I think I've found just what you are looking for:
The RCS 215

215cc (13.1 cubic inch) 5 Cylinder Gas Radial Engine

It weighs in at 11 pounds and can swing a 30x 12 (Menz S) at 5600 rpm!
13.5 HP

It's a beautiful engine and looks like it's worth the $2650. You can see it at:
http://www.rcshowcase.com/rcs215.htm

When you get one, give us a full report.

Ken