I started out today still trying to knock out a few low-hanging-fruit items before pressing on to more serious stuff.

I started out by pulling the peel ply and razor trimming the 4-ply CF edge layup to add more depth to the screw hole on the left front edge of the bottom cowling.  I then re-drilled the hole and countersunk it (pic 1).  And then tested out a CS screw with Tinnerman style washer (pic 2).  All looking good here!

To better assess and determine mounting of the armpit air inlet cooling ramps, I mounted the bottom cowling back onto the bird.  I grabbed these shots of the CS screws and washers “in action.”  Besides a minor bit of sanding on the front edge of the added CF to better transition from strake to cowl, this task of adding CF to finalize the cowl CS screw installs is complete (and thanks again to Dave B. for the motivational push!).

Before I dove into the puzzle that is the air inlet ramps, I wanted to knock out another not-huge task: the creation of screw hardpoints between the GIB headrest and inside D-Deck surface to mount the cover around the GIB headrest.  One reason I wanted to work on this now is that to work on it I obviously have to climb in the back seat and face aft… well, squatting there for decent amounts of time causes my legs to go numb, so I want to break up the tasks in as small of time periods as I can.

I first made up the PVC foam hardpoints inside the gap between GIB headrest and inside D-Deck surface.  I then made #6 platenut assemblies using 1/32″ G10.

I then micro’d the platenuts into the foam before glassing them over with 1 ply of BID. I then peel plied the layups.  Here is a fast forward many hours later where I’ve done a rough razor trim, with peel ply still on, of the tabs.  I know they won’t win any beauty contests (neither will the fuel vent lines that are also being hidden!) as they look now, but I’ll clean them up before I install them.

I’ll also note that these are simply the first batch.  I plan on doing a batch of these every day or two to get them in place to secure the GIB headrest surrounding gap cover.

While the above tabs cured, I then did a deep dive on assessing how and where my armpit internal ramps needed installed.  I looked at a bunch of pics of Mike Melvill’s configuration, then accounted for my cold air induction pipes that Melvill did not have. It was getting later in the evening and I wanted to wait until tomorrow before I started glassing these things in… to do a final once over of my notes (I’m certain I’ll need to mod them later on, but looking for best optimization from the start).

Here we have the right side inlet inboard wall. I was pleased that the inboard walls didn’t hinder or hamper my installing the bottom cowl.  Also, note the ramp position markings on the wall side… one forward and one immediately aft of the cold air induction pipe.

After spending well over an hour looking at Melvill references and my own notes, and then doing a bit of research, I closed up shop and headed into the house.  I texted the one other person I know using Melvill CF cowlings with air cooling: Dave Anderson.  I was curious if he used Melvill’s templates as a guide or if he improvised, since clearly after a few years now he must have worked the kinks out.  Not surprisingly he did use Melvill’s templates but had a half-dozen round of tweaks to dial in his cooling (as did Dick Rutan using the same cowling).

With a page of notes in hand I called it a night.  Tomorrow morning I’ll be heading to a local EAA chapter meeting (a first for me in NC) and then I plan to get back onto the inlet ramp installs.