Dual Alternators on Yanmar 4JH3E

[Pacey16]

I am looking for the easiest way to fit dual alternators to a yanmar 4JH3E, If I removed the harmonic balancer it would be simple fitting a pulley in its place but would this damage the crankshaft or engine running it without the balancer.
Maybe I could fit a second pulley to the waterpump and drive it off the other side if the bearings in the waterpump were up to it. I know the ideal set up would probably be to mount the 2nd pulley onto the harmonic balancer but thats a lot of machining and mods to make space. Any suggestions.

Thanks, Niven.

[Hud3]

I installed a Balmar 210 amp alternator on a custom mount on my 4JH3BE, in addition to the 100 amp Balmar that was factory installed. I bought a dual track pulley from Yanmar distributor Welcome to Mastry Engine Center for about $70 and installed it myself--simply replaced the single pulley on the flywheel. I talked with the Mastry folks about my plan to make sure there wouldn't be any problems with additional loads on the bearings. A local mechanic fabricated and installed the custom mount for me. Works great!

[Pacey16]

Thanks for reply, so you replaced the single grove pulley with a double grove from Mastry and bolted the harmonic balancer back onto this?

[Hud3]

I don't know what you mean by "harmonic balancer". The original single pulley was bolted onto the face of the flywheel. I simply replaced it with the double from Mastry. Six bolts off and on, and done!

[MarkJ]

Originally Posted by Hud3

Balmar 210 amp alternator... in addition to the 100 amp Balmar !

Holy screamin fan belts Batman! How does the donk go with that?



Mark

[Pacey16]

Hud, sounds like your engine is an earlier model without harmonic balancer, mine is around 2002 vintage.

[Hud3]

Originally Posted by MarkJ

Holy screamin fan belts Batman! How does the donk go with that?



Mark

56 hp, wimpy boy!



Pacey, my engine is a 2001.

[Pacey16]

Hud, On my engine I have a harmonic balancer which looks like a small flywheel and the pulley is between it and the crank, I thought the previous model did not have a balancer which made me wonder if it was absolutely necessary or not. But you would think when an engine doesnt have an airfilter there wouldn't be anything else on it that wasnt imperative?

[Journeyman]

Hud, or others, with similar installations,

Can you help me with alternator selection?

I am in a quandrary evaluating which dual alternators to mount to my new Yanmar 3JH5.

Hud, you seem to have made the only pertinent post in the whole world on this subject, when you said you have both a 100A and a 210A secondary. Can you quantify your "works great" comment?

Questions please:

1) When the batteries are really low (charge acceptance rate is really high) what actual current do you get out of the 210A alternator at fast engine idle of around 1,250 rpm (2,500 rpm alternator) after 15 minutes? 30 minutes?

2) Same questions for the 100A.

I am questioning whether the 210A is a significant improvement over the 100A at low engine RPM. And therefore whether just to get two 100A alternators.

Thank you very much,

Journeyman
San Diego