REFLECTOR: Plenum Attachment

[Chuck Harbert]

Scott, in order to get the 540 inlets to mate up to the non-XL firewall (and 
540 NACA scoops), I had to add a wedge of epoxy to the inlet mounting 
flange, so they are about 1/4" thick and very stiff. I only needed to bolt 
thru each side to have them securely mounted. The airflow through the NACA 
inlets and plenum is not disturbed because it is all blended as it goes 
through the firewall.

But with that said, I'm having some non-serious cooling  problems that I 
think might be solved with vortex generators. Does anybody have the specs on 
the size and position of the VG's that go in front of the NACA scoops? It 
only seems to be a problem in climb. I haven't tested to see what my inlet 
pressure is, but I suspect it isn't full airspeed pressure. I don't have a 
spare airspeed indicator, but maybe I'll go get one so I can test it.

Chuck H



Scott Derrick wrote:

I finally found that picture.  I thought I had seen it.  It was in with
your cowl attachment pictures....

I can see two screws on the port side runner's port side..  The long
upper side doesn't look like it has screws in it?  is that just the
reflection hiding them?  How is that held down?

I was envisioning a similar arrangement but hadn't come up with a clean
way of tightly holding the rubber collar.

What kind of PSI does the plenum see at 180 knots indicated?