Solid roller lifters...
It's not being pressure fed like a rod bearing.
it does need a pressurised supply. [ think: rod or m/brg ]
Your wrong, simple as that..
There is no "pressurized oil supply " between the roller and the shaft.
The oil is just working it's way into the gap, same as if it were sitting a container of oil or if you were to squirt some oil onto it and turn the roller with your finger.
If anything it's acting more like a little end bearing..
It could receive enough oil from splash feed, if it's so efficient at sucking the oil into it..
No one is talking about the hydro wedge.. that comes after the oil gets in there.
One thing at a time Sparky..
