Design Features and Initial Performance Data on an Automotive Steam Engine Part II - Reciprocating Steam Expander - Design Features and Performance

The paper describes the approach taken in the design and fabrication of a 4-cyl in-line trunk piston steam expander suitable for a standard six-passenger automobile. Series poppet admission valving is used with variable cutoff of steam to the expander attained by variable phasing of one camshaft with the aid of a hydraulically operated cam phasing mechanism. A specially formulated lubricant is used which allows expander operation with steam at 1000°F/1000 psig.

Preliminary performance measurements for the expander are presented and results are thought to be good considering the maturity of the system. Improvements to the expander which will result in increased efficiency are discussed.