From D. Vizards SBC book:
Oil pumps must be sized to satisfy low, not high, RPM requirements. A misconception is that the engines need more oil as RPM increases [ the clearances do not change with rpm, my insert! ] ......Consequently all oil pumps have excess delivery at peak rpm. If bearing clearances are at the wide limit....., tightening up the pump clearances helps idle oil pressure to the tune of 2-3 psi. AT A 650 rpm IDLE, 10 PSI is FINE, BUT THE PRESSURE BETTER BE UP UP TO ABOUTY 35 PSI BY 1800 RPM [ OR SO ].
