Dry Exhaust

jwalka51

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26' Webber Cove lobster boat.
I going to be re-powering my 26' webber cove lobster boat. Right now I have a gas 350 that is all the way down forward with wet exhaust. I am going to be installing a john deere 4045, and I am going to move it back some to gain cabin space. I plan on having a 30-36" long engine box in the cockpit. I want to go with a dry exhaust so I can get rid of the raw water system " I am also going to keel coolers". Anyway, the turndown coming off the back of the turbo on that motor is on the port side. I would like to run the exhaust pipe straight down into the bilge, aft a foot or so, then break over to the port side of the boat and come up through the deck just aft of my wheelhouse.

At this point in time I would like to state that I am a licensed pipefitter welder with a union book in my pocket, and while I travel the country fixing power plants and oil refineries, i do this type of welded stainless piping all the time. I also own a welding and fabricating co in newport RI. So please no technical advise on how to put the pipe together, because that will just piss me off, lol.

My dilema is that I have been told by some experts " RA Mitchell CO" in New Bedford mass" that I cannot do this because It will start a fire bellow deck. I believe that is bs. I have insulated pipes at work that hold some very high temp stuff, to the point that you could rest your for arm on the pipe and not be burned. Furthermore, I could swear that I have seen other boats with this same type of configuration. This guy at Mitchells is telling me to go straight through the box and then out the roof. Having the engine box is bad enough, nevermind a big ass pipe going through is. I believe that he is just telling me this for liability purpose.

Advice would be great, and pics would be even better. thanks guys.
 

F/V First Team

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What you will need, and no doubt you already know this, is an expansion joint. When you penetrate your deck you should have some type of deck plate to dissipate the heat, and since you don't want any raw water system I would suggest that you simply run engine coolant through it to cool down that junction. And lastly a simple heat shroud on your muffler - sometimes done with stand-offs right on the body and other times against the pilot house.

Aside from that it's straight forward, just wrap it with what you prefer below deck and give the pipework plenty of support. Shouldn't have any issues.
 

jwalka51

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Newport R.I.
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26' Webber Cove lobster boat.
Where can I get one of those water cooled deck flanges??? And about how much are they??? I will be using at least 2-1/2" schedule - 10, maybe 3" schedule - 10. Schedule really does not matter. I am sure that they only make that thing in one particular wall thickness, but do they make it in 2-1/2" or 3" I.P.S. and where can I get one. thanks.
 

F/V First Team

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Just make it up with some flat sock and a section of larger pipe. All you're doing is making a water jacket to protect your deck. Plumb it into your engine coolant system and it will keep your deck from becoming scorched.

Like this one was, the pipe was wrapped with insulation and there was a good 2 inches all around the pipe at the deck connection.

0309121428b.jpg
 

jwalka51

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26' Webber Cove lobster boat.
ok, so that plate looks easy enough to make. I can probably do it in a half day and do a very nice job with it. Under 50$$. as far as below deck goes, does anyone out there have a favorite insulation???
 

traditions

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Kaowool blanket and exhaust wrap,coat with silicone.You can get a blanket made like a Infab.They have a add in the back of commercial fisheries news,they are in Lewiston Me.After having both,I like the wet exhaust better.
 

jwalka51

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26' Webber Cove lobster boat.
why are you guys so in favor of wet??? I want the dry and the keel coolers so that I have so much less to worry about. Sure you end up with a big smokey pipe coming up through your hull, but I think that that is way better than a clogged raw water strainer, a bad impeller,heat exchanger issues, a fire in your ehaust due to raw water not being introduced, or a sinking boat due to a catastrophic exhaust failure. Plus I can due away with all that plumbing that goes along with a raw water cooled system and wet exhaust, that shit is a whole other list of stuff that can go wrong as well as being in the way and cluttered below deck. Also in doing away with the raw water pump, its one less belt or accessory on the front of my engine taking up space and horse power. there will also no longer be a need for exhaust riser, witch = lower engine box, and there is no chance of getting water in my engine due to taking a slug astern in rough seas of just due to other problems that arise with wet exhaust systems.

To summ it up, After much thought, I have decided that the benefits and the worry free functional nature of a dry exhaust system, far out way the impact of that of that smoke stack on my boat. I feel that it is far superior as long as it is engineered well, built properly, and installed correctly. But please any input will be appreciated.
 

googinhater

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Yeah not a fan of keel pipes they have the same problems as heat exchanger but its up to you and drag electrolysis. So go for it and add lots of zink
 

Badlatitude

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After listening to a dry exhaust scream for years on end..... Id rather not. It just mentally wore me out. Towards the end of owning the boat I used to wear ear plugs and then hired a captain because I didnt even want to be near the F'ing boat anymore.
 
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