It is the Able Experimental Aircraft Engine Co.” that converted a car boxer engine from the Volkswagen brand into an aero engine for lightweight aircrafts.

The Able "2275" with reduction gives 105 hp at 3800 rpm. With the "2500" engine two powers are obtained: 85 hp at 2700 rpm directly coupled to the crankshaft and 180 hp at 4500 rpm with reduction gear that could be of various ratios.

They built a two cylinder "half VW" taking profit of the brand's parts.  And the experimental 8-cylinder engine was the result of coupling two VW's by means of a reducing gear with belts driving the coaxial contra-rotating propellers to give 360 hp at 4500 rpm.