Water Lift Muffler Setup (Opinions, Suggestions)

[bajazu]

Well after determining that the current exhaust setup was not done correct, including the water lift muffler setup backwards i decided to take everything out and start new. I have two setup's im thinking of, basicly im wondering if how i have it setup in this first picture will work. Dont mind my bad drawnings, and unfortunately due to some space restrictions i am limited to what i can do. But i am open to any opinions and suggestions. In the 1st picture this is a pretty standard setup you will find most places. I had to do a hot pipe section due to the water lift muffler only being about 4" below the engine. So by doing this hot section it will be about 12" below the water injection point, and then it has your standard vented loop. Which is about 16" above water line.



In the second picture i have pretty much the same setup minus a vented loop. I have read alot of "sailing around the world" books and alot of the guys reccomend not using a vented loop due to possibility of faliure. They suggest tapping in the injection point and running a 1/8" hose to inside the cockpit. Yes their will be small stream of water coming out of this hose, but they state its a good way to know water is flowing like it should, and all you have to do is pipe it close to a scupper and it wont make a mess. Then i assume this would be the best siphon break because your not relying on a valve to work properly.



What do you guys think about both setups? Will they both work?

[hanleyclifford]

Both of your system ideas will work; mine is like your plan "A", but I have no vented loop. The notion of a tube coming up to the cockpit and draining into a scuper is intriguing - never heard of it before, but it sounds feasible. I rely on OCD to shut off the raw intake thru hull every time I shut down the engine.

[jhwelch]

When my heat exchanger failed and salt water was coming out of the fill hose that is exactly what I did -- temporarily put the fill hose so it went into a cockpit drain until I was able to get to my destination and arrange for a new heat exchanger to be made.

-jonathan

[ndutton]

bajazu,

For your proposed system to be effective the 1/8" hose should run continuously uphill to the cockpit without sags, traps or kinks. The reason it's there is to allow air into the loop and anything inhibiting the air flow is a negative.

Also be aware it's possible that some exhaust gases may find their way into the cockpit via this tube. The normal backpressure in a waterlift system would have another path. The conventional one-way air valve prevents this (allows air in but nothing out).

[bajazu]

Thanks for all the comments, ndutton, very true in your response, i didn't think about it. But overall both systems essentially do the same thing, and should both work, correct?

[ndutton]

I see no functional problem with the system you described.

So that I understand fully, the motivation to modify is concern over a clogged anti-siphon valve and a side benefit of water flow indication, yes?

[bajazu]

Yes that is correct, I was having a lot of problems with the current exhaust setup, once taking everything apart I found the clogged anti-siphon valve, corroded exhaust piping and the water lift muffler installed backwards. So I decided to re-do the whole thing, just wanted to do it once and not have to worry about it any more.

[Dave Neptune]

A word of caution!

bajazu, in my boat with the engine in the middle and little room for a rise at the manifold I have had many problems with breaking the syphon. I have used a few different "anti-syphon" valves and because I have nowhere high enough to mount it giving it enough draw to open they have stuck on me. If I go longer then there is enough water in the lines to almost fil to the exhaust valves. I tried the open system and ran the 1/8" vent line into a cockpit drain and that worked for a while until the small line plugged up. I now operate the vent manually by opening and closing a 1/8" stainless ball valve. And this I have forgotten on three occasions. The last being just after Christmas when I warmed the beastie to charge the batteries back up and run a jetting test. I went back to the boat to check after much rain here in So Cal on New Years day to find the bilge full of oil from the engine and water running out of the dip stick. The water was just about to the floorbaordswhat a mess.
Keep a close eye on whatever you come up with.
Perhaps the reason I have had such good luck with my 41 year old A-4 is a saltwater bathing schedule.

Dave Neptune

[roadnsky]

...Perhaps the reason I have had such good luck with my 41 year old A-4 is a saltwater bathing schedule.

Funny Dave. Very funny.

[thatch]

"Outside the Box"

After speaking with Dave the other day about another unrelated matter, when he told me about his flooding situation I felt really badly for him. There has been some discussion recently about using solenoid valves to control things like the raw water intake or the fuel shutoff and this sounds like another place where an ignition controled solenoid valve might be a good idea.
Tom
P.S. Dave, The next time it happens call me and at least I'll help you clean up the mess.

[bajazu]

Stupid Question

I know this is probably a stupid question, but if I understand the siphon concept correctly, if I close the raw water intake with say a solenoid valve on the raw water intake, like mentioned from thatch this would not allow the siphon to happen at all regardless of the vented loop or breather, correct?

[hanleyclifford]

That's right. Close off the raw intake and the issue evaporates.

[ndutton]

That's right. Close off the raw intake and the issue evaporates.

Correct, but it also means:

• Putt-putt out of the slip to clear water, raise the sails and stop the engine - close the thru-hull.
• Sail back home, turn upwind to furl the sails, run the engine to maintain steerageway - Oops, open the thru-hull.
• Sailing along in air so light the main is slack and FuhWaap, it starts beating itself to death with the roll of the boat. Enough of this, may as well fire up the iron genny. Open the thru-hull before you do.
• You're motoring along in a narrow waterway, engine dies (ethanol again). In the rush to get out the anchor you forget to close the thru-hull. Now the engine has a bigger problem.
• Leaving a mooring like at Catalina - bow and stern hawsers, slack sand line in between and wand pennant. You accidentally motor over the pennant, wrap the prop and stall the engine. Normal level of excitement ensues. Don't forget to close that thru-hull or there might be an abnormal level of excitement.

I dunno about y'all but the less I have to remember, the better and it seems to be getting worse as the calendar progresses.

[hanleyclifford]

Grief of the Ancient Mariner

That's what you have to look forward to Neil - as we get older the brain gets smaller and the prostate gets bigger. Only a healthy history of OCD will sustain us in these times.

[msmith10]

That's true, Hanley, but I've been working hard training my prostate to replace my brain, consequently no net loss.