What do we have? Here are a few purpose-built aircraft engines. I've chosen to ignore the auto conversions.
Rotax 912 ULS (80 or 100hp, experimental only, Austria)
http://www.rotax-aircraft-engines.com/desktopdefault.aspx/tabid-62/85_read-69/
Notable: liquid cooled heads, electronic ignition, dual carburetors, and gearbox.
Continental O-200 (100hp, experimental,certified USA/China?)
http://www.genuinecontinental.aero/o-200.html
Notable: Tried and true design, lighter than original O-200

Jabiru 3300 (120hp, experimental only, Australia)
http://www.jabiru.net.au/6%20cylinderbodyFrame-1.htm
Notable: ?
[img]http://www.jabiru.net.au/Engines/6cylinder/6cyc-fine-fin-Jabiru-engine.gif[/img]
ULPower 350i (118hp, experimental only, Belgium)
http://www.ulpower.com/engines/ul350i/index.html
Notable: Fuel injected, FADEC, electronic ignition (no mags or breaker points)

Rotec R2800 (110hp, experimental only, Australia)
http://www.rotecradialengines.com/0RotecR2800/R2800.htm


