Complex sentence: Most of the Divans were powered by, inline-four Continental engines capable of producing, while others (including both the D-1 "Baby" and D-2 "Delta" prototypes) were fitted with, four-cylinder Hercules industrial engines.
Split into simpler sentences: Most of the Divans were powered by, inline-four Continental engines capable of producing. Others, including both the D-1 "Baby" and D-2 "Delta" prototypes, were instead fitted with, four-cylinder Hercules industrial engines.