ORIGINAL: Juice
The discussion here has been very helpful and I even got to learn a few new things.
The green in this new picture is what I plan on doing next... before I try opening up the top of the cowl. The side walls of the baffle used to go up to the middle of the engine. They now go all the way up almost to the top of the cowl. The top/forward edge of this new duct is rounded. This is already done. Now, I am going to round off the top back of the cowl. Last, I am going to use 1/64 ply with epoxy and microballoons to create a lip on the forward edge of the outlet hole.
This should help reduce some of the unwanted high pressure pockets inside the cowl.
Honestly, this is great information in this thread and I appreciate all of you sharing your knowledge.
This is an upper shroud--on my ZDZ160 -- the forward section slides under the returned edge on top of cowl.
th lower section is integrated with the cowl- for ease of removal