johnhenryford

Nice article and good pictures of the Mod I engine, but a little newsflash - the Mod II was completed by 1986 and overcame most of the limitations people still think exist with Stirling engines. It used Hydrogen as the working gas (small amount, so little safety hazard) and could adjust the pressure in the engine to meet the dynamic power needs for an automobile. It could run on any fuel since it was external combustion and had no need for a muffler or catalytic converter since noise and emissions were so low. They tested it in a 1985 Celebrity and compared to the 4 cyl. internal combustion engine it had higher torque and slightly lower horsepower, could reach 0-60 mph faster by 0.6 seconds, and got better gas mileage by 10 mpg (combined score) with 33/58 miles per gallon for city/highway driving. In the report by NASA they claim it could be manufactured cheaply enough to compete with internal combustion engines. The NASA report: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880002196_1988002196.pdf or here if the first link doesn't work: http://www.mechanicalengineering.net/publications/automotive-stirling-engine.pdf Interesting old video produced by NASA on the same subject: On the other hand, it was a pretty complicated engine and might be easier now to use a Stirling powered generator for an electric hybrid car.