The discovery of this photo prompted us to search out other Peugeot photos and construction details, which will show you this brilliant dohc, four-valve four-cylinder engine designed by Boillot-Goux-Zuccarelli or “Les Charlatans” as they were called. Boillot and Goux were both racing drivers and Paolo Zuccarelli was a very talented practical engineer-mechanic. This engine that they created in 1912, established the dohc four-valve layout that is still in use to this day.

In 1898, Detroit bicycle manufacturer Walter Lorenzo Marr built a motor-trike with a one-cylinder OHV engine with push rods for both exhaust and intake. In 1900, David Buick hired Marr as chief engineer at the Buick Auto-Vim and Power Company in Detroit, where he worked until 1902. Marr's engine employed pushrod-actuated rocker arms, which in turn pushed valves parallel to the pistons. Marr left Buick briefly to start his own automobile company in 1902, the Marr Auto-Car, and made a handful of cars with overhead valve engines, before coming back to Buick in 1904. The OHV engine was patented in 1902 (awarded 1904) by Buick's second chief engineer Eugene Richard, at the Buick Manufacturing Company, precursor to the Buick Motor Company. The world's first production overhead valve internal combustion engine was put into the first production Buick automobile, the 1904 Model B, which used a 2-cylinder Flat twin engine, with 2 valves in each head. The engine was designed by Marr and David Buick.