A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction

Kenji Shibano; Shinji Kamimaru; Takemasa Yamada; Kenzo Watanabe

doi:10.4271/920451

1992-02-01

A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction 920451

Since the intake and exhaust valve timings that provide the best fuel economy, idle stability, or highest power change according to the engine operating zone, a variable valve timing system is very beneficial.

Also, roller followers, which reduce mechanical friction loss of a valve train mainly at low engine speed, are commonly used to improve fuel economy in urban driving conditions. This paper presents a newly developed 4-valve variable-valve-timing mechanism with roller followers.

Different intake- and exhaust-valve timings and lifts are selected independently, depending upon whether engine speed is low or high.

Durability tests of running at maximum engine speed and switching between low- and high-speed cams were conducted and good test results were obtained.

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A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction 920451

SAE MOBILUS