Wet Exhaust run opinions Anti siphon?

[ColdEH]

Hi everyone . Thought I would post this in here as well

Im installing my generator and was wondering if I should put a loop , above the water line in the exhaust right after the water lock muffler.
It is 20 feet to the back of the boat where I have a goosneck and then overboard . Will the water in the hose overwhelm the water lock muffler and get in the engine , 20 feet of hose is a lot of water . Would a loop stop that ? Also can I use an anti-siphon on the exhaust side ?

Regards

[brantleychuck]

Go to the beta marine web site. They have some useful exhaust system diagrams. http://www.betamarinenc.com/index.ph...exhaust-design. You want to get this right. You are right to worry about the water overwhelming the muffler.


Sent from my iPad using Cruisers Sailing Forum

[ColdEH]

Originally Posted by brantleychuck

Go to the beta marine web site. They have some useful exhaust system diagrams. Beta Marine US: Exhaust design. You want to get this right. You are right to worry about the water overwhelming the muffler.


Sent from my iPad using Cruisers Sailing Forum

Thanks, yes, I do want to get this right , the cost of getting it slightly wrong is very high .

My main engine has a loop right at the water lock , then runs under the floor to the aft lazeret were there is a goosneck , so it has two loops . Being a center cockpit , the runs are long . I figure the water lock muffler only get the water from that drop of the first loop and the rest of the water stays between that, and the goosneck.

I will take a look at the beta marine link , thanks

Regards

[Neeltje]

Ideally, you'd want as tall of a hooked dry riser as you can fit coming directly off of the exhaust manifold, with the water injector mounted on the aft end of the hook. Then, you'd have a constant slope of wet exhaust going to a properly sized waterlock situated as close to the thruhull as possible.

Something like this:

[Cheechako]

Calculate the volume of water in that hose prior to the loop and the volume capacity of the water lift. If you are a CC can you go out the side instead?

[Neeltje]

I forgot to mention that this is the setup for my engine, and not the genset behind it, but the principal is the same:

1) Use gravity as much as you can (water does not like to run uphill).
2) Make sure the waterlock is big enough to hold all of the water in the exhaust run.
3) I wouldn't count on an anti-siphon saving my bacon.

Jacques

[ColdEH]

Originally Posted by Cheechako

Calculate the volume of water in that hose prior to the loop and the volume capacity of the water lift. If you are a CC can you go out the side instead?

I was thinking of that as well but only after I have exhausted all the transom options .

I never thought this would be so complicated .

Regards

[ColdEH]

Originally Posted by Neeltje

I forgot to mention that this is the setup for my engine, and not the genset behind it, but the principal is the same:

1) Use gravity as much as you can (water does not like to run uphill).
2) Make sure the waterlock is big enough to hold all of the water in the exhaust run.
3) I wouldn't count on an anti-siphon saving my bacon.

Jacques

I will post a photo tonight when I get back to the boat of the setup in my engine room for the main engine , it works fine with two loops .

Anti-siphon noted

Regards

[Neeltje]

Originally Posted by typhoon

I was thinking of that as well but only after I have exhausted all the transom options .

I never thought this would be so complicated .

Regards

It wasn't, until they started putting inboard motors on sailboats that heel.

Jacques

[jimbunyard]

More information is needed, but another very important thing to remember is exhaust system back pressure. The generator manufacturer lists allowable values. Excessive amounts can lead to things like overheating, reduced output and burnt valves.

Gut instinct is that 20 feet is too long a run, but this might be an instance where strict objectivity is best employed.

I'm with Cheechako, is it possible to go out the side?