Muffer vs Waterlock - What do I need (pics included)

[Enyar]

Contrary to popular belief the muffler from my Beneteau First 42 is removeable without pulling the engine or cutting an access hatch in a bulkhead. The issue I am having now is the existing stainless muffler is incredibly narrow and I can't find a replacement for it. It's only 4.75" wide and I don't have that much more space between the bulkhead and the fuel tank where it sits. Additionally I don't know if I need a "water lock" or just a muffler. The existing is just a rectangle with a 2"/ 51mm inlet that goes to the rectangle chamber. The exit is 2"/ 51mm and its a 45* elbow that picks up at the bottom of the chamber and exits to the back. Is that a waterlock or just a muffler?

[rslifkin]

Based on your description it's a water lift muffler (which some brands call a waterlock). If you need one in a custom size the basic design principle is fairly simple. I'd consider buying some fiberglass exhaust tubing for the inlet, outlet, and pickup tube and then building a fiberglass muffler to fit the available space. Larger and more water capacity is fine, but I wouldn't go any smaller than the original design. A larger unit may be a little quieter as well.

[Wotname]

Your original was probably custom made. A replacement will also need to be custom made.

What is the main concern with the original one? The pitting shown in the pictures or something else?

If it is only the pitting and if there is enough room, use the original one as 'core' and fibreglass the 4 (or 6) sides and refit.

[NYSail]

Centek makes custom fiberglass systems, plus they have many options of premade. Give them a call….

[Enyar]

Originally Posted by Wotname

Your original was probably custom made. A replacement will also need to be custom made.

What is the main concern with the original one? The pitting shown in the pictures or something else?

If it is only the pitting and if there is enough room, use the original one as 'core' and fibreglass the 4 (or 6) sides and refit.

That's an interesting idea. The bottom is severely pitted and has holes. Is that something people do?

[Enyar]

Originally Posted by NYSail

Centek makes custom fiberglass systems, plus they have many options of premade. Give them a call….

Their customer service has been incredible, I really wish they made something off the shelf for me but the narrowest option is 6"

[DougR]

Even though the drawings show that the exhaust elbow exits the manifold above the water line, it’s close enough that you need a water lift type muffler.

As mentioned in the other thread, make or get someone to make this in fiberglass and forget the idea of covering the original with glass and resin. Too much risk of the box corroding within the glass and causing problems.