Browse Publications Technical Papers 2004-01-1268
2004-03-08

Comparison of Dual Retard VCT to Continuously Variable Event Valvetrain 2004-01-1268

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.

SAE MOBILUS

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

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 16% 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

Benefits of the Electromechanical Valve Train in Vehicle Operation

2000-01-1223

View Details

TECHNICAL PAPER

Experimental and Simulation Analysis of PFI-SI Engine for Fuel Economy Improvement

2005-01-3691

View Details

TECHNICAL PAPER

A Newly Developed Variable Valving Mechanism with Low-Mechanical Friction

920451

View Details

X