Studies were conducted using spark-ignited reciprocating engines to evaluate ammonia as an alternate fuel for certain military applications. Conventional engines were found to perform poorly on ammonia. Several practical methods for improving engine performance while burning ammonia are described which include increased spark energy, increased compression ratio, engine supercharging, and hydrogen addition to the fuel. Dissociation of ammonia was investigated as a practical means for supplying hydrogen to an engine. The study indicates that satisfactory engine performance can be obtained while burning ammonia. Auxiliary equipment and controls necessary for vehicular use will require development.