Thread: oil pressure problems

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greein's all been lookin for help and this seems to have the most knowledgable people that I have found. What I have is an 68 390 block that I am working with. I have stroked it from a 390 to 430, crane cam system, edlebrock heads & intake, msd ign, system and other oddes and ends. My problem is just started it upfor the first tiime the other day and my oil press is only 15 psi at idle and 40 psi @ 2000 rpms the pressure doesn't jump up; it steadily rises with rpm. I have search for the specs but haven't been able to find anything. I know it's low but how low is exceptable.the pump is a HV and all of the passages were cleaned @ mach. shop. any clues as to were to start looking.
thanks

My old worn out 390 goes to 60 psi on startup and idles at 25 psi hot.

everyting is new. I was running castrol 20-50 w/ KN oil filter. Talked w/ guy to built the bottom end he sugested try a Motorcraft oil filter and then switching to straight 40w. tried that still running 15 @ idle. Listen to the oil pan and along the block there isn't and noise. check my oil filter adapter (new aftermarket) the gasket didn't blow out and design doesn't allow for oil to go anywhere but to and from the filter. I have a decent flow at the rocker shafts, also check for any of the lifters leaking but they're all firm.

Is the screen on your pickup clean? And, is there enough clearance between the pickup and the bottom of the oil pan?

the pick up screen is clean. as far as the clearance goes the pan and tube are OEM but it is something to check. thanks

40 pounds at 2000 rpm isn't a problem, as long as it stays there when the engine gets warmed up. What's the pressure at, say, 3000?

the pressure doesn't get much higher if the throttle is snapped to WOT the pressure exceed 50 but if you hold it around 3g the pressure is around 40. the pump is a HV so not too worried about off idle pressure as it moves up w/ rpm i'm worried bout 15 psi cold and 10-11 hot.

Any update?

Just a thought but my brother had the same problem with a 327 that he had. Turns out that the oil pump screen actually fell of of the oil pump itself. Needless to say he thought it was fine at low psi at start up till in the end the cam bearings went out and the rod bearings went out. His engine now sits in my garage with no crank and no hopes of seeing an engine bay anytime soon. So when I built my engine I had my oil screen pick up tube tach welded so as to never worry about that problem.

greetin 's been busy thankd for the help. I replaced the pump and pickup tube and the pressure reutrn to normal around 25psi hard to believe that i got faulty pump but such is life.

I had this problem once on a brand new motor and you won't like what my problem ended up being.
I failed to get enough lubriplate grease on the main & rod bearings during assembly & ended up replacing them AGAIN ...after turning the crank. I hope this is NOT the case with your motor.
Good luck.