More about onboard generators

[Jim Lea]

I have looked at some more options, and am now considering the installation
details. My next question is the exhaust. Most units have a wet exhaust.
Can I cut this into my engine exhaust or do I put a new outlet in?

 

[Manlio Laschena]

Followup to msg on Sat, 9 Oct 2004 22:03:08 -0300, "Jim Lea"
<[email protected]> :
(Original msg on bottom)


Absolutely ...new and separate exhaust ! Would be dangerous to do the
other way.
More ... if the generator is a 3000 rpm type (I mean not a low rev
unit) would be better to have a gas-to-water separator and then two
additional exhaust .. to lower the noise.

Ciao
Manlio

I have looked at some more options, and am now considering the installation
details. My next question is the exhaust. Most units have a wet exhaust.
Can I cut this into my engine exhaust or do I put a new outlet in?

Manlio Laschena
s/y Amarose
http://Delphi-Jedi.org

 

[Doug Dotson]

New exhaust for the genset for sure!

Doug
s/v Callista

 

[Jack Erbes]

I have looked at some more options, and am now considering the installation
details. My next question is the exhaust. Most units have a wet exhaust.
Can I cut this into my engine exhaust or do I put a new outlet in?

The other posters have said it is a bad idea but not said why.

The back pressure of the large engine would work against the efficiency
of the smaller generator and when only one of them was running you are
putting a back pressure on the other that can do all sorts of bad things
to engines and even humans.

Jack

 

[Jim Lea]

Two further questions:

If it is an 1800 rpm unit, what if any noise control do I need?

If it is 3600 rpm, where do I find a gas to water separator? Why not just a
(small) waterlock muffler?

 

[Doug Dotson]

Comments below.

Doug
s/v Callista

Two further questions:

If it is an 1800 rpm unit, what if any noise control do I need?

Noise control is nice for your neighbor's sake. Not aware
that dealing with it is any difference for the 1800 vs 3600
rpm units. Internal noise is easier to damp with the 3600 rpm
units.

If it is 3600 rpm, where do I find a gas to water separator?

Pretty much any marine store. Ours came with a water lifter type exhaust
and a water/gas separating muffer to follow the lifter.

Why not just a (small) waterlock muffler?

Typical, but does not damp the glug-glug sound that is so
annoying to others in an anchorage. Just follow it with a
water/gass separating muffler. Installation can be tricky though.
You need a fairly straight run from the output of the muffler to
the overboard dump. Ours has a 90 bend after the muffler and
before the dump. Remixes the water and gas so the glug-glug
comes back somewhat.

 

[Steve]

The back pressure of the large engine would work against the efficiency
of the smaller generator and when only one of them was running you are
putting a back pressure on the other that can do all sorts of bad things
to engines and even humans.

Not mentioned but perhaps implied; The running engine can force the standing
water in the idle engine exhaust sytem back up to the engine exhaust elbow
and possibly into an open exhaust valve.

Steve
s/v Good Intentions