It probably makes more sense than you think.... now.
IIRC those cups were oiled thru the adjusters or thru a verrry small passage in the arm itself. Liquids are just like electricity in that they will take the path of least resistance. In your case 50 psi wasn't enough pressure (voltage if you will) to overcome the resistance of the passage compared to other sources of escape near by.
Kevin
I smell what you are steppin in...but...
I had the same issue on 2 different motors. Different blocks, heads, etc.
I tried 5 different sets (Brands) of rockers. 4 different sets of shafts. 5 different lengths of pushrods. Different adjusters. Hollow adjusters. Shimmed the rockers super tight. I even "turned" the hold down hardware down a few .001 to get more flow through the shafts. Id estimate I pumped 5 gallons of oil out of the dang motors onto the ground.
While it is a "crappy" design, it doesnt take much oil to keep the cups happy.
The only common factor to everything is an oil additive I used/still use. SLOB. I cant see that it would be the "cause"
While I understand what you are saying...quite a few guys have less to much less pressure than I have. Esp the guys with non bushed blocks with roller lifters. Ive not heard of anywhere near the issues I had.
72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72.
Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.
