Thank you. That all makes sense to me.
and now for the next inquiry. Is the following scenario possible or probable?: Harley says to adjust their pushrods to 2.5 turns. That would put the preload on the lifter at .104 preload. (24 TPI). Would it be wrong to assume that when the engine gets hot and everything expands that the ability of the oil pump to move the proper amount of oil into the lifter at slower rpms, is not enough to prevent the push rod from bottoming out, or coming close to bottom?

 

Actually in the cases of the pushrod centered to 0.140 or more, the pushrod typically does not bottom out the lifter. It's probably not until the pushrod is adjusted until about 0.010" from bottomed that it actually can bottom out.. When you hear lifter noise it's not the lifter bottoming out but the valve dropping hard on the valve seat. Going deeper simply helps with recovery.

Tho I wrote:

It's probably more appropriate to say, " Because it doesn't collapse as far so it's easier to recover."

Some of that may be due to preload on the little spring inside the lifter is a little more and a little deeper may also bleed a little less.

 

Its an M8, no rocker lockers

 

I do like your responses. They make me understand more, think more, and ask more questions. My next one is, if the valve is dropping hard on the valve seat, would there be a proper adjustment to help quiet that down?

 

Generally it boils down to better lifters with less bleed. One thing to note on a M8 is that the valve stem protrusion on both one side (intake or exhaust) needs to be the same for the 2 valves. If not then one valve will hit the seat harder. One thing you can do is buy rockers that have an adjustment to balance valve lift.. HD makes some.. I've not used them but a few here say it's helped.

My M8 is stage 2 with stock mufflers.. It will likely stay that way..

 

Could simply be valves closing on seats......... Changing the cam profile usually results in extra lift and longer duration which by definition deceases ramp time closed to open and open to closed which can result in valve train noise. I know on every new bike I have added a performance cam to the 1st thing I noticed was new valve train noises.

Kinda old school but a piece of wood rod radiused at both ends makes a great stethoscope. Go cut the end off your ol'lady's wooden broom handle and sand a radius on the cut end. Take that to the engine and place the factory smooth edge on your ear while you move the other end around on the engine. You will hear everything internal to that engine and you will kow exactly where the noise is coming form.