Help with low oil pressure

[Ricks72Chlgr440]

My builder said to use 10w/30 but both the idle and higher RPM pressure was too low for me. I moved up to GP-1 15w/40 and that brought the idle pressure up to around 20 and the highway pressure to about 50. I also changed the pressure spring to the black hemi at the same time. Still using the standard (not high volume) pump.

Edit: I had my builder install the 440Source stroker kit for me. They never indicated what the bearing clearance was. For me to have such low pressure the main clearance must be north of .003. If I ever pull the engine I'll know, but for now the pressures are fine for my street driving.

 

[moparmike68]

My builder said to use 10w/30 but both the idle and higher RPM pressure was too low for me. I moved up to GP-1 15w/40 and that brought the idle pressure up to around 20 and the highway pressure to about 50. I also changed the pressure spring to the black hemi at the same time. Still using the standard (not high volume) pump.

Edit: I had my builder install the 440Source stroker kit for me. They never indicated what the bearing clearance was. For me to have such low pressure the main clearance must be north of .003. If I ever pull the engine I'll know, but for now the pressures are fine for my street driving.

Was that 20 psi idle at hot/running temp? Yeah I’m guessing that my bearing tolerances are probably the issue too. Not too sure how good my “builder was”?🫩 as I have no idea what he did or what tolerances were. I didn’t receive any paperwork from him regarding measurements/tolerances etc. He was an older guy and was probably winding down his game and didn’t care much.? My luck. I’ll be more involved next time I have work done! I’m hoping that the straight 40 weight will get me some more pressure.

 

[Ricks72Chlgr440]

Was that 20 psi idle at hot/running temp? Yeah I’m guessing that my bearing tolerances are probably the issue too. Not too sure how good my “builder was”?🫩 as I have no idea what he did or what tolerances were. I didn’t receive any paperwork from him regarding measurements/tolerances etc. He was an older guy and was probably winding down his game and didn’t care much.? My luck. I’ll be more involved next time I have work done! I’m hoping that the straight 40 weight will get me some more pressure.

Yes, 20 hot idle. I'd be concerned about running 40 straight weight oil since it does take awhile to flow when its cold. You don't want to delay getting lube to the engine. The 15w/40 works for me but you could also use 20w/50 if you're really concerned. At least the 15 I use or the 20 would flow oil faster cold than the straight 40!

 

[moparmike68]

Yes, 20 hot idle. I'd be concerned about running 40 straight weight oil since it does take awhile to flow when its cold. You don't want to delay getting lube to the engine. The 15w/40 works for me but you could also use 20w/50 if you're really concerned. At least the 15 I use or the 20 would flow oil faster cold than the straight 40!

I usually only drive the car when it is warmer: spring, summer early fall. I was concerned with the

Yes, 20 hot idle. I'd be concerned about running 40 straight weight oil since it does take awhile to flow when it’s cold. You don't want to delay getting lube to the engine. The 15w/40 works for me but you could also use 20w/50 if you're really concerned. At least the 15 I use or the 20 would flow oil faster cold than the straight 40!

Thanks for your reply. I just did a little more research and you are correct that the straight 40 is thicker at start up than say 0w or 15w. I do drive the car during the fall and there may be some “cold” start ups and the straight 40 would take longer to get to parts of the engine as you said. I don’t like that idea, but 0w and 15w are thinner at beginning, but retain the viscosity at 40 when oil is hot, therefore I think I am going to try the 15w40 instead of the straight 40. And see if my pressure increases.
Thanks again to all of your replies guys!

 

[moparleo]

Lets start with what should be obvious.
Is the oil pressure gauge giving you accurate information ?
Get another manual oil pressure gauge and install in the proper location and test again.
Don't rely on electrical gauges or sending units.
If you want to also have your dash gauge working, just use a "T" fitting for the sending units and plumb both.

A fail safe that Dodge used for years on their Vans was to install a oil pressure switch set for 10 psi and attached to the the Electric fuel pump power wire.
This would kill the pump if the oil pressure dropped below 10 psi.
Saves the engine from bearing damage

If you are replacing an oil dipstick and it is not marked or the tube is not standard length is simple.
Start with the filter removed and the oil pan dry. Starting with no oil.
Install the filter, add the proper amount of oil and start the engine.
Run for a few minutes and shut off.
Check oil level on stick in 10 minutes.
Mark the stick with a notch.
This is now the exact amount of oil that you put in.
Length of the tube or stick doesn't matter as you have just set the level with the exact amount of oil required.

 

[Chryco Psycho]

This could be a few things ,
I have seen some oils run low pressure & that is the easiest to change & see what the result is
I have also seen lifters with the oil groove around the body too low or high & bleed oil past the lifters when sitting low in the bores , this is also relatively easy to check , you could pull a lifter with a magnet & compare to a new lifter or different lifter .
The other possibility is the brg clearances were machined wrong & are too lose , you would have to pull the pan & drop a rod & or main brg to check . easy to test with plastigage .
You could also check to make sure the pick up tube is sealed & tight , if it is loose it could be pulling some air in .
Melling pump are very good & I doubt that is your problem