High thread spark plug with non-axisymmetric ground shield for precise ground strap orientation

A spark plug for an internal combustion engine, the spark plug comprising:

• an elongated center electrode having a center electrode tip at a first end and a terminal proximate a second, opposite end;
• an insulator substantially surrounding the center electrode and extending along an axial plug axis, said insulator defining first and second transverse axes extending in a common plane perpendicular to said axial plug axis and transverse to each other, said insulator comprising a first insulator section surrounding said center electrode along an axial length extending from said electrode tip, and a second insulator section axially adjacent thereto, wherein said first insulator section has a narrower diameter than a respective diameter of said second insulator section;
• a ground shield surrounding said first insulator section proximate said center electrode tip and defining a ground strap in spaced relation from said electrode tip to define a spark gap therebetween;
• a shell substantially surrounding said second insulator section;
• a jamb nut rotatably supported on said insulator axially outwardly of said shell, wherein said jamb nut axially contacts said sleeve to axially drive said spark plug into said plug hole during spark plug installation;
• and
• said ground shield having an outer shield surface which is non-axisymmetric relative to at least one of said first and second transverse axes to define a predetermined orientation in which said spark plug is installable within said plug hole.