Thinking about a serpentine belt conversion

[cardude01]

My little Yanmar 4JH4-HTE has a 110 amp Balmar alternator on it. It has always had belt slippage problems and I’m replacing the belt every three months or so plus dealing with all the belt dust.

The kit I found seems expensive, but maybe it’s worth it? I can buy a lot of belts for $430, but this would make less work in the long run.

My crank pulley has a bit of rust on it that I’ve tried to clean but can’t seem to get smooth. I think that’s helping to eat the belts.

Is a conversion worth it?

https://shop.pkys.com/Balmar-48-YSP-4JH-B-Pulley-Kit-for-Yanmar-4JH4-HTE-TE-DTE_p_6152.html

 

[C lectric]

You have to answer that for yourself of course but a lot of these kits are out there and have done a decent job of getting the alternator to do what it should do.

I don't have one but knew a fellow who did this and it helped. Of course then he ran into the problem of the alternator overheating and shutting down.

I could never convince him to turn down the output via the regulator to not over heat the alternator.

He fixed the problem by getting a much different boat.

If the only thing is the cost of the belts it may not be worth it but if you break a belt in a bad spot you may have a bigger problem. You will also lose the coolant pump leading to an overheat.

There may be belts that will do better such as some high quality Gates industrial TOP COG belts but that is a guess. Some belts do better than the stock ones with the engine.

 

[O C Diver]

I prefer serpentine belts, but those people think a lot of their product, IMO. That said, if you're replacing the belt every 3 months, you need to find a solution to the problem. I would probably bite the bullet and get it done.

Ted

 

[cardude01]

Ha! Yes! Maybe I just need a new boat! [emoji38]

Another reason for wanting to do this is my alternator belt is hard to get to. I have only about 3-4” of room in front of my engine to change the belt. It’s doable obviously because I’ve done it multiple times, but I always burn myself and come out black from the belt dust.

 

[cardude01]

I prefer serpentine belts, but those people think a lot of their product, IMO. That said, if you're replacing the belt every 3 months, you need to find a solution to the problem. I would probably bite the bullet and get it done.

Ted

I thought about just replacing the crank pulley that has the roughness on it, but that would require a puller and I don’t think there is room to do all that the way this stupid engine is setup so close to the bulkhead. Such a dumb design!

Cool thing about that kit is the aluminum pulley just mounts to the crank pulley with some bolts.

https://youtu.be/Yv-gquzbFh8

The OEM crank pulley is over $100, so maybe the serp kit is worth it.

 

[sbman]

You may or may not solve the issue with a conversion kit. A buddy did a serpentine conversion on twin FL120s with a Balmar kit and had problems with both that required custom welding to the bracketry to get everything lined up properly, the kit by itself didn't resolve alignment issues with the alternators.

Serpentine is more sensitive to alignment than v belts. He shredded at least 2 serpentines while he tried various solutions to get it under control. It's hard to say if the alignment issue was present before the conversion or not, but he also upgraded to 200 amp large frame alternators so there were multiple changes at the same time.

Getting your pulley groove cleaned up and making sure the alignment of the alternator is completely correct should solve the issue unless your pulley is so far gone that you need to replace it or have it machined.

 

[sbman]

One suggestion for cleaning up the pulley is to take the belt off and run the engine while you apply a scotchbrite to the groove. Of course you won't want to run it very long without the water pump, but a few 30 seconds runs with cooldowns between and watching the temp should be ok. You could do it with the belt in place, but you run the risk of shredding the scotchbrite all over the place and injury as well of course. You have to be careful in any case of course.

 

[Comodave]

I would check alignment first. Do you have a programmable regulator, if you do you could turn down the output some and see if that helps. If it is a single Vee belt they are usually good up to 100 amps so you are pushing the limits of a single Vee belt.

 

[BigTime]

We put a serpentine kit on our Perkins 4.108 about 3 years ago because of the same issue. The belt hasn't needed adjustment since installation.

 

[CPD]

We upgraded our two Volvo's from dual V-Belts to 10-rib serpentine this past summer (upgraded Alternators from nomimal 50-Amp to actual 140-Amp). While the conversion kit included an easy to install pulley overtop the original crank pulley as you describe, the replacement pulley for the Coolant Pump required removing the cooling pumps from the engines (draining all coolant), remove the old and replace with the new 10-rib pulley in the shop, then reinstall the Pumps and refill coolant. If you press fit the new pulleys with the Coolant pumps remaining installed you will likely drive the shaft back into the engine impacting the free turning of the pulley (friction and accelerated wear). Just another step in the possible conversion process to be aware of.

 

[Marco Flamingo]

Do you already have an external regulator on your alternator? I had some black dust around my Balmer 100A alternator when I bought. I checked the settings on my Balmer ARS-5 regulator and they were just the factory settings. The PO had never taken advantage of the programing possibilities. It was not too complicated to change the settings to my actual cruising requirements. I also put on a $40 temp sensor so that if the alternator works hard enough to get hot the regulator lets is cool off. It has a different charge curve now, less stress on the belt, and no more dust.

 

[High Wire]

I would check alignment first. Do you have a programmable regulator, if you do you could turn down the output some and see if that helps. If it is a single Vee belt they are usually good up to 100 amps so you are pushing the limits of a single Vee belt.

This.
Check the alignment with a straight edge. If the alignment is off you will still chew up belts lightly loaded and properly tensioned.

 

[mvweebles]

110a is a lot to pull off a single v-belt, especially if it only wraps 120 degrees around sheave.

You have an expensive alternator and regulator. Bite the bullet and get a proper serpentine belt kit.

Peter

 

[cardude01]

Do you already have an external regulator on your alternator? I had some black dust around my Balmer 100A alternator when I bought. I checked the settings on my Balmer ARS-5 regulator and they were just the factory settings. The PO had never taken advantage of the programing possibilities. It was not too complicated to change the settings to my actual cruising requirements. I also put on a $40 temp sensor so that if the alternator works hard enough to get hot the regulator lets is cool off. It has a different charge curve now, less stress on the belt, and no more dust.

It has an external regulator. I’ve programmed it before with that little magnet tool, but I need to look at it again. Maybe I have it set too aggressively. Thanks.

 

[cardude01]

110a is a lot to pull off a single v-belt, especially if it only wraps 120 degrees around sheave.

You have an expensive alternator and regulator. Bite the bullet and get a proper serpentine belt kit.

Peter

I’m generally a cheap bastard, but I’m beginning to lean this way.

 

[cardude01]

This.

Check the alignment with a straight edge. If the alignment is off you will still chew up belts lightly loaded and properly tensioned.

How would I check alignment? It’s really hard to see in there!

 

[catalinajack]

I mounted a double belt setup on one of my FL 120s. It has worked out quite well. My crank pulley was already a double so I just needed the Lehman double alternator pulley from Balmar and a water pump pulley. The second unused pulley on the crank was painted and rough. It needed to be cleaned up. I used a Milwaukee battery-powered right-angle die grinder fitted with a wire wheel. Worked like a charm. I just needed to rotate the engine a bit to expose uncleaned sections until all was bright and shiny. There are serpentine kits ( Balmar and a Canadian company) but I was unable to use one because my stabilizer pump is mounted to the crank pulley.

You may or may not solve the issue with a conversion kit. A buddy did a serpentine conversion on twin FL120s with a Balmar kit and had problems with both that required custom welding to the bracketry to get everything lined up properly, the kit by itself didn't resolve alignment issues with the alternators.

Serpentine is more sensitive to alignment than v belts. He shredded at least 2 serpentines while he tried various solutions to get it under control. It's hard to say if the alignment issue was present before the conversion or not, but he also upgraded to 200 amp large frame alternators so there were multiple changes at the same time.

Getting your pulley groove cleaned up and making sure the alignment of the alternator is completely correct should solve the issue unless your pulley is so far gone that you need to replace it or have it machined.

 

[Tator]

I run two (1 on each engine) 150amp alternators on my Lehmans. I usually pull 120 amps each at my cruising rpms for hours to charge my 1100ah bank. I have a single 5/8 Gates Greenstripe cogged belt on each alternator. They do not power anything else. I have now had the same belts on for 14 years and approx. 3300hrs. There is a little bit of dust on the engine frts. I believe proper alignment and tension is the key. Use a straight edge to check alignment and also visually observe how the belts are riding on each pulley. Make sure the belt has the same angle as the pulley and that both pulleys match as far as groove angle, width. If you can access the front enough, a pair of calipers can be handy.

Tator

 

[tiltrider1]

In the auto world, serpentine belts use belt tensioners. There is a reason, exactly why I don't know but one should research it and find out why. It might be simply belt stretch on acceleration but it might be something else.

Those look like some very nice anodized aluminum pulleys. Considering the small number of sales, the greater expense to build over steel pulleys, its not surprising the kit costs in the $400 range.

Is it worth it. That is more of a personal decision. Unfortunately this does not look like a risk free decision.

 

[rslifkin]

I run two (1 on each engine) 150amp alternators on my Lehmans. I usually pull 120 amps each at my cruising rpms for hours to charge my 1100ah bank. I have a single 5/8 Gates Greenstripe cogged belt on each alternator. They do not power anything else. I have now had the same belts on for 14 years and approx. 3300hrs. There is a little bit of dust on the engine frts. I believe proper alignment and tension is the key. Use a straight edge to check alignment and also visually observe how the belts are riding on each pulley. Make sure the belt has the same angle as the pulley and that both pulleys match as far as groove angle, width. If you can access the front enough, a pair of calipers can be handy.

Tator

Those big belts aren't quite as good as a multi V, but they'll certainly transmit more power than the typical 3/8 or 1/2 inch V belts.

 

[Marco Flamingo]

It has an external regulator. I’ve programmed it before with that little magnet tool, but I need to look at it again. Maybe I have it set too aggressively. Thanks.

Check out this web page for how to do it. It really is easier to remove the regulator, take it home, and program on the kitchen table if you have a 12V source. The different parameters keep marching by too fast for me.
Like with my smart phone, I need a 12 year-old kid to supervise me. And print out a couple of copies of the table that shows what you have done. Keeping that in the ship's log then gives you some idea of what to change should you need to change things.

 

[mvweebles]

Those big belts aren't quite as good as a multi V, but they'll certainly transmit more power than the typical 3/8 or 1/2 inch V belts.

Post also states the belt runs the alternators and nothing else. That means there is close to a 180-degree wrap around the sheave which is great compared to most configurations that also run the water pump.

I am in process of modifying my mounts on Perkins 4.236. I have a hydraulic pump for stabilizers and two Balmar alternators - 70a and a 150a. Total of three belts, one of which is the serpentine with 150a alternator.

As someone pointed out, $400 for nicely machined pieces in small production run such as these kits isn't such a bad deal. Because the third pulley, I've had machining expenses on top - its not cheap.

Peter

 

[FF]

V belts come in different quality , try for the better ones,
clean your pulley and tune the V reg down a bit.


Most time is spent charging slowly so the difference between an 80A and100A will add little time to the daily charge.

 

[catalinajack]

If your regulators are accessible on the boat (mine are) simply run a 12-volt supply directly to the regulator. No need to run the engine. Simply remove the 12-volt wire from the harness assembly and plug in your temporary supply wire.

Check out this web page for how to do it. It really is easier to remove the regulator, take it home, and program on the kitchen table if you have a 12V source. The different parameters keep marching by too fast for me.
Like with my smart phone, I need a 12 year-old kid to supervise me. And print out a couple of copies of the table that shows what you have done. Keeping that in the ship's log then gives you some idea of what to change should you need to change things.

 

[sunchaser]

Like Tator, we run cogged belts. They are very long lasting with no belt dust. But our belt does not drive a water pump, only the alternator thus less tension required and alignment straightforward. Gear driven water pumps simplify things a lot.

Dude I'd urge a cogged belt and alignment check/adjustment for starters. Your space limitations would not be any easier with a serpentine setup.

 

[High Wire]

How would I check alignment? It’s really hard to see in there!

I have a 2 foot metal ruler straight edge that I lay on the alternator pulley face to span over to the crankshaft pulley. The crankshaft pulley is the standard to align all other pulleys to. You have to eyeball it some but you can get close enough to see if you have a real problem. Now there are laser alignment tools available. You might be able to borrow or rent one from an auto parts store. I'm trying to find a decent youtube video. The pic below shows a laser setup but a straight edge works the same except I use the pulley face with a v-belt.

 

[cardude01]

I have a 2 foot metal ruler straight edge that I lay on the alternator pulley face to span over to the crankshaft pulley. The crankshaft pulley is the standard to align all other pulleys to. You have to eyeball it some but you can get close enough to see if you have a real problem. Now there are laser alignment tools available. You might be able to borrow or rent one from an auto parts store. I'm trying to find a decent youtube video. The pic below shows a laser setup but a straight edge works the same except I use the pulley face with a v-belt.

Got it. Thanks.

 

[AKDoug]

I would check alignment first. Do you have a programmable regulator, if you do you could turn down the output some and see if that helps. If it is a single Vee belt they are usually good up to 100 amps so you are pushing the limits of a single Vee belt.

Another vote for this! I have a Yanmar 4JH2 and a Balmar 100A alternator, I change the belt once a year just so I never lose one during a season. I initially had a lot of dust after installing the Balmar, and after aligning the pulleys it pretty much just went away. Slippage is always improper belt tension, and the indicator light for the alternator that tells me if it isn't working lets me know my tension is slack.

 

[Nomad Willy]

Haven’t read the whole thread but I’d be looking for some double sheaves. It’s a load issue and a 3V belt x2 should handle the load far better and the sheaves should be less expensive. And there’s redundancy. The serpentine belts require high tension.

 

[jleonard]

You should be running industrial V belts. Sometimes they are called green stripe belts. They are much stronger and last longer.
I had a double V bely pulley mounted to the front pulley for a hydraulic thruster. It used a matched pair of industrial belts. The pair lasted 10 years and was fine when I sold the boat last summer.
I too question the serpentine system without a tensioner. Maybe it works fine, I would just question that.
Best of luck however you decide.