Air Intake

The intricacies of air filter and heat box.

Work in Progress: Still need to figure out the enclosure.

The O-360 typically comes with a vertical carburetor. On the XHawk it protrudes slightly through the bottom cowl. Upstream from it, we need an air intake that filters the air and can, at the pilot’s discretion, redirect warm air to the carb.

The main options for the intake are the Bearhawk Aircraft heat box, Aircraft Spruce’s MA4-5 heat box (Part# 08-01630), and the Van’s FAB-360/540. This post is about the BA heat box. At the time it did not come with any instructions and left install details entirely to the builder.

Generally speaking it fits the Patrol even tough it seems to rely on a filter size that is more suitable for a six cylinder engine. This may turn out to be an advantage on dusty dirt strips. Part of the top filter is inside the cowl and needs a fairly aggressive inlet ramp to seal its frame to the cowl skin.

The heat box mounts to the carburetor via four head-drilled bolts (MS20074-04-03). The space to get them in is minimal. Widening the holes a bit may be necessary.