Engine has 80 lbs of pressure when oil is cool; as the temp goes up, the pressure drops. By the time the oil is 200 degrees, the pressure is down to 40. The odd part is that it has 30psi at idle; rev it up and all it will make is 40psi. There are two gauges on the engine; one just after the remote oil filter and one in the main gallery of the engine, of course after the thermostat and coolers. They both read very nearly the same at all times; one is mechanical the other electrical.
Any guesses as to the problem?