Browse Publications Technical Papers 2002-01-1109
2002-03-04

Production Electro-Hydraulic Variable Valve-Train for a New Generation of I.C. Engines 2002-01-1109

Recently [SAE 2001-01-0251], we reported for the first time on using a fully variable valve train (FVVT) to facilitate controlled auto-ignition (CAI) in 4-stroke gasoline engines, with a 23% reduction in fuel consumption and a reduction of up to 95% in emission levels. In this paper we look at the industry trends towards increased control over combustion related processes occurring in modern engines, which signaled the direction towards the CAI work, and review a range of valve train technologies available to meet these trends. Previous key work conducted by industry and academic researchers is also reviewed to establish a minimum specification requirement for the new fully variable valve train systems. The paper then describes two electro-hydraulic valve actuation systems capable of meeting these specifications, the first a research grade system used on single cylinder engines and the second a new production viable system that is aimed at bringing FVVT's to high volume production. System design features and layouts are discussed with results from test stand development and traces of some of the unique valve timing events taken from a running engine fitted with FVVT demonstrating true unthrottled engine operation.

SAE MOBILUS

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

Access SAE MOBILUS »

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:
TECHNICAL PAPER

Cam Profile Switching (CPS) and Phasing Strategy vs Fully Variable Valve Train (FVVT) Strategy for Transitions between Spark Ignition and Controlled Auto Ignition Modes

2005-01-0766

View Details

TECHNICAL PAPER

The Electro-Hydraulic Valvetrain System EHVS - System and Potential

2005-01-0774

View Details

TECHNICAL PAPER

04 Emission Reduction by Cylinder Wall Injection in 2-Stroke S.I. Engines

2002-32-1773

View Details

X