In 1916 US automotive magazine Automobile Topics described a four-cylinder, four-valve-per-cylinder car engine made by Linthwaite-Hussey Motor Co. of Los Angeles, CA, USA: "Firm offers two models of high-speed motor with twin intakes and exhausts."
Bugatti also had developed a 1.5-liter OHV straight-4 with four valves per cylinder as far back as 1914 but did not use this engine until after World War I.