For anyone that follows The OLD MOTOR, David built a engine like this from scratch called a walking beam. Cast a block, did ALL the machine work, then made all the little parts. Those arms on the side are rocker arms as the 4 valves per cylinder are horizontal.
Info on the Duesenberg walking beam can be found here- https://www.jalopyjournal.com/forum/threads/unusual-engine-photos.1123661/page-49#post-14464391 Thanks @noboD, I was not aware of the re-creation of the Duesenberg walking beam, I wish more details had been shared on "The Old Motor".
David had pictures of individual parts a few years ago, MIGHT be accessible on the site. As I remember he had a junk block, made a pattern and cast a block. Then cut it apart to measure thickness and adjusted the pattern and cast a new block. Pretty impressive accomplishment.
The Jalopy Journal
