rob ss
the poundages quoted by js were at peak lift, whereas you are talking about pressures at other lift positions.
The worst situation for camshafts and followers is at very low engine speeds, usually only a few hundred rpm. Here the oil entrainment is chronically bad, in the region of 0.04 microns thick, while Hertz stress is very high, typically 950 Mpa. At 8000 rpm the oil entrainment is drastically improved by better than a factor of 10, while the Hertz stress is almost halved.
At high rpm the inertia of the valve, retainer, collets and a portion of the upper spring coils, rocker inertia, pushrod and cam follower, leaves very little spring pressure available to bear on the surface of the cam.