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Comparison of Dual Retard VCT to Continuously Variable Event Valvetrain
Technical Paper
2004-01-1268
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Variable cam timing strategies which utilize retard of the intake and exhaust valve events at part load have been previously shown to provide improved fuel consumption and feedgas NOx. These benefits can be increased by enhancing the combustion system with variable charge motion.
A variable event duration valvetrain was simulated on engine dynamometer by running a series of short duration/low lift intake valve events. The fuel consumption benefit for this simulated variable event valvetrain is compared to that of dual retard VCT with variable charge motion.
An estimated upper limit for the fuel consumption improvement potential of variable valve timing is presented. This upper limit includes both pumping work reduction and indicated efficiency improvement with high levels of exhaust residual dilution. The measured benefits of dual retard VCT and of the variable event valvetrain are compared to the estimated upper limit.
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Citation
Jung, H., Stein, R., and Leone, T., "Comparison of Dual Retard VCT to Continuously Variable Event Valvetrain," SAE Technical Paper 2004-01-1268, 2004, https://doi.org/10.4271/2004-01-1268.Also In
References
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