whitney belt tensioning gage…Will try to find for you…Hope you trip went well… Great working with you… We are actually a bid sad today…but also happy that NARISA is in such loving hands. We’ll keep you posted on ducumentation progress.Best Wishes to you and Jayne.Fargo and NangBrain Guptil <sailordude@…>
wrote: Alternator Belts Ladies and Gentlemen I am running an aftermarket alternator that delivers 110A when cold, using a single belt and the original engine pulleys. I am using Gates XL (Gates Green Stripe
XL) series and I make sure that I size them correctly. The belt should fit so that the outer surface should be flush with the top of the pulley groove. Instilling the belt, I adjust the tension so that the belt can be deflected between 1/8 and 1/4 inch, mid span, I also get over 300 hours belt life. My current engine is a Yanmar 4JH-TE but I have used the same combination on a 3GM30F with the same results. Remember, the belt does not work from tension so much as, as the belt turns around the pulley, the outer fabrics (which does not stretch) forces the material inside of
it to expand since it has less circumference due to less radius. As you bent a belt, the material inside of the outer fabric layer expands laterally, pinching the sides of the pulley. Try high quality belts first, because overtightning will increase loading and stress leading to bearing failure, water pump and alternator alike. Brian
Posted by Michael G Katz (mgkatz@…>)
I have F-38 with Balmar add-on alternator. Although the yard where I took delivery of my boat in 2003 had checked engine and belts before I left, we broke two belts on our initial voyage from Barnegat NJ to Deltaville VA in 9 days! (Both at very inopportune times.) When we got to D’ville we upgraded to Gates heavy duty belt and have had no problem in the 3 years since, although we pay great attention to condition of belt and belt tension.
Michael Katz
----- Original Message -----
From: Fargo Rousseau
To: freedomyachts2003@yahoogroups.com
Sent: Saturday, November 11, 2006 11:01 AM
Subject: RE: [freedomyachts2003] Re: Black dust and “V” belts.
Hi Rick:Just found this note on the Freedom Group…Something for you to store away in your knowledge file regarding belts. Since we left Florida I have had slipping results with a NAPA substitute belt (couldn’t buy the real gates near the water) and one Yanmar official replacement (the one we removed together). I know you will want to get at the bottom of this issue. The REAL Gates belt might be the ticket… and proper tension will be important no matter which belt you use. An earlier posting on the Group…about three days ago…mentioned a J C Whitney belt tensioning gage…Will try to find for you…Hope you trip went well… Great working with you… We are actually a bid sad today…but also happy that NARISA is in such loving hands. We’ll keep you posted on ducumentation progress.Best Wishes to you and Jayne.Fargo and NangBrain Guptil <sailordude@brigup.com> wrote:
Alternator Belts
Ladies and Gentlemen
I am running an aftermarket alternator that delivers 110A when cold, using a single belt and the original engine pulleys. I am using Gates XL (Gates Green Stripe XL) series and I make sure that I size them correctly. The belt should fit so that the outer surface should be flush with the top of the pulley groove.
Instilling the belt, I adjust the tension so that the belt can be deflected between 1/8 and 1/4 inch, mid span, I also get over 300 hours belt life. My current engine is a Yanmar 4JH-TE but I have used the same combination on a 3GM30F with the same results.
Remember, the belt does not work from tension so much as, as the belt turns around the pulley, the outer fabrics (which does not stretch) forces the material inside of it to expand since it has less circumference due to less radius. As you bent a belt, the material inside of the outer fabric layer expands laterally, pinching the sides of the pulley.
Try high quality belts first, because overtightning will increase loading and stress leading to bearing failure, water pump and alternator alike.
Brian
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