lowest oil pressure for engine to survive

[Brian]

So, how does oil being dumped by the relief valve get heated anymore than the oil flowing through the bearings, removing heat from the bearing as it does so? If the oil going through the bearing is removing heat from the bearing, it is doing so by absorbing that heat. Oil returning to the oilpan through the relief valve is doing exactly that; returning to the pan. So how is it getting heated? Surely it is at the same temperature upon leaving the pump as the remainder of the oil that circulates throughout the rest of the engine?