The Jim Dandy #3

The Jim Dandy #3 is a test into the feasibility of a pressurized gama type Stirling for a small generating unit. Some initial setbacks limited the power output of this designbut after some refinements this engine can now output 500W of shaft power. Using a small permanent magnet DC motor (about 60% efficient) it has produced greater than 250W of electricity! This type of engine could easily be designed for mass production and would be a perfect cabin power source. The normally wasted excess heat could be used to heat water or as a space heater.

A second generation of this engine is planed with emphasis on ease of manufacturing and reliability. All rolling element bearings and a close contact shaft seal will maximize engine life. It will feature a new simplified crank shaft and superior heater and cooler design. This engine could be pressurized with helium for high efficiency or with air for low maintenance. With an expected continuous power output of 1hp this engine should be useful for many power generation applications.

Specifications (approximate):

Displacer Cylinder Bore: 4 inches

Displacer Cylender Stroke: 2 inches

Cold Cylinder Bore: 4 inches

Cold Cylinder Stroke: 2 inches

Configuration: Pressurized Gama

Continuous Power Rating: 250W of Elestricity @ 680RPM or 500W (.67hp!) shaft break power

Pressurization: An engine drivin piston pump and regulator provides 0-60psi of crankcase pressure

Burner: 126 orfice propane type

Lubrication: Splash oiled sealed crankcase

Intended Use: As a small cabin standby generator

Comments: This is a very large displacement pressurized gama for reserch purposes.

The oil acts very strangly after it is pressurized, disolved gas bubbles out of the oil for hours after it has been drained.

Jim Dandy #3 picture 1

Jim Dandy #3 picture 2