In looking at the Ecosound system as ref by Alex, it appears that there is a
low speed bypass above the water, that the baffel unit, which apparently
does the silencing is near the stern of the boat (or perhaps even under a
hull extension). Room is gained by having no mufflers, but in retrofits
that there is still even more exhaust tubing space taken (or more space
taken by dual ecochambers). Apparently in some new installations there is a
molding for an exhaust tube that is at the bottom of the hull (bilge?) and
that would seem to take less room, but that the exhaust is still inserted
into the water well aft--not in the middle of the boat as I understood the
system described by Arlid.
I wonder if these advantages of increased speed and economy would be present
for a trawler speed boat?
.
All of this gets me thinking--I have a rather loud exhaust at running speed
( 148 hp turbo Volvo), with a straight pipe out through the hull extension.
(the swim step is a 34" bolted on extension of the hull, apparently factory
added to increase speed). I have been considering pulling the hull
extension, and glassing it in, instead of bolting it in place. Currently it
is open to the water, with freeing ports that drain water as the boat comes
up to speed. I had considered filling the extension with foam when glassing
it in. However this discussion of an echo supression chamber muffler system
with an underwater exhaust might be applied here. I will E-mail Ecosound
and see what their thoughts are about a retrofit. Currently the exhaust is
half in and half out of the water at rest, as the boat comes to speed the
exhaust clears the water.
Any comments from the list?
Bob Austin
In looking at the Ecosound system as ref by Alex, it appears that there is a
low speed bypass above the water, that the baffel unit, which apparently
does the silencing is near the stern of the boat (or perhaps even under a
hull extension). Room is gained by having no mufflers, but in retrofits
that there is still even more exhaust tubing space taken (or more space
taken by dual ecochambers). Apparently in some new installations there is a
molding for an exhaust tube that is at the bottom of the hull (bilge?) and
that would seem to take less room, but that the exhaust is still inserted
into the water well aft--not in the middle of the boat as I understood the
system described by Arlid.
I wonder if these advantages of increased speed and economy would be present
for a trawler speed boat?
.
All of this gets me thinking--I have a rather loud exhaust at running speed
( 148 hp turbo Volvo), with a straight pipe out through the hull extension.
(the swim step is a 34" bolted on extension of the hull, apparently factory
added to increase speed). I have been considering pulling the hull
extension, and glassing it in, instead of bolting it in place. Currently it
is open to the water, with freeing ports that drain water as the boat comes
up to speed. I had considered filling the extension with foam when glassing
it in. However this discussion of an echo supression chamber muffler system
with an underwater exhaust might be applied here. I will E-mail Ecosound
and see what their thoughts are about a retrofit. Currently the exhaust is
half in and half out of the water at rest, as the boat comes to speed the
exhaust clears the water.
Any comments from the list?
Bob Austin
