What is acceptable oil pressure at operating temp

[Big_Guys_baby]

Hey gang,

I have been doing a bunch of searching but cannot seem to find a clean thread discussing operating temp oil pressure. I am curious what is acceptable idle and cruising speed Oil pressure would be, or at least what figures you guys are running?

[Big_Guys_baby]

Whoops! Meant to post in Early V8 Forum! Sorry

[Ricks56]

Not sure what is acceptable but my 312 runs about 65 lbs at road speed and drops down to 30 lbs at idle when hot.

[cjc56]

It is not unusual for oil pressure to be 20psi when hot and at idle. I have seen newly rebuilds that run 20 when hot at idle. Especially if you have done a good job of cleaning all the oil galley channels. I have a 304 in a 70s vechile that runs around 15 when hot at idle, but step on the gas and it goes to 30-40. Never had a problem with the engine.

[streetdreams]

I agree with Ricks56. 65# at speed and 30-35 at hot idle is what I like to see in any fresh YBlock I do.

[tdlmomowers]

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I was always told that most modern engines only require 10 psi per 1000 rpm.

[billwill]

What engine are referring of .

[Diavolo]

Originally Posted by tdlmomowers

I was always told that most modern engines only require 10 psi per 1000 rpm.

This. If the engine is under normal operating conditions, this is it. Modern engine or not, it doesn't matter. Any more is, at best, scavenging power and any less is indicative or loose tolerances or a need for thicker oil.

[cjc56]

His question was "what is acceptable". I take that to be, what is be what is the lowest psi before the engine get starved for oil. 15-20 at hot idle would still get oil to all parts of the engine. I agree a new rebuild should be more unless you have modified the oil galleys which could reduce pressure but increase flow.

[54vicky]

I agree with Rick and Street that is what all mine have when new then sometime (years) later be it shrub or my Ys

[ems customer service]

type of oil changes things a lot, i will use 10-40 or 20-50 to up the pressure if i am doing a hot slow speed cruise, i have seen 5-10 psi at idle on a hot 85+ day