Maserati developed an innovative 6.36 engine in the 1980s featuring six valves per cylinder, claiming it could produce 257 horsepower from a 2.0-liter twin-turbo setup. The Italian automaker touted the design as revolutionary, with a patented cam-rocker arrangement that reduced complexity while improving gas circulation by 34% compared to four-valve designs.

Despite the theoretical advantages, Maserati shelved the project. The company wasn't alone in discovering that diminishing returns set in beyond five valves per cylinder. Yamaha experimented with six and seven valves during development of its FZ750 but encountered detonation issues and prohibitive development costs.

The engineering lesson proved valuable across the industry. Five valves became the compromise sweet spot, delivering approximately 10% improvement in power and torque while broadening the torque curve. Ferrari, Mitsubishi, Audi, and Volkswagen all adopted five-valve designs in the 1990s and early 2000s.