I have been thinking about how I want to try and flow the air through my Sam James "Rotary Cowling" and I am wondering what you all thought about the possibility of creating some "bypass" air to help accelerate the airflow out of the engine before it re-enters the airflow along the belly of the aircraft. 

 

I also was wondering if there might be some advantage during ground operations and climb out if I install some kind of door as seen in the diagram...

 

Doug Lomheim

RV-9A, FWF...contemplating the placement of stuff...