Bill, I did get the jpeg and I really like the concept. I never saw the original VAM. Ed told me about how it was chopped up to fit Tracy's test engine. I asked what was inside it and he said "nothing."   Originally I can recall some discussion on the other list about putting a valve on the inlet to prevent exhaust gas from going the wrong way when the airplane was not moving. That probably came from a misunderstanding of your concept. I really like the version you posted today. Jerry 

Jerry,

 It is interesting how you find out about things after the fact. (ED if your monitoring please let me know if our info is correct) The entire idea of the VAM concept was to create a venturi to draw the cool air in! The reason for the donut fron section was it doubled as an end cap and an inlet bellmouth for the tube. Without the inside tube I am supprised the thing would draw air at all! I'll send you a close up drawing I sent PL's list off line. When you get your engine running it could be worth a re-try. I am supprised Ed missed the center tube, (if he did), he is a sharp guy and doesn't miss much. The other possibility is that he made it removable and they took it out prior to the test.

Bill Jepson