Molded camshaft assembly

A method of molding an internal combustion engine camshaft assembly including a camshaft and an integral cam lobe and with said lobe having a crowned cam profile with an apex, comprising the steps of:

• (a) providing a mold including a die component axially closeable to define a mold cavity having first surface portions in the shape of a camshaft which defines an axis of rotation and having second surface portions shaped to define the cam lobe of the assembly, said second surface portions including a radially outer surface delineating the crowned cam profile and apex of the cam lobe, said apex of said radially outer surface being disposed radially outwardly of a lower edge of a portion of said die component,
• (b) filling said mold cavity with a shrinkable fluid plastics material so that said material forms a camshaft assembly conforming to the shape of and initially engaging said first and second surface portions of said mold cavity,
• (c) delaying for a predetermined period of time so that said plastics material hardens and shrinks radially inwardly away from said radially outer mold cavity surface until the apex portion of the camshaft assembly cam profile is finally disposed radially inwardly of said lower edge of said die component portion,
• (d) and then opening said mold by moving said die component only in an axial direction so that said lower edge of said die component portion passes freely over said apex portion of the camshaft assembly cam profile.