Browse Publications Technical Papers 2018-01-0878

The Dual Mode VCS Conrod System – Functional Development and Oil Investigations 2018-01-0878

Variable Compression Systems (VCS) for Internal Combustion Engines (ICE) will become increasingly more important in the future to meet stringent global fuel economy and CO2 standards. A Dual Mode VCS is in development at AVL and the basic functionality and potential were described in a technical paper which was presented at the SAE WCX 2017 [1]. The system is based on a hydraulically switched and locked conrod with telescopic shank.
The AVL Dual Mode VCS was designed and virtually optimized with CAE simulation methods for the boundary conditions of a typical 2.0 L Inline (I) 4 Turbocharged Gasoline Direct Injection (TGDI) engine representing state-of-the-art gasoline engine technology for the next years to come.
Rig tests and motored Single Cylinder Engine (SCE) testing were performed with the Dual Mode VCS hardware to investigate the influence of the oil characteristics on the function, such as different oil grades, different oil temperatures, aged oil, oil aeriation and oil contamination.
Fired SCE and full Multi Cylinder Engine (MCE) tests were performed to validate the general function in the typical operating range of automotive TGDI engines, such as behavior under different mechanical and thermal loads and speeds.
The impact of friction and parasitic losses on the fuel economy were investigated and are discussed in this paper.
This paper also describes and discusses some of the main development results which have been obtained for the Proof of Concept (PoC) and for the completion of the functional and design validation.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Modified Experimental Approach to Investigate Coefficient of Friction and Wear under Lubricated Fretting Condition by Utilizing SRV Test Machine


View Details


Potentials of External Exhaust Gas Recirculation and Water Injection for the Improvement in Fuel Economy of a Poppet Valve 2-Stroke Gasoline Engine Equipped with a Two-Stage Serial Charging System


View Details


Electromagnetic Fully Flexible Valve Actuator


View Details