Roller bearings have needle bearings. My car is drag only.
.705 lift cam. There is always the potential for a valve train failure.
The magnets and screening are to try to contain the parts in the valley area and out of the pan. Those small needle bearings in roller bearing lifters are very hard to contain. Current theory is that with high lift cams and the necessary high pressure valve springs overload the small surface area of those needle bearings and that is why they are prone to failure. Using a bushing and direct pressure oiling should
Increase durability, more surface area. I would say the jury is out on that though.
Those needle bearings almost always end up in the oil pan and sometimes they get sucked into the oil pump and lock it up ruining your bottom end bearings in the process.
