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Variable Valve Action (VVA) Through Variable Ratio Rocker Arms
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English
Abstract
Variable valve action (VVA) is achieved with a minimum of additional complexity with variable ratio rocker arms. The continuously variable ratios produce torque, power and fuel consumption curves typical of a series of differently patterned camshafts. Since the center pivot rocker arms, the rocker shaft and shaft supports are the only engine parts redesigned, a minimum of additional tooling and production cost and durability and system maintenance concerns are created. Variable valve action is achieved with: no changes in camshaft design, no changes in camshaft drive mechanisms no additional rocking or reciprocating parts, no use of hydraulic, electrical, electrohydraulic or electromechanical parts, other than the external actuating mechanism.
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Authors
Citation
Entzminger, W., "Variable Valve Action (VVA) Through Variable Ratio Rocker Arms," SAE Technical Paper 880730, 1988, https://doi.org/10.4271/880730.Also In
References
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- Authors notes from interviews