The Practical Application and Effects of a Variable Event Valve Timing System

Lancefield, Tim; Gayler, R. J.; Chattopadhay, A.

doi:10.4271/930825

Cited by 25 publications

(7 citation statements)

References 3 publications

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“…Although, they do require head and valve train layout changes and are clearly more complex than phasers or conventional fixed valve train. On the basis of the foregoing analysis it was decided that the investigation should be carried out using a variable velocity system, based on the work of Mitchell [31] [32].…”

Section: Variable Velocity Systemsmentioning

confidence: 99%

The Application of Variable Event Valve Timing to a Modern Diesel Engine

Lancefield¹,

Methley²,

Räse³

et al. 2000

SAE Technical Paper Series

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DaimlerChrysler and Mechadyne have undertaken a piece of work to investigate the opportunities for improving the operation of light duty diesel engines using variable valve timing. The very high compression ratios used in this type of engine make it essential to be able to alter the valve open periods to affect exhaust valve opening and intake valve closing, whilst leaving the valve motions largely unchanged around overlap top dead centre to avoid valve to piston contact. This paper presents an overview of the design solution, a description of the simulation model used, performance and economy data predicted by the model and a discussion of other areas of opportunity where improvements may be possible.

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Section: Variable Velocity Systemsmentioning

confidence: 99%

The Application of Variable Event Valve Timing to a Modern Diesel Engine

Lancefield¹,

Methley²,

Räse³

et al. 2000

SAE Technical Paper Series

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“…A feasible way to reach beneficial effects on performance, emissions, and consumption is the development and the application of variable valve actuation (VVA) systems. [1][2][3][4][5][6][7][8] Both the results of experimental tests and the performance of the modern automotive engines on which they are currently employed show the good perspectives of the implementation of different strategies reachable by the use of VVA systems. [9][10][11][12][13][14] The main strategies currently used in automotive field are timing variation, duration variation, maximum lift variation, combined but not independent variation of timing, duration, and lift.…”

Section: Introductionmentioning

confidence: 99%

New mechanical variable valve actuation systems for motorcycle engines

Abagnale

Migliaccio

Pennacchia

2014

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper summarizes the results of the design of new mechanical variable valve actuation systems, developed for highperformance motorcycle engines, at University of Napoli Federico II, Department of Industrial Engineering -Section Mechanics and Energy. After a synthetic recapitulation of the main variable valve-actuation methods and of the main beneficial effects on performance, emissions, and consumptions of the modern automotive engines on which they are currently employed, the paper presents the results of our mechanical variable valve actuation systems, born to be applied on a MotoMorini engine, as required by the company. The paper starts with the description of a first study concerning a very simple system, used just to set up a model to be used for further and more complex activities. The study has been conducted implementing a numerical procedure specifically designed to determine cam profile and kinematic and dynamic characteristics of the whole system, starting from some input data (as described later). The model has been validated against the conventional timing system using kinematic simulations. The work has evolved through three main steps leading to three types of variable valve actuation systems, all mechanical systems (as defined in literature and described later). Results of the numerical procedure verify the validity of the variable valve actuation systems, and particularly, the last one shows a complete performance in terms of lift, duration, and timing variation of valve-lift law. This paper reports results reachable with these simple systems that give good perspectives of use for a new two-wheel vehicle engine.

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“…Many automobile enterprises and scientific research institutions have carried out research on it, achieving a great deal of results [2][3][4][5][6][7][8]. So far, there is a lot of commercial VVT technology.…”

Section: Introductionmentioning

confidence: 99%