I was able to get a little accomplished tonight.
Here is a pic of the engine cover before I did anything. The existing insulation was full of gaps and there weren't air pockets, there were air rivers that was distorting the inside shape of the cover.
Gaps in existing insulation
The first thing I did was tape all loose areas and eliminate the air rivers.
Gaps taped and air pockets removed
I then began installing the Dynamat sound deadening sheets
I began on the sides of the engine cover
Here is a pic of the Dynamat Extreme completion. The completion took 2 sheets of the Dynamat Extreme.
After completing this two things became obvious. First when tapping on the side of the engine cover with a knuckle it no longer sounds hollow. It now sounds like hitting solid wood. Second the engine cover now weights about 5 pounds more than when I started. The Dynamat Extreme is some heavy stuff.
After completing the cover I set it over the engine and started the coach. With the installation there was a reduction in sound of 3 db at idle and 4 db at 1750 rpm. That is a 4 and 5 percent reduction respectively and I have not yet installed the hood liner and the engine cover was not secured with screws.
I am going to allow the engine cover to sit for a day or two. I want to ensure the weight of the Dynamat does not pull the existing insulation free and ruin the job.
If everything stays in place I will install the hood liner later this week.