where is the oil pressure relief valve?

pmfranke · #1 (**permalink**) 10-11-2006, 07:02 PM

74' 351 melling high vol oil pump.is it in the pump? my press stays at 50 to 60 all the time.idle and 5500 rpm. whats up?

jarendall · #2 (**permalink**) 10-12-2006, 06:31 PM

sending unit, gage, plugged oil line or just a good steady pressure, mine swings a little, I am also runnning a melling high volume oil pump, usely runs between 45 and 60 lbs. not much difference from yours

slithering · #3 (**permalink**) 10-12-2006, 08:08 PM

oil releif is built into the pump

Scufty · #4 (**permalink**) 10-12-2006, 08:36 PM

for sure check your sending unit ...all I did was take mine off and clean it ..put new wire connecter and it made a huge difference

Rick Parker · #5 (**permalink**) 10-12-2006, 08:37 PM

pmfrank:

Your bearing and rod side clearances are probably on the low side (tighter) of the scale, consequently the pump easily keeps up with requirements of gallies and bearing clearances. If clearances were greater, more oil would bleed off causing more of a fluctuation from idle to 2500RPM+. You're indicated pressures are ok.

wtm442 · #6 (**permalink**) 10-12-2006, 09:05 PM

Nothing is wrong

My oil pressure for the last 10K miles has been between 55 and 60 PSI at all RPM's.

trularin · #7 (**permalink**) 10-13-2006, 06:01 AM

The valve is part of the pump. There is a cotter pin or bolt that retains the pressure spring. The old days trick was to shim the plate or plug the bolt or cotter pin held back with a washer to increase the pump pressure.

That pump pressure you are posting is good. I agree with the statement you probably have your clearances a bit closer.

pmfranke · #8 (**permalink**) 10-13-2006, 11:20 AM

Thanks for the reasurance,some of the guys report 100 lbs of pressure on a new engine and i wondered why mine was not up to snuff.