I designed the Brodak Bearcat, which is about 90% the size of my big 60 sized Bearcat. In comparison to the Rabe Bearcat, the Brodak Bearcat is a little smaller (560 squares compared to 585 squares) and is intended for a 40-46 engine. John Brodak build his prototype at under 40 ounces as I recall. With care, most builders will be able to produce a nice one in the mid 40 ounce range. The airfoil is a real lifter, very similar to the Brodak P-40B, which flies well even into the mid 50 ounce range.
All this to say that a radial engine design may be good for an electric as the ample room inside allows a nice amount of options for placement of electric parts, allowing for shifting the CG with the battery placement. For those wanting to play with the electric game, the Brodak Bearcat could be a good start.
Pat Johnston
Boise Design Division
Skunk Works