Good oil pressure?

[kevinrocks]

What is a good oil pressure for a stock bore 305. I have an unknown cam size, edelbrock intake, and headers. The rest is stock, (minus the heads being in question) At wide open throttle, I get about 30-35psi right now, and around 20-25psi at just a steady cruising speed. At idle the psi drops down to around 5psi or so.

Is the motor showing age? (i'm sure it is) I really have no clue what an ideal oil pressure is for this motor.

 

[jerrycad472]

http://gbodyforum.com/viewtopic.php?t=1626&highlight=Oil+pressure

Here is a link to a previous discussion on the topic of oil pressure.

 

[bigdan]

first id verify with another gauge ...

your pressure is too low ;-(

normaly sbc get 30-35 at part throttle and around 20 at idle

if your gauge is right , your bearings are probably shot ( over .0035 clearance)

Dan

 

[ryanwitski]

i always go by 10 psi for every 1,000 rpm min. I have had an 84 elky and my 91 camaro that idle just above 10 psi and trust me they run great.

 

[kevinrocks]

Thanks for the link to the other thread. I guess I should have searched first. 😳

I'm unsure of my RPMS because I do not have a tach yet, but The oil pressure does go up with more throttle.

I'm just asking because I need this motor to last at least until I get another motor ready drop in.

 

[bigdan]

Ryan
you really have 16 lbs of oil pressure at cruising speed ( 1600 rpm at 60 mph with 2: 56 ratio) ( you have little over 10 lbs at 600 rpm in drive maybe , but shoulndt have below 20 lbs at 800 rpm ....

then your engine is loosen up ....

20 lbs at cruising is low ...period

buicks & amc had lo oil pressure at idling because they had a long travel to do because pump is in timing cover ....and it creates a lo oil pressure at idling but picks up at 30 lbs off idle ...
Dan

 

[ryanwitski]

okay i disagree. here is what my engine reads. cold start up high oil pressure (30-45) and stays there until low idle. when it gets up to operating temp and the electric fans are running (aka operating temp) it runs at about 12-15 lbs at 800-850 rpm.

cruising at 65 (1200 rpm it runs at about 30) but afterwards idles at 12-15 psi at idle. all of that is perfectly fine.

My Elky ran 30-40 psi at 3,000 rpm going 65. it was fine, ran great and still does. read around and look at other cars, running such a high pressure really is not needed in every circumstance.

 

[Chevyman85]

A SBC will idle low. If I run 5w-30 I'm at about 5-10 PSI at Idle (Hot) and 35-45PSI at Cruise. At opperating temp. theres noting wrong with low PSI. Just because you don't have a ton of oil pressure doesn't mean that is insufficient oiling.