Better Half VW engines are Volkswagen auto engines converted to 1/2 VW aircraft engines according to plans and instructions sold by Leonard Milholland of Brookshire, Texas. Milholland began selling these plans in about 1993 and modified them in 2002 to their current version. His principal idea is that VW engines can be converted most easily and efficiently to 1/2 VW engines without cutting the original crankcase. His first conversions used a single carburetor, but the most recent conversions use dual Mikuni carburetors. Detailed information can be found on the Better Half VW Website. The Better Half VW conversion plans can be used to convert several VW engine models. Most 1/2 VW engines converted in the US are from VW engines with a cylinder bore of 92mm. These engines are the O-56 with a 69mm stroke, the O-63 with a 78mm stroke, the O-67 with an 82mm stroke, and the O-70 with an 86mm stroke. There also a few O-66 conversions which have the same stroke as the O-63, but with an increased cylinder bore of 94mm.
Milholland designed a straightforward, minimal light aircraft called the Legal Eagle beginning in 1998. The Legal Eagle can be built from aircraft plans that Milholland sells to builders wishing to comply with the FAA Part 103 regulations for ultralight aircraft. With the success of the Legal Eagle, Milholland has designed and built a two-place Double Eagle, which can be used as a trainer for the Legal Eagle, although it must be licensed in the FAA Experimental category. The prototype uses an unspecified four-cylinder VW 1835cc conversion.