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A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1992 by SAE International in United States
Annotation ability available
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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CitationShibano, K., Kamimaru, S., Yamada, T., and Watanabe, K., "A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction," SAE Technical Paper 920451, 1992, https://doi.org/10.4271/920451.
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