The price of standard aviation engines being a bit more than my wallet can handle is one of the biggest obstacles for me in considering building an aircraft.
One day around the ole' water cooler at work, I was talking to Dave York about the problem when he said to me "What if you could have a 100hp engine for under $6,000?" Turns out that Dave does all the CAD work for William Wynne. William is hands down the foremost authority on Corvair engine conversions for aviation use. It also turns out that $6,000 is way on the high side but about, $2,000 to $3,000 is closer if you do most of the work yourself. William's Shop is just down the road from me, in fact I've done many a touch & go right outside his shop at Massey Ranch Airpark.
My other engine of choice is an AeroConversions, Inc VW kit. This is a NICE kit. It comes with everything you need as a "u-assemble it" package.
Talk about getting the most bang for your buck! I'm getting a Corvair!
Rebuilding and converting the engine for aviation use is underway! Click the Engine link for details and to see progress on my engine.