PISTON WITH VARIABLE DEPTH GROOVE ROOT

1 . A piston for an internal combustion engine, comprising:

a cylindrical piston body defining a longitudinal axis and having a top end and an outer cylindrical surface; and

a first piston ring groove formed in the outer cylindrical surface, wherein the first piston ring groove includes a groove root, an upper surface and a lower surface;

wherein the groove root has a variable depth about a circumference of the cylindrical piston body.

2 . The piston of claim 1 , wherein a depth of the groove root is greater at areas around the circumference corresponding to identified areas of liner and piston ring non-conformance.

3 . The piston of claim 2 , wherein the identified areas of liner and piston ring non-conformance correspond to areas of liner distortion.

4 . The piston of claim 2 , further including a second piston ring groove formed in the outer cylindrical surface and spaced along the longitudinal axis from the first piston ring groove.

5 . The piston of claim 4 , wherein the first piston ring groove is positioned closer to the top end of the cylindrical piston body than the second piston ring groove.

6 . The piston of claim 1 , wherein the upper surface and the lower surface are substantially parallel.

7 . A piston assembly for an internal combustion engine, comprising:

a piston having a cylindrical piston body and having a top end and an outer cylindrical surface, a first piston ring groove formed in the outer cylindrical surface, wherein the first piston ring groove includes a groove root, an upper surface and a lower surface;

a piston ring at least partially received within the first piston ring groove; and

a cylinder liner receiving the piston and having an inner surface;

wherein the groove root has a variable depth about a circumference of the cylindrical piston body.

8 . The piston assembly of claim 7 , wherein the inner surface of the cylinder liner has identified areas of liner and piston ring non-conformance; and wherein a depth of the groove root is greater at areas around the circumference corresponding to the identified areas of liner and piston ring non-conformance.

9 . The piston assembly of claim 8 , wherein the identified areas of liner and piston ring non-conformance correspond to areas of liner distortion.

10 . The piston assembly of claim 8 , wherein the upper surface and the lower surface are substantially parallel.

11 . The piston assembly of claim 7 , wherein the piston ring is substantially cylindrical.

12 . The piston assembly of claim 7 , wherein areas of greater depth of the groove root about the circumference of the cylindrical piston body define areas of higher gas flow between the piston ring and the groove root relative to remaining areas of the groove root.

13 . The piston assembly of claim 12 , further including a second piston ring groove formed in the outer cylindrical surface.

14 . The piston assembly of claim 13 , wherein the first piston ring groove is positioned closer to the top end of the cylindrical piston body than the second piston ring groove.

15 . A method of manufacturing a piston for an internal combustion engine, wherein the piston includes a cylindrical piston body and has a top end and an outer cylindrical surface, the method comprising steps of:

determining identified areas of liner and piston ring non-conformance along an internal surface of a cylinder liner; and

forming a first piston ring groove in the outer cylindrical surface having a variable depth groove root, varying about a circumference of the cylindrical piston body at areas corresponding to the identified areas of liner and piston ring non-conformance

16 . The method of claim 15 , wherein the determining step includes identifying areas of liner distortion.

17 . The method of claim 15 , further including forming a second piston ring groove in the outer cylindrical surface.

18 . The method of claim 17 , further including positioning the first piston ring groove closer to the top end than the second piston ring groove.