what is a normal oil pressure for a big block....540 na 700 hoarse

I am guessing but would think anything in the 40's is fine with 15W-50 M-1 once warmed up at cruise.

what is your oil pressure? are you running an electric or mechanical gauge?

im in the 50"s but when i run it hard for a few minutes it drops to 40 im putting a oil temp gauge in today and trying it again, i have ran mechanical and electric they both stay the same.......



sorry phil i could not wait i bought a 540......awsome boat ran 79 on gps first time out in heavy chop

On my 540 since it was built (5 seasons ago) it has never had more than 35-36lbs running, and around 25 idleing. I've freshened it a couple of times and the bearings always looked like new. This is on a mechanical guage with 20/50 Amsoil racing oil.
I know the oil pump is fine, and on a test rig the oil pump is putting out 65lbs. I know the problem is in the crank. It is an Eagle and when we first assembled it the Radii on the rod journals were to large causing the rods to be way to tight. Now after having it fixed I have the opposite problem, low oil pressure. So other than replacing the crank or having it welded and reground I just deal with it.

my 509 with v-twin oil runs 75-80 psi cold and about 55-60 at warmed up cruise. Idle is about 40-45 warm. Oil temp runs 220-270 after a hard run. (oil pan temp)

Take 1 qt out of the pan. If this cures the problems then you have a windage issue. The crank is whipping up the oil causing the oil to be hotter and become aerated.

I shoot for 80 psi cold, 70-80 psi at WOT. Idle hot should be 30-40 psi with 25W50 Pennzoil Racing. Oil clearences need to be set up correctly.

With my 540s, the oil pressure usually runs about 60 when cruising. Drops backs to around 40 at idle. The oil temps will run up to 190 after a hard run.

Ok Mines Not A 540 Just A Modified 454 And My Oil Pressure At Idle Is 35 To 38 And Never Goes Over 42 Even After A Run. Is This A Problem? I Have Always Figured 10 Psi Per 1000 Rpm