Chris,
Man, I feel your pain. What a frustrating problem, especially since it involves frequent removal of the engine to try something new. I have nothing new to add, just pointing out the issues that seem most likely to me:
1) Lynn mentioned that your oil jets may be too big with the ball removed. That problem would look like oil pressure too low at idle but comes up to normal fairly quickly with increasing RPM
2) The thermal pellet. Easy enough to modify on you own or buy an insert from Tracy or Mazdatrix. Problem would look like too big of oil jets - see item #1.
But since you are not getting proper oil pressure even at higher RPM those are likely only a contribution to the main problem.
Thinking out loud here, it has to be:
1 - pump not picking up oil (all unlikely)
foam - unlikely
leaking pick-up gasket
insufficient oil level
clogged screen
2 - pump not pumping oil (unlikely)
key fell out even though you checked
(can be verified with oil pain removed)
improper installation
3 - oil being dumped back prematurely
Prior to reaching front cover
Improperly installed oil pump
Crossing front cover
the dreaded o-ring (can it ever really be fixed?)
oil metering cross-over
(I did just like you did with a plate over the pump mount.
there is a jet on the inside of the front
cover that sprays oil onto the oil pump chain. I keep that cross-over
intact in order to oil the chain)
something causing a blockage prior to your oil pressure sensor
that causes the pressure relief valve to open. Test this by moving
pressure sensor as close to the oil outlet as possible.
Via other oil use
to turbo
to PSRU
other?
Somewhere back in the engine
stuck oil pressure regulator
thermal pellet
too big of rotor oil jets
very loose clearance of some bearing
That is about it... and you have checked just about all of those. So it is either something on this list you did not check, or you thought it was OK but it is not.
If I were in your shoes, I would do the following.
Check the oil pressure near the oil outlet. Next, assuming the pressure is low there, consider the following:
With the engine still on the plane, remove the oil pan. Check the key in the oil pump shaft. All good there I assume.
Remove the spark plugs and prop. Rig up a large catchment that will catch all the oil that is about to come dripping out of the engine. Rig up something so the pickup is in a supply of oil but you can still see the entire underside of the engine.
With the EC2 and fuel pumps off, have a friend turn over the engine with the starter and note the oil pressure. As he keeps turning it over watch and see where the bulk of oil is coming from. Should lead you to your problem.
It is messy proposition, but better than removing the engine and doing a rebuild when you don't even know what you are fixing. If you still end up needing a rebuild, at least you will know why.
Good Luck.
Dave Leonard