Abstract: A valve stem seal provides an elastomeric main valve body having an upper working portion and a lower support portion, the latter for support of the seal on a valve guide member. The seal contains a central helically threaded internal region adapted to meter oil flow betwen the valve guide and a valve stem reciprocally moveable with the guide. The upper working portion defines a pair of ends, wherein each end contains a non-threaded internal portion defining a plurality of alternately arranged axially extending grooves and ribs. The grooves provide oil flow passageways, while the ribs support the ends of the working portion against the reciprocal valve stem member. In a preferred form, the non-threaded internal portions have axial lengths within a range of one-tenth to one-third the axial length of the central threaded region.