The rubber strips were sandwiched between the flanges and a 3/4" wide strip of aluminum on the back. They were installed with about 7/8" of the rubber exposed.
The only thing left to do is to cut some 2" wide strips of rubber sheet and
attach them to the insides of the rounded flanges. These rubber strips
will seal the gap between the front of the cover and filter bracket. They
were installed with aluminum pop rivets:
The rubber strips were sandwiched between the flanges and a 3/4" wide strip
of aluminum on the back. They were installed with about 7/8" of the
rubber exposed.
Here it is with the filter element and holder installed :
To access the 2 screws for the filter holder, you just pull the rubber strips
back.
This takes some time to make and get it right, but I think it's a very elegant way to handle the carb air intake and filter.
Here is the bottom cowl completed:
Since I don't have a split nose bowl, I will use screws and platenuts to attach the bottom cowl to the nose bowl. Removing the bottom cowl was easier than I thought and is a one man operation. I take all of the clecos (future screws) out except along one of the side channels. Then let the bottom cowl swing down and hang on that one side (it actually hangs straight down and doesn't bend like you would think). I then take out the screws on the one side and it's off. Reinstalling it is just the same procedure in reverse.
Next I'll make the engine cowl doors. The same technique to roll and
shape the bottom cowl pieces was used for the doors. It basically involves
rough cutting the piece to shape and then clamping a couple of 1" boards
along the edge that needs to be kept straight, in this case it was the edge
where the hinge will be attached. Here I am putting a roll on one of
the cowl
doors:
Gotta love it . . over 90 degrees in the shop today, getting very sweaty
while building my Bearhawk.
Looking at the nose bowl and firewall, you will see that there is a definite
sharp bend in one particular area of each. The door was held in place
and the sharper bend areas were marked so I would know where to concentrate
most of the bend.
Once I got the initial shaping done, I wanted to create a way to mount the
door in repeatable position before fine tuning the bend and trimming it to
final shape. At this point the door skin was drilled to the hinge.
The hinge was removed from the top cowl piece and positioned along the top
edge of the cowl door piece. It was clamped in the proper position
and drilled every
2":
Make sure when drilling a long hinge like this that it is clamped straight
and that it moves freely without binding.
With the hinge clecoed in place on the door, we can now attach the door to
the top cowl piece and see what kind of fit we have. Here is the initial
fitting:
Starting to fit nicely but needs just a bit more tweaking. At this point the door was removed, rolled a little and replaced several times until I got a good fit. I found that even with my best efforts, I still got a bit of spring-back at the bottom, but that's okay, the camlocks will hold it shut.
Once the door was fitting nicely, it was final trimmed to allow it to fit inside the groove of the nose bowl flange and to allow a 1" overlap at the aft end. It was trimmed for a 2" overlap at the bottom.
The location of the cowl fasteners (Camlocks) was determined and holding
the door down tightly, the holes were drilled and clecoed for now. Here
is the completed cowl door on the pilot's
side:
