Why the hate for HR cams.

Solid lifters [ FT or roller ] have three great advantages that hyd lifters do not have:
- they can never pump up....
- they can never bleed down...
- all else being equal, they idle smoother with more vacuum because of more positive valve seating.

The problem with post #11 & 'quality' slow bleed down hyd lifters, with big duration & high lift cams, presents it's own set of problems. You get a slow bleed down rate by tightening up internal clearances. That means the smallest amount of foreign material can jam up the lifter. The levering action imparted to a roller lifter [ not in a FT lifter ] as the lifter ascends the lobe distorts the lifter body & can jam the internal piston. This is the problem you get trying to get a square peg to fit a round hole.....