Filtered Air Box

The filtered air box (FAB) attaches to the air intake on the bottom of the engine.  It basically directs the air from the cowl inlet, through a filter, and up into the engine.  It also has an “alternate air” door inside the filter, which is opened if something (such as a bird) clogs the main inlet or filter.

Here I am testing the fit of the top of the box.

Here’s what the box itself looks like.

The bottom portion is fiberglass.  The filter is slightly compressed between the fiberglass bottom and aluminum top to create a seal.  Note the cutout in the box (closest to the camera)–this is for the mixture control arm, which would otherwise interfere.

After the whole thing is assembled, we needed to create a tunnel in the cowl to connect the cowl inlet to the air box.  This needs to be aligned pretty well, so the instructions call for attaching a foam block to the inlet and the cowl to be put back on.  We then used a hacksaw blade to cut a tunnel in the foam block.  Here’s that process in progress.

When that was complete, we laid a layer of fiberglass in the inside.  That’s curing now.