The Conley Stinger 609, 6.09ci V-8 Engine

Stinger 609 1/4-Scale V-8

The Conley Precision Stinger 609 is a fully functional model engine with a displacement of 6.09 cubic inches (approximately 100cc). It is available in supercharged and normally-aspirated models... the unit pictured is equipped with a supercharger. The supercharged model generates a claimed 9hp at 9,500rpm. The normally-aspirated model comes in at 5hp.

The Stinger is designed for use in model cars, airplanes, and boats. Pretty awesome piece of engineering. Check it out in great detail in the Conley factory tour video embedded below.

Update: An online engineering magazine, DesignNews.com, has an excellent article on the Stinger and the problems that Conley had with seating of the rings to eliminate oil-burning. Apparently scaling down cylinder size with respect to a full-scale automotive engine requires a rethinking of cylinder honing practices. Conley eventually turned to engineers from Sunnen, which makes cylinder honing machinery, for a solution. The Design News article contains an embedded video interview with Gary Conley in which he discusses the machining of the Stinger.