Ford: oil pressure, ford 460 engine, fe engines

Question
QUESTION: hi, i have a ford 460 engine with oil pressure problems. the engine was totally rebuilt last year and has standard size pistons. the oil pump was new. i recently replaced it thinking it was the problem. when the engine is first started it has 40 psi, after warm up it drops to 0 psi. but the engine does not make any noise. reving it builds oil pressure. my bearings are all within specs. ??????

ANSWER: what weight oil are you running?

---------- FOLLOW-UP ----------

QUESTION: i have tried 10w-30 then switched to straight 40 with no
change to psi. my engine is a 71. i have heard that the
fe engines were high volume, not high pressure as far as
the oil goes, could this be true?  thanks

Answer
are you using the stock oil PSI gauge or an "actual pressure" gauge which is more accurate? if you are running 40 weight your pressure should be right up around 55 PSI, even when warm and you are right, Fuel Injected engines run more pressure then their older carbureted counterparts which like to run at a high PSI. they also have a larger crankcase capacity to off set the increased oil pressure. if you don't have a pressure gauge that displays anything but NORMAL, get on and unhook the stock oil sending unit hook it up and see what your engine is putting out for pressure, 10-20 lbs at running temp at low idle is about right for a carbed motor.