Mod II Automotive Stirling Engine Design Description and Performance Projections

The Mod II Stirling engine represents the culmination of activity in the Automotive Stirling Engine (ASE) development program. Incorporating technologies developed throughout the program, the Mod II is a kinematic, single-crankshaft, four-cycle Stirling V engine with an annular regenerator and cooler surrounding each double-acting piston. Its design is based on a unified, one-piece, cast-iron block incorporating crank-case, gas ducts, control lines, and waterjackets. The Mod II also embodies a new piston design, dependent balance scheme, and roller bearings in the crankshaft/connecting rod system.

The Mod II engine is projected to meet ASE program goals of a 30% improvement in fuel consumption compared to the spark-ignition, internal combustion (IC) engine; 1985 emission standards established by the EPA; the ability to be packaged in a current automobile; and a cost competitive with current gasoline and diesel engines.