Gm Global Technolgoy Operations, Inc.

Ramachandra Diwakar

Edward G Groff

Keith Meintjes

Alberto Lorenzo Vassallo

Roger B Krieger

Vicente Domenech-Llopis

Richard C Peterson

David Darin Wickman

Shengming Chang

A piston for a diesel engine includes a piston body having a skirt and crown. The piston body has portions defining an outer combustion bowl and an inner combustion bowl within the piston body through the crown. The outer combustion bowl has a curved annular side wall extending from the crown surface and an annular flat shelf extending from the curved annular side wall. The new stepped bowl design integrates a bottom profile with smoothly varying curvature and a sharp step at the top. The annular flat shelf is recessed a distance in the range of 2.5-4.5 millimeters from a line coplanar with the crown surface. The piston body defines an outer convex curved surface connecting the curved annular side wall to the crown surface. The outer convex curved surface has a radius of curvature in the range of 0.25-0.75 millimeter.

Diesel piston with sharp-step profile

A piston for a diesel engine has a crown and a three-dimensional shape defined in an x-y-z coordinate space. The z-axis generally defines a cylinder axis of the piston, and the plane z=0 generally intersects an upper rim of the crown. The piston includes a combustion bowl recessed in the crown. The combustion bowl has a center point on the z-axis and has a two-dimensional partial cross-sectional configuration defined by a peripheral line connecting coordinate points (x,y,z) in the x-y-z coordinate space. The (x,y,z) coordinate points include points from a coordinate set S. The combustion bowl has a three-dimensional axisymmetric configuration defined by rotating the peripheral line 360&#xb0; about the z-axis.

Low emissions diesel piston

A two-stroke cycle spark ignition engine having cylinder fuel injection is provided with a combustion chamber featuring a delta shaped bowl or cavity that is configured and positioned in the cylinder head to improve scavenging of the combustion chamber near the injector while maintaining adequate squish flow for improved charge mixing and combustion.

Two-stage cycle engine and combustion chamber

A direct injection internal combustion engine of the diesel or spark ignition type is provided with a combustion bowl recess in the head end of the piston having both a polygonal lip and a polygonal bowl with upwardly and inwardly curving reentrant sides to provide high turbulence for fuel air mixing during an extended portion of the piston compression stroke and improved combustion of the air/fuel mixture.

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Troy, MI, United States of America

Ramachandra Diwakar