Alternator belt Slippage

[mcon12000]

From the pictures provided the belt is too narrow. You need a larger as in wider belt based on the photos.

[captprogreso]

I had the same problem, my alternator was eating my belts, when was without belt it was spinning very well, then in a trip the alt freeze breaking the belt. You wave a bad roller bearing inside the alt that when under stress will not spin freely any more putting a lot of stress and cousing the squealing.

[a64pilot]

Originally Posted by DeepFrz

Try rubbing a bar of soap on the sides of the belt. Just a little.

That stops the squeal as soap is a lubricant, so it makes the slip worse if anything.

[akopac]

Originally Posted by Fiftybucks

akopac - gates green stripe is the best of the gates belts and i plan on trying one but also the Dayco Top Cog... 15405. Westerbeke recommends the Dayco Top Cog. I will replace with slightly shorter belt than the one on it. I will try both to see which belt eliminates the squeal. I will also take a close look at the pulley surfaces for glazing there. I will report back but it may be a few weeks..

I have an old balmar 125amp alternator. I had a custom size shive machined for it for dirt cheap in MX. It puts out at relatively low engine rpm. I also made a shroud to go over the alternator with a 3” hose that has a blower to move air from it over board. I figure if it’s putting out 100-125 amps I can afford a few amps to maintain good operating temperature. Also have stainless turnbuckle belt tension mod. It’s on a Perkins 4108 low line.

[a64pilot]

You May consider running a hose from a cool location to the alternator and maybe even put a shroud around it.
Normal air flow in an engine room from the engine running and if you have a blower fan places the engine room in a very slight vacuum and air is pulled into the engine room. So a hose ought to have air sucked through it and you could direct the cooling air to the backside of the alternator as there are fans both front and back, but the backside is the hottest due to the diodes being there.
Porsche and I believe some Chevrolet’s have alternator cooling shrouds.

[s/v Jedi]

I have a Yanmar 4LH-HTE with a total of three alternators: the standard 80A one on standard belt with FW pump and two Lestec Brute 210 alternators, one at each side of the pto and with a single Napa belt. I get an easy 375A out of the pair without squealing and with less belt dust than the standard belt. I don’t understand it but it’s how it is

[wsmurdoch]

Originally Posted by a64pilot

Porsche and I believe some Chevrolet’s have alternator cooling shrouds.

Camero, Firebird, and BMW.
https://www.topstreetperformance.com...lternator.html
https://shop.advanceautoparts.com/fi...0xi-alternator

[Fiftybucks]

your comments on the ventilation got me thinking about running the engine blower while underway. it would help with the heat buildup downstairs from both the engine, alternator, and the transmission. But in checking the blower, the surveyor said it is sucking air out, not blowing air in... which is the right direction for the blower to push air?
might be a little off topic.

[a64pilot]

Blowers usually pull air out of an engine room, this removes heat from the room and the smells, if it blew air into the engine room, it could cause the heat and smells to be blown into the salon as of course the engine room is not air tight.
So it’s my opinion that the blower ought to suck air out.
Of course the engine itself is an air pump removing quite a bit of air from the room too, so there is air flow to replace the air the engine removes.
I was saying take a hose and direct this air to the backside of the alternator, that should help cooling somewhat, mostly by supplying cool air to the existing alternator fans as opposed to them pulling in hot engine room air.
The alternator fans suck air from each end of the alternator and blow it out of the middle, they aren’t very powerful fans.

[a64pilot]

Originally Posted by wsmurdoch

Camero, Firebird, and BMW.
https://www.topstreetperformance.com...lternator.html
https://shop.advanceautoparts.com/fi...0xi-alternator

Also several models of Porsche’s I believe, this is one
https://www.vertexauto.com/porsche-a...ot-p-7850.aspx

There ought to be something that would fit our alternators?

[rgleason]

Originally Posted by a64pilot

Also several models of Porsche’s I believe, this is one
https://www.vertexauto.com/porsche-a...ot-p-7850.aspx

There ought to be something that would fit our alternators?

This fits on the 98 Series Alternators, but I see nothing for the small case alternators. Looking at my installation on a Yanmar, the back is about as close as you could make it with our small case alt. Yanmar engineers have no concept or understanding about the need for bigger alternators. If you put this cap on it would melt on the manifold!
Air Intake: 12-98-AIR


I've got an idea for a run-around cycle with two small fan coil units and a small pump. One fan coil would be positioned pointed at the back of the alternator and the other would be positioned in the cabin somewhere. The other alternative is to pump water from the domestic tank and back. It would be one of these computer fan coils



https://www.amazon.com/dp/B07KWPJ4K3...v_ov_lig_dp_it


https://www.amazon.com/dp/B00CFDS3JA...v_ov_lig_dp_it

[akopac]

Originally Posted by Fiftybucks

your comments on the ventilation got me thinking about running the engine blower while underway. it would help with the heat buildup downstairs from both the engine, alternator, and the transmission. But in checking the blower, the surveyor said it is sucking air out, not blowing air in... which is the right direction for the blower to push air?
might be a little off topic.

That’s what I do

[akopac]

To get the alternator shives lined up i remove the belt and drop a metal across and in between the shives. If it drop into the shive belt grooves nicely, it’s lined up.
Also I’ve used belt dressing with varying success to stop startup squeal.

[rgleason]

Maybe secure these CPU cooling blocks on the outside of the alternator with thermal paste or perhaps machined aluminum that conforms with the outside of the alt case.
https://www.amazon.com/dp/B011QICQ6U...v_ov_lig_dp_it

They would probably have to be secured with tapped holes and a bracket on top.


The hose would have to be high temp hose and there would be concern about water, so perhaps it would be better to be like a heat pipe, with refrigerant, and there are also fan coils that are set up for that too.

[akopac]

When I made ours I didn’t have access to Ebay. But what the heck

https://www.ebay.com/sch/i.html?_fro...round&_sacat=0