Air filter retaining ring

When last we saw the air filter, its brackets were fitted but there wasn't anything to hold it in yet. So earlier this week, after doodling various methods for securing the filter, I drove up to Airparts on my lunch break to buy a sheet of 0.040" aluminum. Then I cut out a nine-inch square and bent a lip and a joggle into it. Since I only have a small hand brake and not a real joggling tool or any kind of press, this was harder than I thought.

I put a diagonal bend into the new piece to match the inlet ramp:

Then I bent the excess material at the front end into a 90-degree flange. This was kind of a chore, as I wanted the two flanges at the front to match up exactly, as well as for the joggled lip at the back to fit over the transverse stiffener angle. It took some doing to get it all fitting properly. Once I was finally satisfied with the fit, I match drilled the holes through the filter brackets and inlet ramp, plus two more holes at the front to tie the front flanges together.

To attach the side baffle to the inlet ramp and filter retainer, I used some 0.040" angle. This will be riveted to the side baffle, and then the whole stack of angle / retainer / inlet ramp / filter bracket will be held together with screws and nutplates.

I marked the outlines of the cutout, and rough cut it with the air nibbler:

To cut the hole to the final size, I used the drill press like a mill again, followed by files and various deburring tools.

Still a lot of details to finish up, but now at least I have the air filter mounted in its brackets, and the retaining ring that will hold it in place is mostly built.

By the way, this is what the plans for the inlet air duct and filter look like… xeroxed pencil drawings! The best thing to do is to use them to understand what the end goal is, then put them aside and figure out on your own how to build the parts you need to make things work.