I am still in the process of evaluating whether I want a below the waterline exhause outlet or one located above the waterline. I had a discussion with an engineer at Centek Industries, one of the largest manufacturers of marine wet exhaust systems. He made some valid points regarding reasons against locating my exhaust below the waterline.
They performed several studies that sought to measure the noise generated by below waterline exhausts depending on the depth below the waterline. At the depth I was proposing (about 3-4 inches), the sound of the bubbles would overwhelm any muffling provided by the water. In order for some meaningful muffling to exist, my exhaust output should be placed 16 or so inches below the waterline, which is equivalent to the exhaust output on my Volvo-Penta 280 lower unit. Going that far below the waterline is going to result in a loss of horsepower, which I cannot afford.
He suggested an above the waterline exhaust output with a waterlock muffler. The waterlock muffler is capable of reducing the sound by almost 20 decibels! This is the type of unit I was thinking of adding:
The muffler has a top mounted input and output, and will sit right below my riser, with the output goosenecking. They noted this muffler provides zero loss power power, which I find difficult to believe.
I'd like to know what your experience with waterlock mufflers has been like, for those who have them. Do they suppress sound from the exhaust well?
BTW, I'm not concerned about the soot from the Diesel exhaust on my hull. I will wear it proudly!
They performed several studies that sought to measure the noise generated by below waterline exhausts depending on the depth below the waterline. At the depth I was proposing (about 3-4 inches), the sound of the bubbles would overwhelm any muffling provided by the water. In order for some meaningful muffling to exist, my exhaust output should be placed 16 or so inches below the waterline, which is equivalent to the exhaust output on my Volvo-Penta 280 lower unit. Going that far below the waterline is going to result in a loss of horsepower, which I cannot afford.
He suggested an above the waterline exhaust output with a waterlock muffler. The waterlock muffler is capable of reducing the sound by almost 20 decibels! This is the type of unit I was thinking of adding:
The muffler has a top mounted input and output, and will sit right below my riser, with the output goosenecking. They noted this muffler provides zero loss power power, which I find difficult to believe.
I'd like to know what your experience with waterlock mufflers has been like, for those who have them. Do they suppress sound from the exhaust well?
BTW, I'm not concerned about the soot from the Diesel exhaust on my hull. I will wear it proudly!