In the late teens Duesenberg sold the manufacturing rights of the 4cyl. engine to the Rochester Motor Company and the factory it was built in to the Willys Motor Company. After this Duesenberg moved to Indianapolis to build the 8cyl. engines. The 4cyl. Rochester Duesy was an earlier version of the 'walking beam'. Do a search on Roamer and Revere cars. They were fitted with these engines.
Magnificent equipment from a time when the a few had money to play with. Magnificient engineering from a time that had self-taught men.