Exhaust: Ball Valve

[stillbuilding]

Originally Posted by S/V Alchemy

True indeed, but I am more concerned with the constant "pumping" action of dipping the starboard exhaust aperature below the WL when I'm sailing on port side.

I realize my concerns are essentially minority ones.

Of course not all seas are "following" and a sea regularly hitting the OP's midship might indeed force water back up the exhaust even with a low riser in place. The Vetus water trap might reduce the risk but maybe not eliminate it?

[Tim Schaaf]

On my previous boat, I installed a high loop and a ball valve. My exhaust thru hull was several inches above the waterline, at rest, but my quarter wave came right up to it, underway. I only used the ball valve on a couple of occasions, offshore and in very big seas. When I did this, I would hang the engine key on the valve handle as a memory aid. Everything worked fine, and i had no worries in really rough weather.

Cheers,
Tim

[delmarrey]

Originally Posted by stillbuilding

At the risk of pinching the thread, Del can I ask if the exhaust fumes are a problem with your North Sea arrangement? Your arrangement is what I had planned but even Gerr has mentioned that some owners had had a problem with this exhaust. Just wondering.

My exhausts are fairly far aft and is directed downward. I haven't experienced any fumes except when tied to the dock, on the dock side, when I'm on the dock. But I'm not there long if the motor is running, I'm preparing to shove off.

If I'm sailing and the port or stbd exhaust port is under water, and with the Vetus thruhull fitting, it acts like a siphon and pulls any residual water out.

When I'm motoring slow the fumes just trail aft and away as you can see the carbon trail in the picture. Motoring at hull speed both exhaust ports dip just below the water line, and again the water is siphoned out.

A sea hitting on the quarter might go up into the exhaust port but would most likely go out the other side before it could get to the top of the riser, which is about 18" above the motor exhaust riser and 24" above the Vetus wetlift.

As well my "T" in the middle is actually a "Y" and about 12" higher then the thruhulls, due to the shape of the aft section, which means the water would have to go up hill to get to the center.

BTW the upper thruhull fitting in the picture is the cockpit stbd drain, and the two holes aft are bilge pump outlets, which also have a riser just before the exit (incase there is curiosity).

I have an older fitting w/o the butterfly.
.