Which alternator???

[Mattyb]

Hi guys

So I have a new to me boat and have been working on getting the engine ship shape. Most things have been sorted except one.
The boat came with a Yanmar 2qm20, there is a next step regulator fitted with all the wires fitted but going no where because the alternator has been removed. The po stated that the pulleys didn't line up etc so he never fitted it but I founds hitachi lr135-74 regulator in the forward bunk. I have been playing around with mounting positions and have come up with a way to run it. My problem however after doing some research is that it states that only externally regulated alternators should be used with the regulator. So not sure what this one is doing on board. So I may as well just buy a new alternator to be safer than sorry. My house bank is 400a/hr fllooded batts. Any suggestions?

[djmarchand]

Your post was a little confusing as you seemed to mix up alternators with regulators. But here is some info:

The OEM alternator was made by Hitachi and is internally regulated. These can be modified by an auto electric shop to allow external three step regulators but then you still have a weak alternator with a sophisticated regulator attached.

Buy a high output 100 amp (the most you can safely drive with one belt) alternator from Balmar, Hamilton-Ferris, Hehr, Ample Power. Install it with your ??? regulator.

Or if you don't need fast charging, buy a used Hitachi from a junkyard.

David

[Snore]

Originally Posted by djmarchand

Buy a high output 100 amp (the most you can safely drive with one belt) alternator from Balmar, Hamilton-Ferris, Hehr, Ample Power. Install it with your ??? regulator.
.

David

With all respects, the PO put a 100 amp on the 24hp diesel in my boat. I am seeing wear on the belt after about 60 hours, and for $20 I change it to avoid a failure. When the alternator kicks on one minute after the engine starts, you can hear the RPMs drop. I am currently considering downsizing the alternator back to the OEM output. If one is running a 32year old diesel, why make it work harder than needed?

[bmm32005]

With a Balmar regulator you can adjust the belt loading. I had this problem and adjusted the belt loading to about half.

[Bash]

Hitachi alternators may be great on tractors, but they don't handle the heat of a sailboat's engine room well. Get a Balmar.

[Cheechako]

It depends on what other charging sources you intend to have. Personally, on that small engine I would avoid a 100 amp alternator.... unless the pulleys you have on the engine will accept a 1/2" belt. I put 100 amp ones on my 2 cat engines (3gm30) and both ate belts regularly.
My info is a little dated, but I had a Balmar version 3 regulator and an Ample power next step regulator. The Ample power outperformed the Balmar significantly.
If you have solar etc also, I would consider an Ample Power or other 75 amp alternator. The old Delco Motorola's came up to 100 amps and are great alternators. Often very reasonable on Ebay etc., not sure if any will fit the Yanmar footprint though.

[bobconnie]

Theres so many GM 55 to 100 amp alternators out there that are so cheap and work so well, that they make it easier to take the time to fit them to your engine!! just sayin why spend big boat bucks for something you can get for 1 10th the price and work just as well or better !!!

[Stu Jackson]

Leece Neville makes the alternators for Balmar, at a fraction of the price. Why people keep ranting about Balmar is beyond me.

[Mattyb]

Thanks for the feedback everyone. I have a 200watt panel on order and have a 400 watt wind gen already onboard. It just seems a waste to run the engine without getting a charge out of it. The external regulator that is fitted is called a next step regulator and it specifies to only use an alternator that is externally regulated. Think I will look up all the suggestions and see which have external regulators. Am thinking between 50 and 75 amp

[GordMay]

Originally Posted by Stu Jackson

Leece Neville makes the alternators for Balmar, at a fraction of the price. Why people keep ranting about Balmar is beyond me.

Prestolite / Indiel / Leece-Neville have the best technical support and documentation (web) of any OEM.

➥ Prestolite - Leece Neville

The Prestolite / Leece Neville #A0014740JB-B (4400-4700 series) is a PRIVATE LABEL FOR BALMAR #97-24-DE

ie: 4000 Series Maintenance Manual ➥ http://www.prestolite.com/literature...ice-Manual.pdf

[Maine Sail]

Originally Posted by Stu Jackson

Leece Neville makes the alternators for Balmar, at a fraction of the price. Why people keep ranting about Balmar is beyond me.

Stu,

Balmar is now producing many of the alternators for themselves. They now cast their own cases for many of them. I do find the new 6 series and 7 series, based on the Delco 130D case style, to be excellent alternators with some excellent cooling in a "small case" alt. Leece-Neville also builds good alts but companies like Lestek and Leece-Neville are doing less and less manufacturing for Balmar, if any, these days.

Balmar has not offered the old Motorola case (Leece-Neville 8MR series) alt in a while.. The Leece-Neville 8MR series is still a good alternator if that is what your engine takes..

You don't have to pay Balmar prices but there are only two companies I know of building small case alts in the 130D style and with the dual internal fans they cool extremely well. That case style from either Electromaax or Balmar are my first choice these days when a small case alt needs to pump out high current for extended periods.

[Snore]

Originally Posted by bmm32005

With a Balmar regulator you can adjust the belt loading. I had this problem and adjusted the belt loading to about half.

Could you help me understand this? From what I have seen in the web, you reduce the belt loading by reducing the field.

If you reduce the field on a 100amp alternator by 30%, aren't you basically downgrading it to a 70 amp alternator?

Thanks

Bill

[Sailmonkey]

Originally Posted by Snore

Could you help me understand this? From what I have seen in the web, you reduce the belt loading by reducing the field.

If you reduce the field on a 100amp alternator by 30%, aren't you basically downgrading it to a 70 amp alternator?

Thanks

Bill

You are 100% correct. But with an appropriate regulator you're still dumping 70A for an extended period of time rather than the rapid taper off with an internal regulator.

[Cheechako]

Originally Posted by bobconnie

Theres so many GM 55 to 100 amp alternators out there that are so cheap and work so well, that they make it easier to take the time to fit them to your engine!! just sayin why spend big boat bucks for something you can get for 1 10th the price and work just as well or better !!!

Yep. Bigger bearings than the prestolite etc as I remember too.
For many years Balmar used Prestolite, as did Ample I think based on visual identity. Small frame, lightweight alternators really. Not much heavy duty about them other than what Balmar added like diodes.
Leece-Neville's claim to fame was their huge big frame alternator like used on large trucks.... now that was a true heavy duty alternator! Nowdays, not sure what the Leece Nevill/Prestolite name means really...

[Maine Sail]

Originally Posted by Snore

If you reduce the field on a 100amp alternator by 30%, aren't you basically downgrading it to a 70 amp alternator?

Thanks

Bill

Yes but if your belt can only handle 70A then it can only handle 70A.

There is another benefit though to using either:

A) A larger alt than you need or the belt can handle

B) De-rating an alternator in belt manager

By using a larger alternator than you need and de-rating it in belt manager the alternator, designed for more serious duty, will run cooler and last longer. The belt will also last longer and you'll have less wear, slipping, heat and belt dust.

I very often install larger alternators than the belt can "technically" handle and then de-rate it with belt manager. The alt runs along cooler, no belt dust and the banks get charged. If in the future the owner decides to get a bigger bank or opts for a dual belt or serpentine pulley kit he already has an alternator that can handle it with a simple reprogramming of the regulator.

By running an 80A alt on a 3/8 belt on a bank that can take 100A that alternator will see some serious heat working up against its limit. By installing a 120A alt and de-rating it to 80A the alt will simply last longer, run cooler and be ready for an upgrade when or if the owner decides it is necessary..