Help regarding Hercules Identification

I am working on a history of the first jeep built by the American Bantam Car company in Butler PA in 1940. When Bantam was designing the car with the Army it was agreed that the Bantam unit was too small for the purposes...however, the vehicle had to be extremely light. About 1200 pounds. As a result Harold Crist the engineer identified two possible candidates..the Continental Y122 which was really too big until the Army raised the horsepower spec (but it was ultimately used)..and a "Hercules" engine...I would like to know more about what this engine likely was or at least make an informed guess...probably an IXLB?

Anyway, the engine would have been in the 30 hp range and be a four cylinder and it would have to have not been too tall because of the low silhouette requirement. Can any one make an educated guess as to what this engine would have been in June of 1940? Can anyone tell me about it or point me to a picture? When designed, weight, power, reputation etc?

Seems like Bantam raided the tractor bins to develop the jeep more than the car bins as most of the auxilliary stuff like starters and generators have few cross overs with cars but a few with tractors like the Cockshutt...Thanks for any help.
Bill Spear

The Herules IX engines might have been the engine considered. They were not to old of a series at that time. Now why do you think it was the IXLB version? I think your Continental was the Y-112 as I do not recall a Y-122 model.