engine bay fire proof insulation

[99maxum211]

so i had to replace my gas tank with that being said i had to cut the shared wall of the engine bay and AFT. any recommendations as to what insulation i should use inside the engine for noise reduction , heat , fireproof?

[jparsons121]

Density is key. Cheap materials like the foil covered foam from the factory don’t deaden the noise very well. There are products from soundtek and soundproofcow specifically designed for boats that work reasonably well. Each has foam, but are engineered with a high density layer that won’t resonate and therefor help to reduce the noise transmitted thru the walls, hatches, etc.
Next comes the installation. Even the smallest gap will allow sound to penetrate and defeat the qualities of the actual material. This also includes addressing the way things are mounted to the wall. I added rubber isolation mounts to things like the battery charger as they were originally direct mounted to the bulkhead and the solid mounting transmitted the noise directly past the insulation.
Lastly, will be dealing with secondary noise created by the vibration and amplified by certain surfaces. As an example, I put a few strips of dynamat on the enclosure of the water heater to stop it from vibrating.

Maybe more info than you were looking for, but I was disappointed with my initial installation because I was just looking at a cheap replacement for the factory install and I didn’t get any really value from the effort installing the cheap stuff the same way the factory did.

[99maxum211]

I'm going to try second skin audio...ive used it in my truck due to the extreme bass I have and let me tell you that product is spot on. Mind you due to the bass I have I cracked my effin roof of my truck. I've installed 3 layers and not 1 issue

[jparsons121]

That’s good stuff. Not sure of its ability to stand up to ER conditions, so I didn’t have it on the list. Only used it on interior work on cars.