I am not using the stock “alternate air door”. This is a feature that let’s you bypass the airfilter and cowl snorkle in the event of an emergency, like having your airfilter coated in ice. You can pull a lever in the cockpit, and air from in the cowl can get into the engine to keep it running. It’s hot dirty air, so it’s not the best for the engine’s power or longevity, but it’s better than an engine that’s not running…
The stock setup works, but you can’t reclose the alt air door without landing, taking the cowl off, and manually re-closing it. I’m building a simple shutter style door out of aluminum that will allow me to both open and close the door in the air. It will give me a troubleshooting option while in the air, without worrying about being stuck with the choice!
I also epoxied in some aluminum tubing that will act as a drain for any water that enters the air box.
After working on that for a while, I bondo’d a piece of foam into the lower cowl snorkle. This will get carved out to provide a mold so I can build a smooth fiberglass transition between the cowl snorkle and the filtered air box.