Any Pontiac guys on here? Need insight.

Bewy said
First.
Post #107 is incorrect. The disc meters oil through the p'rod to the top end. What 'shuts' up the lifter is the valve at the base of the inner piston. not the disc.

Second.
The flat disc with 4 holes in it in post # 108 is used to meter oil through the prod. But how can get through the holes to get the hole in the prod socket when oil pressure is forcing the disc against the prod socket??? I am 99% sure this is how it works. With a hyd lifter, the lifter bleeds down slightly as the lifter rides over the cam lobe; this creates a gap under the prod socket & oil gets pumped through the 4 holes, into the prod socket, & into the prod.
Sol lifter, it has the lash clearance, works the same way.

The bottom of the pushrod socket or cup or plunger( whatever you want to call it) has a raised surface on it that goes around the outside of that disk but the center has a pocket that allows the oil to get out of the inner chamber and up the push rod for the ones with the holes in it. The ones with a solid disk, the disk either can have like a notch kind of shape in the corner or the disk has like an arc to allow oil to escape out of the inner chamber of the lifter and travel up the pushrod. The size of the notch or arc of the disk meters the amount of oil that gets out. I will be messing with it soon so I will take a picture of this. This is a picture of one with a solid disk in it, it's hard to see but, if you notice the shading on the disk, it's because it has an arch in it.