In browsing around the Air Age office we stumbled on a set of highly detailed drawings for the 150 hp Hispano-Suisa V-8 engine that replaced the 90 hp OX-5 engine in the JN-4 Jenny. A great restored example of the aircraft is in this issues Gallery but these Wylam drawings are so detailed the more determined amongst you could build your own engine from them.
Hispano V-8: Free online drawings
Thanks for providing these drawings.