Stuffed lifter?
I should add my feedback on my experiences I guess:
1st RB26DETT: Stock 15 year old motor, ~120,000km
WSID drag strip - had just run a 12. Second run small launch, got to the top of 3rd gear and the oil pressure light came on - bad news. Shut it off at the top of 3rd and coasted over for a 12.5 .. motor needed rebuild, had not spun a bearing yet but was in bad shape. Ended up selling the motor for a 2nd hand rebuilt motor.
May be important to note that in the months upcoming this failure the oil pressure (stock) gauge was playing up, occasionally going to zero. I can only assume this was early warning to the failure....
2nd RB26DETT - N1 spec bottom end, metal HG, cams, T04Z. ~10,000km on motor.
Another oil pump failure at high revs ~8000rpm, the oil pressure light came on and that was the end of that oil pump. It'd almost literally cracked in half - the theory is that the balancer was not properly balanced, and the combination of (over time) hitting the rev limiter with such ferrocity resulting in the crank (JUN crank collar) rocking back&forward and therefore the resulting failure. Any alternate theories welcome!
Was no warning with this one - was running perfect one day ~500rwhp and the next day broken. Pulled the motor down and it was in good condition, could've put it back together with a new oil pump and driven away, or at minimum new bearings & rings. Decided for a full build and sold the car before it ever got a big power tune after run in...