Do we Always Close the Exhaust Valve when Ocean Sailing

[delmarrey]

I don't even has valves on my exhaust. The boat would have to be half sunk to get water back to the motor. The exits are about 10" above the waterline, at the dock.

I have the North Sea system (dual exhaust) with port and stbd exits. The tee in the middle is at deck level so even with the boat at an extreme heal water can only get as high as the draft.

Another advantage is if I'm motor sailing and one exhaust is submerged the other one lets out the fumes so there's no back pressure on the exhaust. I assume this is why single exhausts should go out the transom. But I hate the fumes swirling around behind the boats transom, sometimes coming into the cockpit.

As for the OP, I would put in a push/pull system where it could be actuated from the cockpit or cabin area. I did that with my hydraulic steering lock.

In the picture the upper port is the cockpit drain, lower is the exhaust. as you can tell by the carbon streak behind it.

[leonp]

Originally Posted by engineer_sailor

Maybe another approach is an anti-siphon loop on the exhaust

I would imagine a loop plus an exhaust flap would be more than sufficient

Josh


Sent from my iPhone using Cruisers Sailing Forum

If for some reason the engine does not start and the starter keeps cranking, the cylinders WILL FLOOD with seawater.

If the engine starts with normal cranking, there is no problem.

Tapatalk

[delmarrey]

Originally Posted by leonp

If for some reason the engine does not start and the starter keeps cranking, the cylinders WILL FLOOD with seawater.

If the engine starts with normal cranking, there is no problem.

Tapatalk

Yes! That's why you close your inlet thruhull valve, or disable the raw water pump until it does start normally.

[markpierce]

Always closed the exhaust seacock with the engine off in my father's 30-foot auxiliary sloop. On my diesel motorboat with exhaust port on the side, there is no seacock.

[zeehag]

is why ye have a riser on the manifold system, and there is one on the exhaust system to keep water from back flowing into engine when under way. NO i do NOT close any of my exhaust or intake water for engine ports when sailing, as my boat does not ship water. it is put together properly with proper length and height risers and such. and my exhaust out thru hull is above water line. well above the water line. it remains open at all times. my boat is always ready to leave port, shoould that option be necessary.

[FSMike]

Hi Zee -
Love your new title "extreme blacksheep". LMAO.