Abstract: An inlet valve, an outlet valve and a pump cam are formed on a camshaft. The pump cam is disposed between and axially spaced from the inlet and outlet valve cams. An inlet valve tappet and an outlet valve tappet have end faces engaging said inlet and outlet valve cams, respectively. A cam follower is operable by the pump cam to control a fuel injection pump. A plane which is normal to the axis of said camshaft and defines the axial extent of said pump cam toward one of said tappets intersects said end face of said one tappet to define a line of intersection, whereby said pump has an overlapping portion, which axially overlaps said one tappet, and the axial projection of the periphery of said overlapping portion lies entirely within an envelope which is generated by said line of intersection around said pump cam as said camshaft is rotated.