Wayne.B wrote in
:

On Fri, 20 Jul 2007 15:59:50 -0500, Geoff Schultz
wrote:

My plan is to replace the existing mixing elbow with a dry stack.
Basically I'll cut off the big round can and replace it with a 10"
high stainless tube U that will have the raw water entering 1/2 down
the side that connects to the muffler. I'll wrap the whole thing in
insulation to reduce the burn potential and heat.

Does this sound like a reasonable solution to this problem?

Perhaps, but take note of Bruce's comments.

What you describe is not truly a dry stack but more closely resembles
a "riser" in power boat language. A true dry stack has no water entry
at all and usually exits vertically through the deck like a lobster
boat. Many commercial fisherman and some long range trawlers use dry
stacks and keel coolers to totally eliminate raw water cooling and
exhaust issues.

Thanks for the nomenclature edification. I'm certainly not versed in this.
Regardless of what you call it, is this a reasonable solution? Based upon
the previous response, it sounds OK.

-- Geoff

On Sun, 22 Jul 2007 21:01:44 -0500, Geoff Schultz
wrote:

Thanks for the nomenclature edification. I'm certainly not versed in this.
Regardless of what you call it, is this a reasonable solution? Based upon
the previous response, it sounds OK.

Yes, it sounds reasonable with all of the usual caveats about proper
design, construction and installation.

One of the problems with many sailboat engines is that they are
frequently below the waterline which makes cooling water exit very
problematic. There is something called a water lift muffler which is
supposed to alleviate this issue by creating a "one way" valve in the
exhaust flow. My old Cal-34 had one but it eventually malfunctioned
and allowed water ingress in a following sea. Fortunately the Atomic
4 had nine lives and always recovered from such mistreatment but it
was a nuisance at best. Eventually I installed a rubber flapper valve
at the transom exit and that solved the problem.

Wayne.B wrote in
:

On Sun, 22 Jul 2007 21:01:44 -0500, Geoff Schultz
wrote:

Thanks for the nomenclature edification. I'm certainly not versed in
this. Regardless of what you call it, is this a reasonable solution?
Based upon the previous response, it sounds OK.

Yes, it sounds reasonable with all of the usual caveats about proper
design, construction and installation.

One of the problems with many sailboat engines is that they are
frequently below the waterline which makes cooling water exit very
problematic. There is something called a water lift muffler which is
supposed to alleviate this issue by creating a "one way" valve in the
exhaust flow. My old Cal-34 had one but it eventually malfunctioned
and allowed water ingress in a following sea. Fortunately the Atomic
4 had nine lives and always recovered from such mistreatment but it
was a nuisance at best. Eventually I installed a rubber flapper valve
at the transom exit and that solved the problem.

All that I'm doing is replacing the mixing elbow with this riser and all of
the other components are remaining the same. The output of the riser will
go to the water lift muffler. I haven't had issues ingress issues.

-- Geoff