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Hi guys! What is a good oilpressure in a 68 383?
That is a really open question. A rebuilt one with a high volume pump will show a much higher reading than a 300,000 mile engine with 5w20 oil. Maybe if you described the condition of the engine it would help to determine what is in the normal range. All big blocks will have similar numbers if they are in equal condition. Usually, an engine in good condition will have a cold start idle reading over 70 psi with a 30 weight oil. My 440/493 runs 80 when cold in Park or neutral. In gear at idle of around 750-850 rpms when warm and in 100 degree heat, it may drop to 25 momentarily but once the rpms come up above 1000, it responds and leaps over 50 again. Chevys typically run lower pressures. I drove Chevys for years and when I built my first 440, I was shocked at how high the pressures were for Mopar engines.
45-50 lbs for a stock BB Mopar engine, is normal.
Bearing clearances will determine where your pressure is at as well. A performance engine with a little more main and rod bearing clearance will have a lower pressure than a stock engine with tighter clearances as well. Alot goes into factoring oil pressure. I'd say any stock style engine with 40-50 lbs of oil pressure at operating temp is pretty healthy with stock pump and bearings. Obviously it will drop a bit at idle no worries there either.
Yep, factory service manual says 45-60 at 1000 RPM. My own 440 (of unknown age/build, but supposedly pretty fresh) starts cold at 80psi, then drops off to a sort of scary hot oil pressure at idle of 25 (750 RPM), but jumps the moment you touch the throttle. What oil you run, the condition of it, all sorts of factors can affect this - including what filter you run. Of course, how accurate your oil pressure gauge is matters as well. I actually run a thinner weight oil than my instincts tell me to (10W30) because the pressure gets pretty scary high when cold.
Why do you ask? What are your concerns? What oil pressure are you seeing?
I run 75 Pds cold at idle. After running around it runs 25 at idle but jumps right back up at 60pds
72# down the road cruising @ 2500 RPM.
Sorry, but this is not accurate enough of a response. 45-50 lbs when? At idle? At 6000 rpms? with an old engine or a fresh rebuild? Thick oil or thin? Too many variables to pin down without the OP responding with more info.
What part of 'stock' don't you understand? My 440, once it's fired up, has 50 lbs. Stays there, until it's warmed up. 3000 rpm stays there. Once warm, at idle, it's 25-30 lbs. Engine is mostly stock, though with a 1/2" oil pick-up, with a stock oil pump.
At 6000 rpm you should have at least 3000 psi
What if you only have an idiot light and no guage?
Relax. Just writing a number like 45-50 lbs is pointless until you give it context. You didn't mention at what rpm, what oil or what temperature. Your number is a good one but it gives no reference to anything. 60 wt oil with a worn out engine can generate that number at 4000 rpms. I brought his daughter home at 8:00 PM....why is the Father so pissed off? He wanted her home before 9:00. He is pissed off because I brought her home at 8:00 PM three days late. See ? Now the context makes sense, right?
One might argue that it's the OP's lack of context that is the issue. In light of the question, Miller's responds is as good as any. My answer to to question would be 10 to 90 psi.
They call 'em that for a reason, my friend.
His original answer? Not so much, because oil pressure in an engine is stated at a given RPM - so half his response was missing.
But what rpm? Are we suppose to guess what rpm the OP wants, or just give it to him in 5 rpm increments? And what kind of 383? For what purpose? Between the pump type, bearing clearance, and oil viscosity any answer could be right or wrong. An OP should not expect any better of an answer than he/she is willing to put into the question.
When in doubt, spout off factory numbers like I did - and hope the OP actually returns to finish his question.
The light that comes on ten minutes after the tow truck gets there!