Hyundai Motor Company

Kia Corporation

Ankith Ullal

Kyoung Pyo Ha

Mark Shirley

Shengrong Zhu

Jeffrey Hollowell

Nicholas Fantin

Vincent Costanzo

Nam Kyun Kang

Systems and methods for improving engine low load performance are provided. The method may comprise performing a negative valve overlap (NVO) mode of operation, using an early exhaust valve closing (EVC) timing that is earlier than the intake valve opening timing and creates an NVO during a gas exchange top dead center, to compress in-cylinder gas and increase overall gas temperature for improved fuel vaporization, mixing, and reforming before the fuel-air mixture is burnt. With NVO operation, a low temperature combustion (LTC) mode may be used to improve engine combustion efficiency and reduce emissions. With the NVO operation at low loads, the engine intake may be wide open or less throttled, reducing pumping loss. A method based on a rate of change in the engine speed and load for the combustion mode transition between spark ignition (SI) and LTC modes is provided.

Multimode engines with advanced valvetrain systems and methods of use

Growing community of inventors

Superior Township, MI, United States of America

Ankith Ullal