It's been a while. Between being away from home for a bit and starting a new project for work, I haven't had much energy to work on the plane. Hopefully I can get back to it now though. I've done a number of random small items over the last few weeks, but nothing too exciting. I finished up most of the FWF wiring, so I sealed the ends of the pass throughs with fire barrier. then I wrapped them in silicone tape and put the hose clamp on (no picture of the final product).
I received the last few fuel hoses I needed. The recommendation by the fuel flow sensor manufacturer is to mount the sensor in a way that just suspends in with the fuel hoses (with the hoses adel clamped within about 6 inches of the sensor), as opposed to rigidly mounting it on the engine anywhere. I have quite a bit of room on the lower left firewall, so that's where I decided to locate it. The one remaining task I have is to adel clamp the output hose that goes to the throttle body.
The last fuel hose is the one that goes from the firewall fitting to the intake of the mechanical fuel pump. I ordered a 45 degree fitting to go on the firewall side to help the hose clear the engine mount and allow more room for the scat tubing to the cabin heat box (removed in this picture). The one gotcha I discovered was that the fitting on the fuel pump was also a 45 degree fitting, which kind of torqued the hose in a very tight radius and made it rub the engine mount. I ordered a new straight fitting from Aircraft Spruce, only to discover the next morning that I already had a spare straight mount. Oh well, I guess now I'll have another spare that I can forget about. With the straight fitting in place, the hose fit much better, although it's going to make for a very tight route for the cabin heat scat tubing.
Switching gears - It doesn't look like much, but I spent an afternoon prepping the cowl hinges. I drilled large holes in between the rivet holes. It's not absolutely necessary, but it's recommended that in addition to rivets attaching the hinges, that epoxy or proseal is used as well. The addition of an adhesive just gives the rivets some additional support and minimizes the chance that they'll work loose over time. The holes provide space for the adhesive to get some extra grip.
I figured I needed to cut my teeth on something fairly simple to learn a little about fiberglass. I scuffed up the area around the oil door and epoxied/riveted the doublers in place. I already learned some lessons with it - I didn't add quite enough flox to the epoxy, so it was a little runny after clamping/riveting and made more of a mess than it should have. I've heard that the oil door can pucker out a little bit during flight due to the high pressure in the top of the cowl, so I decided to bond on the chunk I had cut out from the cowl to double up the strength of it. With that in place, it's very stiff.
After spending hours and hours looking at the cowl fit and marking it up everywhere to help me remember where I need to thicken it up, extend edges, etc, I needed a more mindless task. Nowadays Van's recommends adding an optional louver on the lower cowl to help with cooling. Apparently the change from the simple front landing gear to the new elastomer type impacts the exit air enough to raise engine temperatures. The louver provides a little more exit air.
I laid out where each louver would go and match drilled them to the lower cowl.
Once the marker holes were drilled, I expanded the holes that will form the sides of each cutout.
Lastly, I cut out the material between each hole. The aluminum piece will be riveted to the inside of the cowl and the aluminum tabs will be bent inward to catch the air.
