Continued Baffles and Seals

December 4, 2019 – After I installed the ramps in the top cowl, I git myself caught up with where I should have been. This is in no particular order…

I needed to close the ends of the ramps so air would not escape to the area outside of the baffles. I carved insulation foam to fit the inboard ends of the ramps, then taped them with packing tape and laid up a couple of layers of cloth over those.

I clecoed them and glued (resined?) them in place. They’re not the finest example of fiberglass work, but they are invisible on the airplane.

I cut the left and right side baffles to fit the ramps, then used the paper clip trick again to find the correct final dimension to allow for the seals.

I used manila paper to make templates for the seals around the ramps. These seals fit surprisingly well here…

I installed the inlet seals on the lower cowl. Since the #6 screws blew right through the fiberglass, I used #8 screws instead.

 

In taking the cowlings on and off, I found another problem. Due to my design of the left inlet ramp and the air filter, the cowl interferes with the ramp. The screws for the inlet seals that attach to the cowl hit the very leading edge of the ramp. A side result of this interference is that I got my first baffle crack even without running the engine…  🙁

I just cut off the corner of that ramp using the crack as one of the edges of the cut. I also notched the inlet ramp to fit the attaching nuts for the seal on the lower cowl.

Here’s the end result (hard to get the camera in there):

I was having a hard time trying to figure out the baffle seals around the front (behind the prop spinner). I looked at a friend’s airplane, and because of the closed ends of the upper cowl ramps, he had minimal sealage there. So I just placed short flat pieces of seal that guide the air past the inlet.

Once all of this was done, I decided it was time to permanently install the seals. After all the hassle of fitting everything, this was mindless. In order to keep each baffle separate and removable, I used screws on the side baffles between the forward and aft sections. The seals overlap at that one point. So this way if I have to remove just one baffle, I don’t have to drill out any rivets.

So now I’ll call the baffle seals complete, except for filling any gaps with RTV.

Time 19:21

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