Dont want to get off track here but,think about the old splash fed big ends on the old six cyl chevy for a minute. With a scoop on the rod cap to grab some
oil out of the trough for about 45° of rotation then nothing for the remaining 315°- add to that the
oil is introduced at the bottom of the stroke.
When you start to think along these lines you only need enough pressure/volume to get the
oil past the centerline of main journals ( in the main to rod journal feed ) after that centrifugal force takes over to deliver the oil to the rod journals. As long as the bearing clearance is tight enough and the drilling contains enough oil to last until it gets replenished next time around all should be ok, admittedly a bit of pressure will help, but its what they refer to as the hydrodynamic wedge that really does the 'work'. A lot of the 'High' pressure's touted by builders are at the gauge which is usually mounted on the exterior of the block, however the 'actual' pressure at the entry to the main bearing can be a lot lower- I seem to remember that for every 90° bend in hose fittings ( as opposed to 'sweeps or radius bends ) that a 5lb drop in flow pressure can be expected.
Now on that basis an FE has -70°,90°,90°,90° going from pump to filter ( no Cooler ) then 90,90,110,110 to the front main and a further 90,110 to each main in a side oiler & or about the same on a center oiler plus the trip around the cam bearings. Now if the 5lb pressure drop per 90° theory is correct we have about 50lb of pressure drop from the gallery system.
This a large part of the reason we now see oiling to both ends of the main gallery as on the alloy block pic's earlier in this thread.
Jac Mac