lifter galley crossover tube
" It's the fact that engineers KNEW decades ago that the rods need maximum oil flow at about 70~ ATDC. It moves a bit due to rod ratio but that's pretty much the standard. Every Chevy ever made has the oil timing at 70 degrees after TDC. They will oil well past useable RPM with less pressure and volume than a Chrysler. Or a ford."
I'm not saying you're wrong...you could be right....but here are my thoughts:
1) 70 degrees is a fact? According to who? I'd have to see some good evidence before I accepted that as fact.
2) We fire the ignition well in ADVANCE of when we want the combustion to take place. We do that because we recognize that nothing happens instantly...there are the usual delays. So if we want the combustion force to start at 1 ATDC we trigger the ignition at 34 degrees BTDC. So...if we want maximum oil at 70 degrees ATDC, it makes perfect sense to begin applying it a little ahead of time in order to support the development of the best oil wedge, etc. And don't forget that oil pressure doesn't cease to exist the instant the oil passages misalign...there is still a pump pushing oil through the bearing gap.