engine box "gasket"

[TimQ]

Re: engine noise reduction.
My engine box has no type of gasket where it sits on the deck. I spoke with a Sundown rep and he said this was a first step in reducing engine noise. The second was to relocate the air intake louvers from under the gunwales to outside of the cockpit. I'll deal with that next.

My first step is to locate a suitable gasket material and source. Recommendations?

[Jeremyvmd]

Im a huge fan of mcmaster as a source. If you give them a call and describe what you need they should be able to guide u pretty well.

[RobS]

..The second was to relocate the air intake louvers from under the gunwales to outside of the cockpit. I'll deal with that next.

IMO the under gunnel mounted vents are an excellent design in that they are 100% protected from the elements. The boat already has too much salty air prone venting.

The engine box gasketing idea could be a waste of time if the numerous deck hatches are not made air tight as well. You could try laying something like properly sized rope around the opening lip and letting the engine box compress down on it to see if that makes a difference before you go shopping and installing.

[Russell]

I agree with Rob's recommendation to not change those vents under the gunwales. In my previous 97 model with the Cummins the sound was loudest at the helm and quite reasonable back in the cockpit where the vents and hatch cover are located. If you look underneath the helm you will see no sound insulation at all, only under the center hatch cover. Plus there was no bulkhead between the engine compartment and the area under the helm seat. I purchased a sound insulation kit and after many hours of work installing it, the difference in sound was negligible. From reading on this site I found that somewhere around year 2000 the sound insulation was improved at the factory. My present boat has sound insulation about 2 inches thick and the 97 had one inch. On the engine hatch cover the sound insulation reaches to the bottom and hits the lip of the opening when the hatch is closed so a gasket would add almost nothing to the sound insulation. One thing that made a huge difference was new engine mounts. The old ones were hard and transmitted vibration to the whole boat. After they were replaced it was like a new boat.