Installing a muffler

BillD

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25 Terry Jason with Cummins 370 power
Hello ALL,

I'll be laying out and installing the exhaust system in the boat over the next couple of weeks. I have a question or two on mounting the muffler under the deck.

The muffler is a Centek Vernatone 5" horizontal muffler. The muffler is about 7" tall, 14 inches oval wide and about 40" long. A muffler this big in a 25 footer does not leave enough height between the keel well and deck to "hang" the muffler.

I'll fab up some type of contoured cradle out of Canacore to support the muffler. I plan on glassing the cradle to the hull.

My question is what to use, if anything, for vibration isolation between the cradle and the muffler? Should I put a layer of neoprene or some type of insulation between the muffler and cradle to "cut down" on exhaust vibration through the hull?

Whatever product used cannot absorb water.

Your experience and opinions.

Thanks, Bill D
 

F/V First Team

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Northern Bay 36 - Modified
Always cradled the mufflers on the ends where the hoses slide on. Slipped a piece of rubber in as a buffer between the two. When the time came to get in there you just unbolt the uprights from your anchor (which is glassed to the hull) and remove them, now you have all the space available to fiddle with your muffler and other exhaust parts.

Alternatively you can make a full-length cradle using some 10" OD pvc, slice a section out as a cup, line that and have your upright running down as a spine on the pvc. Connect in the same fashion to your anchors. Might not give you as much room to work though.

Hope that helps.
 

Sailorgp

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Sisu 26
My 26' Sisu is similar in construction to your boat. I have a 34" x 9" round Centek muffler mounted on a couple cradles fastened between the port side inner & outer stringers. There's some type of rubber lining on the cradles that the muffler sits on. You're on the right track with your thinking/planning
 

plowin

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Just take a piece of soft wall exhaust hose and split it in half length wise, slip it over the muffler and let it rub away. No worries it will work like a champ.
 

Toolate

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Putting any fibeglass tube in there or all hose? Centek lists the wall thickness as .148" which seems thin to me but would be nice to have it drain rather than sit in the low spots.
 

Toolate

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Going to cradle mine at the ends and go pipe from the muffler back I think. Hose from mufflers to engine though since it will be uphill run.
 

morgan1727

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I see a lot of builders putting the green sylomer between the muffler and muffler supports to lessen vibration
 

Beyond Tom's

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You don't need anything for the vibration. I installed a 42 inch muffler and did tge same install. Made two cradles out of plywood. Glassed them to the hull and rested the muffler on top. It's a two stage muffler right? Mine is two stage. When it fills with water it gets heavy. I have absolutely no vibration. You could always cut some muffler hose strips to lay on top of the cradles, but it really isn't nessesary.
 
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