Source: 2009 Q4 Beartracks, Mark Scott
I have installed several of Van’s parts in my Bearhawk – battery holder, cooling baffling, and air filter unit. I really like their air filter unit. It has very low losses.
Similar to air cleaner units on older cars with carburetors on top of the engine, air is decelerated from the intake into a circular plenum around a circular K&N filter. The decreased velocity and associated air pressure increase greatly reduces losses through the filter as compared to a standard Bracket filter. The air filter can be cleaned and reused indefinitely. I expect to get a two or three percent power increase.
The unit will not fit within the rectangular sheet metal wedge provided with the kit. So I made a wood mold for a fiberglass scoop fairing. I cut a hole in the lower cowl and installed a flange to mate up with the left and right sides of the scoop. The back of the scoop attaches directly to the cowl. The connection between the scoop and Van’s fiberglass unit is conventional using baffling material.
Van’s air filter unit comes with very good directions and illustrates the connection. I had to make a soft aluminum adapter between the baffling and the air filter unit to enable a proper angular fit between the air filter and the air scoop inlet. I am riveting the scoop onto the lower cowl. I am able to take the lower cowl on and off with no problem. I think it looks pretty good, is probably lighter, and most likely has a little less drag. I expect to be flying late summer 2010 and I’ll report on how it works. I still have the mold. It is available to anyone who would like to use it.
Van’s air filter installation on an IO-540. It also fits O-540’s Aesthetically it fills in well under the nose and does not reach as far aft as the stock wedge fairing.