muffler

[Beyond Tom's]

I remember a while back somebody was trying to quiet down their boat. I used sounddown 2 inch foam under my deck of my wheelhouse. I went as far as to double it up using 4 inch spike fasteners. I also installed a 4 ft. 2 stage muffler from centek. MDI45 helped me configure it. Once everything was fit in, I glassed in cradles to support the muffler. It did wonders. Ill include some pics when Im at the boat if anybody is interested.

 

[Toolate]

Definitely interested. Please do.

Exhaust design is a hot topic around here.

 

[Beyond Tom's]

the marina I was at talked to an engineer at centek. I have a 440 HP yanmar. Wanted to have a proffesionals opinion. Didn't know if the bigger muffler would cause problems with back pressure. It worked out great. Probably the best you will get, without doing a water lift muffler. Didn't have the room for that.

 

[BillD]

the marina I was at talked to an engineer at centek. I have a 440 HP yanmar. Wanted to have a proffesionals opinion. Didn't know if the bigger muffler would cause problems with back pressure. It worked out great. Probably the best you will get, without doing a water lift muffler. Didn't have the room for that.

I plan on using a 5" Centek MK II Veratone on the Cummins 6B in the 25 T Jason
AND Soundown, on all 4 sides of the engine box.

 

[Beyond Tom's]

when u get the sounddown make sure you order it with the glue on it already. The second order I got didn't have it. Its just easier to peel and stick than to spray the glue and wait till it sets up.

 

[fishmanfh]

I am interested in this. Kind of funny, but I have called and emailed soundown several times about their mufflers. I have talked with two people on different occasions who have both said they would determine the size muffler needed. Neither one has gotten back with me or will return emails or phone calls. Anyways, going to call Scott Baggat at Centek today and see what he says.

 

[WC1966]

Centek

I spoke w/Centek about my motor and what configuration I was looking for as a replacement muffler several years ago. The engineer did a quick calculation and gave me the model number on the phone. Could not have been more helpful, and then he was when I ask if he could sell and ship the thing, and he did for less that I could find online, of through a friends account at Kellogg Marine. Did right by me.

 

[chortle]

Did you take any db readings before and after or during the installation? I have been working on noise abatement for a Cat 3160 on my old Jarvis Newman 36. I have been doing it one step at a time but no great results yet. I called Soundown before I started, they convinced me that new mufflers would be the biggest bang for the buck, they weren't cheap. I installed them but not much change in the pilothouse noise, the sound quality seemed better and it was quieter behind the boat. Moving forward I see lots more opportunities but thought I would pass on my experience. I still have 95db at full speed running at 14 knots, 2300 rpm on the water. It was 110db before the insulation was installed under the deck. The yard installed 1.5" 1# soundown under the platform but only directly over the engine. Hard mounted front feet on the engine. Fuel tanks on either side of the engine with no sound insulation between or above them other than a partial 3/4" plywood bulkhead between the engine and the tanks. Plan plywood overhead, no foam or vinyl. Lots of places for sound to travel behind the engine under the platform which can then travel over the tanks and vibrate the floor above them. I have now built a 1.5" fir bulkhead between the back of engine and the after section of the platform but have not yet closed all of the gaps. Still pretty loud. Vibration is only noticeable around 850 rpm. I plan to close the gaps and cover the new wall aft of the platform with 2" 2# soundown and replace the 1.5" 1# over the engine with 2" 2# per Soundown recommendation. You mentioned you put and extra layer of 2" 2# over the engine, did you do install the first layer and run the engine and then add the second layer? Big difference?