See Mike Arnold's AR-5 at http://www.ar-5.com/ for a plane that turns 213mph on 65 hp. There are sacrifices, such as range, but it can be done with careful engineering and construction, no retracts required.
And I do acknowledge that you can't go wrong with a properly rebuilt Continental or Lycoming, although some parts are getting scarce, and therefore very expensive. Still, if I were I starting from scratch that may be where I would go...it would be a tough call. There's a lot to be said for the Corvair's six cylinders and dirt cheap parts (except for that 4340 crank and front bearing). But since I'm thoroughly up to speed on Corvairs, own two complete engines in aircraft form and spare parts (none for sale...call my wife after I'm dead), I'm sticking with what I know and have already bought and paid for! Mark Langford ML at N56ML.com http://www.n56ml.com
