Replacement alternator for Yanmar 1GM diesel?
 

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

Replacement alternator for Yanmar 1GM diesel?
 

"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.

Replacement alternator for Yanmar 1GM diesel?
 

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

Replacement alternator for Yanmar 1GM diesel?
 

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....

Replacement alternator for Yanmar 1GM diesel?
 

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.

Replacement alternator for Yanmar 1GM diesel?
 

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

Replacement alternator for Yanmar 1GM diesel?
 

Replacement alternator for Yanmar 1GM diesel?
 

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.

Replacement alternator for Yanmar 1GM diesel?
 

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

Replacement alternator for Yanmar 1GM diesel?
 

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.

Replacement alternator for Yanmar 1GM diesel?
 

Elias Aarnio wrote in news:48333bfb$0$2669$9b536df3
@news.fv.fi:

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.


The cranking battery recharges in just a few minutes as you never
discharge it unless there's something wrong with the diesel, so it's not
part of the problem.....

160 AH house batteries should be charged at 25% of their amp-hour rating
or 40 Amps to start the recharging cycle from 50% discharge. This
current soon drops off as battery voltage comes up on the regulator
setting. Recharging these house batteries at more than 40A will overheat
them and warp the plates, especially if you have them in the usual
boater's pretty box which acts as an insulator so the poor batteries
can't cool themselves by natural convection, or have them stored in the
hot engine room at 180F next to the dieselbeast. Charging current must
be severely reduced as battery temperature increases due to poor cooling
or operation in a hot environment to prevent soft lead plates from
warping, possibly leading to a cell explosion if those plates touch! If
you ever get a chance to look into a boat where a battery has exploded,
do so and you'll want to get rid of this stupid idea that you're going to
recharge the house batteries in 30 minutes at 500 amps.....a really dumb
idea that just permeates every marina you come to.

I think your problem is not how much current the alternator is capable of
producing, I think your problem is light duty alternator overheating if
the discharged house batteries are going to pull 40A out of it for 5-6
hours before the charge starts tapering off allowing the poor alternator
trying to cool itself in that HOT engineroom all sealed up, COOKING IT.

60A would be a great size, if we need to add a 20A underway power load to
the charging house batteries....60A continuous duty, not a $69 cheap
car/boat alternator. 60A dual rectifier alternator is around $400US,
here in the states.

Go to a Finnish alternator shop where you are and talk to the experts.
Tell them what your constant electrical load is from all the lights and
electronics pulling on the house batteries, a sort of worst case
scenario, out there in the dark on a stormy night with nearly dead house
batteries from leaving the engine off way too long. They'll know how
much alternator you need that will survive this awful loading.....