In several of the mailing lists of which I partake, there's been discussion
of generators of late, originally about using AC, but migrating to charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending the
rest of our lives in the Caribbean, where there's ample of both. However,
the boat currently (pardon the expression) has a working generator of recent
vintage (under 600 hours). It's got a (Diesel) Kubota engine driving an
Onan 6.5KW 3600 RPM electrical end (along with an alternator on a belt).

Unfortunately, despite its large motor mounts, hush box and muffler, and
located inside an engine room, other than from a fair distance off, outside
the boat, it's enough to drive you (well, me, for sure!) mad with the noise,
and, to a much lesser extent, the vibration. As a result, I refuse to run
it except in emergency conditions, and wouldn't consider running it for more
than a few minutes in an anchorage. FWIW, the exhaust noise outside the
boat is pretty minimal - but the engine noise from inside is fierce.

Has anyone successfully tamed the 3600RPM noise monster? If so, what did
you do? Alternatively (again, please excuse the expression), is anyone
interested in a low-hours 6.5KW generator? It would free up a great deal of
battery space! We're inclined toward wind and solar, but have this
otherwise perfectly good, expensive, piece of gear already installed which,
if we don't have someone buy it for some significant amount of money, is
likely to stay put.

Thanks for any input on how to kill the noise monster...

L8R

Skip and Lydia

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"And then again, when you sit at the helm of your little ship on a
clear night, and gaze at the countless stars overhead, and realize
that you are quite alone on a great, wide sea, it is apt to occur to
you that in the general scheme of things you are merely an
insignificant speck on the surface of the ocean; and are not nearly
so important or as self-sufficient as you thought you were. Which is
an exceedingly wholesome thought, and one that may effect a
permanent change in your deportment that will be greatly appreciated
by your friends." - James S. Pitkin

Running a couple hours a day you should be able to get used to
it. More comments below.

Doug
s/v Callista

"Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail wrote in
message ...
In several of the mailing lists of which I partake, there's been
discussion
of generators of late, originally about using AC, but migrating to
charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending the
rest of our lives in the Caribbean, where there's ample of both. However,
the boat currently (pardon the expression) has a working generator of
recent
vintage (under 600 hours). It's got a (Diesel) Kubota engine driving an
Onan 6.5KW 3600 RPM electrical end (along with an alternator on a belt).

Unfortunately, despite its large motor mounts, hush box and muffler, and
located inside an engine room, other than from a fair distance off,
outside
the boat, it's enough to drive you (well, me, for sure!) mad with the
noise,
and, to a much lesser extent, the vibration. As a result, I refuse to run
it except in emergency conditions, and wouldn't consider running it for
more
than a few minutes in an anchorage. FWIW, the exhaust noise outside the
boat is pretty minimal - but the engine noise from inside is fierce.

Has anyone successfully tamed the 3600RPM noise monster?

Yes. Purrs like a kitten.

If so, what did you do?

Bought the optional sound enclosure and installed the genset in it.

Alternatively (again, please excuse the expression), is anyone
interested in a low-hours 6.5KW generator?

Not after the great sales pitch you just gave

It would free up a great deal of battery space!

Only if you can find a way to charge the beasts!.

We're inclined toward wind and solar, but have this
otherwise perfectly good,

From your description it doesn't sound "perfectly good".

expensive, piece of gear already installed which,
if we don't have someone buy it for some significant amount of money, is
likely to stay put.

Better to keep it, install solar and wind, and use the genset as a backup
when necessary.

Thanks for any input on how to kill the noise monster...

Is a sound enclosure available? If so get it. We have an Entec West
genset and without it the noise would be bad. It is powered by
a Fehrymann 1 lung diesel.

L8R

Skip and Lydia

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"And then again, when you sit at the helm of your little ship on a
clear night, and gaze at the countless stars overhead, and realize
that you are quite alone on a great, wide sea, it is apt to occur to
you that in the general scheme of things you are merely an
insignificant speck on the surface of the ocean; and are not nearly
so important or as self-sufficient as you thought you were. Which is
an exceedingly wholesome thought, and one that may effect a
permanent change in your deportment that will be greatly appreciated
by your friends." - James S. Pitkin

On this or another list 3-4 yrs back there was an excellent discussion
of this topic with one very good extended post. A google of the web (vs
groups) "boat engine noise sound-proof" would include the archives of
several private groups. Sorry, don't recall the source.

Basically:
- block/caulk all air leaks out of noisy area; note connecting bilge
areas, spaces behind ceilings, communicating lockers, utility
penetrations, utility conduits, cracks/spaces at edges of non-structural
bulkheads, etc. All hatches into the noise area need to be tightly
gasketed. This leads to providing combustion air and cooling ventilation
to the engine space from outside.

-stiffen any large surfaces so they resonate less

- install sound deadening on all surfaces of the engine space; there are
material specs to check, but you'll find those somewhere

- isolate the motor and the driven appliance from the boat to prevent
sound and vibration from getting transmitted directly to boat structure;
note hose attachments, fuel lines etc. Nothing should touch anything
(skyhook engine mounts... g)

- keep the mechanicals tuned to reduce vibration

There are clearly compromises involved. The discussion covered some of
these and would be worth looking for.

Rufus

In article ,
"Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail
wrote:

In several of the mailing lists of which I partake, there's been discussion
of generators of late, originally about using AC, but migrating to charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending the
rest of our lives in the Caribbean, where there's ample of both. However,
the boat currently (pardon the expression) has a working generator of recent
vintage (under 600 hours). It's got a (Diesel) Kubota engine driving an
Onan 6.5KW 3600 RPM electrical end (along with an alternator on a belt).

Unfortunately, despite its large motor mounts, hush box and muffler, and
located inside an engine room, other than from a fair distance off, outside
the boat, it's enough to drive you (well, me, for sure!) mad with the noise,
and, to a much lesser extent, the vibration. As a result, I refuse to run
it except in emergency conditions, and wouldn't consider running it for more
than a few minutes in an anchorage. FWIW, the exhaust noise outside the
boat is pretty minimal - but the engine noise from inside is fierce.

Has anyone successfully tamed the 3600RPM noise monster? If so, what did
you do? Alternatively (again, please excuse the expression), is anyone
interested in a low-hours 6.5KW generator? It would free up a great deal of
battery space! We're inclined toward wind and solar, but have this
otherwise perfectly good, expensive, piece of gear already installed which,
if we don't have someone buy it for some significant amount of money, is
likely to stay put.

Thanks for any input on how to kill the noise monster...

L8R

Skip and Lydia

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"And then again, when you sit at the helm of your little ship on a
clear night, and gaze at the countless stars overhead, and realize
that you are quite alone on a great, wide sea, it is apt to occur to
you that in the general scheme of things you are merely an
insignificant speck on the surface of the ocean; and are not nearly
so important or as self-sufficient as you thought you were. Which is
an exceedingly wholesome thought, and one that may effect a
permanent change in your deportment that will be greatly appreciated
by your friends." - James S. Pitkin



News Flash,
What you need is to trash that 3600 Rpm Genend, and get an 1800 Rpm
Genend to replace it. Then reset the Injector pump for 1800 Rpm and
enjoy the quiet that results. diesels that turn 3600 Rpm are near the
limit of their mechanical operational range, anbd are NOISY as Hell.
I have a single cyl Fairbanks/Morse that turns at 1200 rpm and is as
quiet as a mouse in winter.

me

On Fri, 11 Jun 2004 02:50:40 GMT, Me wrote:

What you need is to trash that 3600 Rpm Genend, and get an 1800 Rpm
Genend to replace it.

=======================

Yes. Even with a gas engine 3600 RPM gen sets have a very irritating,
busy sound to them. If you turn up the air conditioning however, you
may be able to drown it out. :-)

That worked on my old boat. Also, get a high capacity charging system
and an inverter to minimize run time.

Fron what I understand, the higher frequency noise of the 3600
RPM gensets is easier to dampen than the lower frequency of the
1800 RPM units. My 3600 RPM unit makes about as much
noise as a window air conditioner.

Doug
s/v Callista

"Me" wrote in message
...
In article ,
"Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail
wrote:

In several of the mailing lists of which I partake, there's been
discussion
of generators of late, originally about using AC, but migrating to
charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending
the
rest of our lives in the Caribbean, where there's ample of both.
However,
the boat currently (pardon the expression) has a working generator of
recent
vintage (under 600 hours). It's got a (Diesel) Kubota engine driving an
Onan 6.5KW 3600 RPM electrical end (along with an alternator on a belt).

Unfortunately, despite its large motor mounts, hush box and muffler, and
located inside an engine room, other than from a fair distance off,
outside
the boat, it's enough to drive you (well, me, for sure!) mad with the
noise,
and, to a much lesser extent, the vibration. As a result, I refuse to
run
it except in emergency conditions, and wouldn't consider running it for
more
than a few minutes in an anchorage. FWIW, the exhaust noise outside the
boat is pretty minimal - but the engine noise from inside is fierce.

Has anyone successfully tamed the 3600RPM noise monster? If so, what
did
you do? Alternatively (again, please excuse the expression), is anyone
interested in a low-hours 6.5KW generator? It would free up a great
deal of
battery space! We're inclined toward wind and solar, but have this
otherwise perfectly good, expensive, piece of gear already installed
which,
if we don't have someone buy it for some significant amount of money, is
likely to stay put.

Thanks for any input on how to kill the noise monster...

L8R

Skip and Lydia

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"And then again, when you sit at the helm of your little ship on a
clear night, and gaze at the countless stars overhead, and realize
that you are quite alone on a great, wide sea, it is apt to occur to
you that in the general scheme of things you are merely an
insignificant speck on the surface of the ocean; and are not nearly
so important or as self-sufficient as you thought you were. Which is
an exceedingly wholesome thought, and one that may effect a
permanent change in your deportment that will be greatly appreciated
by your friends." - James S. Pitkin



News Flash,
What you need is to trash that 3600 Rpm Genend, and get an 1800 Rpm
Genend to replace it. Then reset the Injector pump for 1800 Rpm and
enjoy the quiet that results. diesels that turn 3600 Rpm are near the
limit of their mechanical operational range, anbd are NOISY as Hell.
I have a single cyl Fairbanks/Morse that turns at 1200 rpm and is as
quiet as a mouse in winter.

me

Suggest you buy a sound level meter from Radio Shack for $39 analog or
$49 digital and track down the hot noise spots and sound leaks - and
plug them. The irritation is either transmitted thru air - sound
waves, or solids - vibration. There's no other way. Use very soft
mounts. Or double mounts.

3600 rpm is harder to quiet down than 1800 - but you got what you got.

We cruised for 5 years with a 7.5 KW Onan in our engine room under
center cockpit similar design to yours. It was noisy but worse -
unreliable. I've replaced it with a 6 kw Northern Lights 1800 rpm
genset with no sound shield as I like to visually inspect often. Vast
difference in noise created. The Onan had a very noisy air intake -
check this noise source out carefully on yours - and a 2 cyl clattery
engine.

We had and still have 4 big solar panels - it's tough to find a good
spot for these - we moved them 3 times before finding a least
objectionable home.

We had a wind generator - noisy, vibrating and dangerous and high
maintenance - sold it - would not have one again. No matter who's.
When it's squall time at 3 am and the wind kicks up to 35 kts with
cold driving rain - who wants to go on deck to turn it out of the wind
and secure it. They all sound like a Cessna on the back deck trying to
do a short field takeoff. And they **** off you neighbors.



On Thu, 10 Jun 2004 16:09:40 -0400, "Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail
wrote:

In several of the mailing lists of which I partake, there's been discussion
of generators of late, originally about using AC, but migrating to charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending the
rest of our lives in the Caribbean, where there's ample of both. However,
the boat currently (pardon the expression) has a working generator of recent

On Fri, 11 Jun 2004 10:53:28 -0400, "Doug Dotson"
wrote:
Fron what I understand, the higher frequency noise of the 3600
RPM gensets is easier to dampen than the lower frequency of the
1800 RPM units.

===========================================

That has not been my experience for what its worth. My last boat had
a 3600 RPM gas Kohler with a decent sound shield and water lift
muffler, shock mounted under the rear deck. Inside the cabin with the
A/C on, the noise level was barely noticeable. Outside in the cockpit
however I found it objectionable. Not really ear splitting or
anything, just annoying. It had kind of a frantic over reving quality
to it that I have not noticed in 1800 RPM units.

Not sure what you mean by a "frantic over reving quality"? Sounds
like it wasn;t working properly, perhaps a govenor problem.

Doug
s/v Callista

"Wayne.B" wrote in message
...
On Fri, 11 Jun 2004 10:53:28 -0400, "Doug Dotson"
wrote:
Fron what I understand, the higher frequency noise of the 3600
RPM gensets is easier to dampen than the lower frequency of the
1800 RPM units.

===========================================

That has not been my experience for what its worth. My last boat had
a 3600 RPM gas Kohler with a decent sound shield and water lift
muffler, shock mounted under the rear deck. Inside the cabin with the
A/C on, the noise level was barely noticeable. Outside in the cockpit
however I found it objectionable. Not really ear splitting or
anything, just annoying. It had kind of a frantic over reving quality
to it that I have not noticed in 1800 RPM units.

"Ace-high" wrote in message
...
Suggest you buy a sound level meter from Radio Shack for $39 analog or
$49 digital and track down the hot noise spots and sound leaks - and
plug them. The irritation is either transmitted thru air - sound
waves, or solids - vibration. There's no other way. Use very soft
mounts. Or double mounts.

Good suggestions.

3600 rpm is harder to quiet down than 1800 - but you got what you got.

That's counter to what I have heard from manufactures of both types
of generators, and from my experience with my own 3600 RPM genset
vs a friend's 180 RPM unit.

We cruised for 5 years with a 7.5 KW Onan in our engine room under
center cockpit similar design to yours. It was noisy but worse -
unreliable.

Well, that's consistent with ONAN owners around here.

I've replaced it with a 6 kw Northern Lights 1800 rpm
genset with no sound shield as I like to visually inspect often. Vast
difference in noise created. The Onan had a very noisy air intake -
check this noise source out carefully on yours - and a 2 cyl clattery
engine.

Mine is a 1 cyl, but the air intake is a major source of noise. Mine has
a baffle that softens the noise greatly.

We had and still have 4 big solar panels - it's tough to find a good
spot for these - we moved them 3 times before finding a least
objectionable home.

We are facing the same situation.

We had a wind generator - noisy, vibrating and dangerous and high
maintenance - sold it - would not have one again. No matter who's.

SOunds like you bought an Air Marine. Too bad.

When it's squall time at 3 am and the wind kicks up to 35 kts with
cold driving rain - who wants to go on deck to turn it out of the wind
and secure it. They all sound like a Cessna on the back deck trying to
do a short field takeoff. And they **** off you neighbors.

I just flick a switch from inside the boat to shut the wind generator down.
Better yet, the charge controller senses the high wind situation and shuts
it down automatically until the wind calms down to an acceptable level.
Swinging the mill by hand is both dangerous and archaic.



On Thu, 10 Jun 2004 16:09:40 -0400, "Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail
wrote:

In several of the mailing lists of which I partake, there's been
discussion
of generators of late, originally about using AC, but migrating to
charging,
noise, space and cost considerations and other issues.

As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending
the
rest of our lives in the Caribbean, where there's ample of both.
However,
the boat currently (pardon the expression) has a working generator of
recent