Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

"Elias Aarnio" wrote in message
...
Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

The newer single wire alternators come in a number of configurations. I
would expect you can get a 60 amp one to fit. Unless you really need the
external voltage control, are you splitting the charge to multiple
batteries? That requirement might lessen your choices some.

On May 20, 2:06*am, Elias Aarnio wrote:
Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

On May 20, 2:06*am, Elias Aarnio wrote:
Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

Elias, what ared you wanting to do?

"Efficient" ? Your lower amp alt. will produce less drag on your
engine, a higher amp takes more engine hp, to pull itself to amke more
power.

The Yanmars have may different types of alternators depending on the
application. if you can come up with a make and alternator number it
would help.

now comes the question of a battery sense terminal for voltage
control? are you wanting a system to adjust the voltage manually?

Waht is your total application and what do you want to do with it?


it helps to know....

On May 20, 9:09*am, Tim wrote:
On May 20, 2:06*am, Elias Aarnio wrote:

Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

Elias, what ared you wanting to do?

"Efficient" ? Your lower amp alt. will produce less drag on your
engine, a higher amp takes more engine hp, to pull itself to amke more
power.

The Yanmars have may different types of alternators depending on the
application. *if you can come up with a make and alternator number it
would help.

now comes the question of a battery sense terminal for voltage
control? are you wanting a system to adjust the voltage manually?

Waht is your total application and what do you want to do with it?

it helps to know....

To be exact a higher amp one does not take more engine power unless it
is called on to deliver more current. I'm assuming the op has a
reason he wants more current like a multiple battery installation. If
not then there is no reason to go to a larger amp one.

Tim wrote:

Elias, what ared you wanting to do?

I want to build a system that will charge the 3 batteries of my sailing
boat in a reasonable time. 1 battery is only used for starting the
engine. 2 other similar batteries are connected parallelly.

As the main purpose is to sail, not use the engine, I want to increase
the output of the alternator and control the charging process by sensing
the voltage on the battery terminals.


"Efficient" ? Your lower amp alt. will produce less drag on your
engine, a higher amp takes more engine hp, to pull itself to amke more
power.

Yep. I still have the power reserve for that.

The Yanmars have may different types of alternators depending on the
application. if you can come up with a make and alternator number it
would help.

I have to check it out.


now comes the question of a battery sense terminal for voltage
control? are you wanting a system to adjust the voltage manually?

Not necessarily. I only use lead batteries so they all have the same
voltage. I still want to compensate the 0,7 volt voltage loss caused by
the battery isolator.

--
EliasA

kirjoitti:

To be exact a higher amp one does not take more engine power unless it
is called on to deliver more current. I'm assuming the op has a
reason he wants more current like a multiple battery installation. If
not then there is no reason to go to a larger amp one.

Bingo. I forgot to say that I have a 60 Ah battery for cranking the
diesel and 2 x 80Ah for other use.

A 35A alternator is not really sufficient for this much batteries to be
charged.

--
EliasA

On May 20, 9:50*am, wrote:
On May 20, 9:09*am, Tim wrote:





On May 20, 2:06*am, Elias Aarnio wrote:

Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.

--
EliasA

Elias, what ared you wanting to do?

"Efficient" ? Your lower amp alt. will produce less drag on your
engine, a higher amp takes more engine hp, to pull itself to amke more
power.

The Yanmars have may different types of alternators depending on the
application. *if you can come up with a make and alternator number it
would help.

now comes the question of a battery sense terminal for voltage
control? are you wanting a system to adjust the voltage manually?

What is your total application and what do you want to do with it?

it helps to know....

To be exact a higher amp one does not take more engine power unless it
is called on to deliver more current. *I'm assuming the op has a
reason he wants more current like a multiple battery installation. *If
not then there is no reason to go to a larger amp one.- Hide quoted text -

- Show quoted text -

Well, actually a higher amp unit will pull more on an initial start up
or with low batterie[s], but will offer a higher recovery rate to
charge the batterie[s] quicker.Then there's the options that one adds
to draw more power than the 30/40 amp. the more energy the alternator
makes, the more energy the alternator takes.
But thinking back to the 70's a '76 chevy pick up truck that was bare
bones with only a heater and lights, the truck was only equipped with
a 37a unit. If you had air it had a 55a.. My '76 caddie sedan deville
had all the butt-wipe including rear defroster and had a stock 65a
delco.

so unless theres more to this thread than when I'm typing this, I
don't know what the OP is trying to achieve.

On Wed, 21 May 2008 00:00:43 +0300, Elias Aarnio
wrote:

kirjoitti:

To be exact a higher amp one does not take more engine power unless it
is called on to deliver more current. I'm assuming the op has a
reason he wants more current like a multiple battery installation. If
not then there is no reason to go to a larger amp one.

Bingo. I forgot to say that I have a 60 Ah battery for cranking the
diesel and 2 x 80Ah for other use.

A 35A alternator is not really sufficient for this much batteries to be
charged.

If you charge at fifteen per cent of capacity per hour, it will take
33 amps. Cutting it too fine with a 35 amp alternator. The 20 hr rate
is 11 amps. It is sufficient unless you want to abuse them by charging
them too fast.

Casady

Elias Aarnio wrote in news:4832788c$0$2661$9b536df3
@news.fv.fi:

Hi,

I am looking for a more efficient alternator for an old Yanmar 1GM
marine diesel. The original is 35 amp and I want to have something
between 50 and 60 amps. There is a bunch of webshops selling
replacements but they are all 35 or 40 amp alternators.

Does anyone happen to know a suitable replacement, a car alternator for
example? The best solution would be an alternator that also has the
sense-terminal for voltage control.


Hmm....60 amps x 14.2V = 852 watts divided by 746w/hp = 1.14hp plus a
little loss as heat. I guess it's doable on a 1GM if it isn't loaded up
very much. It might require a prop change to reduce the propulsion load
to power it without overloading the little 1GM.

I've gotten a recent education about alternators when a boating friend
bought a new alternator as he was passing through here. He bought a new
alternator, but soon cooked it by constantly running it at a constant
hard charging level LESS than its rated output.

It seems "car alternators" and "boat alternators" are NOT "POWER
Alternators", but are made to recharge starting batteries quickly before
they have time to overheat! They are NOT rated for 60 amps CONTINUOUS
DUTY. They will put out rated output but will overheat if you keep that
output for any length of time.

I can't help you in Finland, but here is an alternator website many high
power ham radio operators are buying 100% duty cycle alternators from:
http://www.alternatorparts.com/

Notice how these high duty cycle alternators are NOT cheap like regular
car alternators are.....relatively speaking, of course.

http://www.alternatorparts.com/GM%20...%20upgrade.htm
This picture in a vehicle clearly shows the differences. Notice how much
more COOLING FAN and how the dual rectifiers are huge with their big
heatsinks.

The marine models have flame arrestors on them to prevent fume ignition
in boats. There's a fine screen the air goes through, probably lowering
the airflow a bit at the expense of safety.