How can the oil pressure be adjusted up?
Hi Chinesespaceman
When you set your pressure relief valve to a nominal pressure, say 40psi, that is the pressure that it will open at to maintain the 40 psi.
If your engine once warmed up drops to 20 psi, the oil pressure is not reaching the cracking pressure so adjusting the pressure relief valve will have no affect.
Some options, the px valve is leaking, the oil cooler vernatherm valve is jammed, oil pump is worn.
Crankshaft bearing clearances are too large.
When the engine was overhauled, was the oil cooler and vernatherm valve serviced?
Cheers
BH