You have to increase the dwell time IF the oil timing is off. That’s the band aid. Like full groove mains. You are getting oil to the rods all the time.
If you read that paper that Phreakish posted they discussed putting oil in at TDC. Or shortly after. Pretty interesting.
Again, I use the SBC a my example. They don’t need full groove mains, more dwell time or any of that, because the oil is there, full flow, full pressure at the correct time.
Obviously if the big end of the rods don’t stay round, or they have too much clearance (almost as bad as too little clearance) the pan sucks or some other issue, that system is pretty much bullet proof, even if you oil the mains after the cam the OE stuff did for decades.
EDIT: forgot to mention this question, because it has me scratching my head. The mains get oiled first. So how the mains get starved and not the rods? Or did they both get it.
I think I said this earlier but I prefer to groove the cam and restrict the oil in 2 and 4 rather than just restricting oil there. You can cut the others back more, but 2 and 4 can still get cut back quite a bit if they are getting full time oil.