Oil Pressure

[sealacamp]

Hey guys any advice on oil pressure? I just put a remanufactured engine in my truck, got about 250 miles on it and it seems that the pressure is low to me. I sent it back to the builder and he said he has examined it and is satisfied with the lubrication of this engine.

It has a stock oil pump, it's a 350, has about 30 to 32 PSI cold but drops off a good bit to about 10 or so when hot. I was thinking about putting a high volume pump in there just to make sure that there is plenty of oil flowing, should be a 20% increase in oil flow according to the book. The original engine developed bad crank bearings, a friend of mine gave me an engine and it developed catastrophic valve train problems in 4 weeks, now I'm running good but I want to keep it that way. Any advice or opinions are greatly appreciated.

Thanks wondering what I should do if anything.

 

[skysurfer]

10 psi @ warm idle is acceptable. You should see around 10 psi per 1000 rpm, so as long as pressure builds with engine speed you're ok.

 

[sealacamp]

Well it is building with engine speed but once warm I'm getting about 25 PSI. I just think this is a bit low for a new engine and over time it will drop as the engine wears. Maybe best to wait until I see a drop then switch to a HV pump?

I've got a 70 LeMans with 45,000 on a remanufactured engine it was about 75 to 80 PSI out of the box and drops to about 20 PSI idle when hot but right back up to 80ish when rpms rise. It's lost about 8 psi or so around the 40,000 mile mark. Maybe I shouldn't be comparing these two engines but that new chevy is far below where my pontiac is.

 

[Skweegle89]

25 at warm idle is fine. I just put a new crate motor in and I'm not getting much more than that.


Sent from an old rotary telephone.

 

[sealacamp]

The 25 psi I'm getting is not at idle, that is driving speed, don't know what my RPM's are though. About 10ish PSI hot idle and 25ish PSI hot driving speed. So you guys think this is acceptable oil pressure for a new engine?

 

[350runner]

A high volume oil pump will help with your low oil pressure issue. It will also prolong the life of the engine. I'd put one on. In fact i have one on my engine and m my 100 degree day hot idle oil pressure is 25psi.

Sent from the dust in front of you!

 

[yevgenievich]

I have high volume on mine, but the recommendation that i have heard is to run high pressure, not high volume pump. High volume can empty the sump too quickly and usually need a deep sump oil pan. My hot idle pressure is around 30-35 and 60+ as soon as rpms rise a bit. This is on a refreshed motor(bearings/rings). Tho motor in the suburban with 130k miles is 30 psi hot idle and 45-60 driving around.That one is all stock

 

[350runner]

High volume oil pumps are good to use. Just make sure the drain back passages are clear and you won't have issues.
High pressure oil pumps will require loose clearances. You will ruin the bearings on the center journals.

Sent from the dust in front of you!

 

[sealacamp]

I think that the clearances are loose now, otherwise a stock pump should give me a bit more pressure than I'm getting. That's why I figured that a HV pump would work well. On my Pontiac I believe they put a HV pump on it when it was remanufactured and it has held pressure better than any engine I've ever seen or had. Since this Chevy engine is new it is clean inside so there are no constrictions to be concerned about. Not sure if I really need a deeper pan or not, I'll have to look into that. Since I'm not even out of break in period I want to do something to secure the life of this engine before it starts to develop any problems.

 

[350runner]

A high volume pump will give you the results you are looking for. No worries about needing a deeper pan.

Sent from the dust in front of you!

 

[sealacamp]

Thank you sir 350 that is what I'll be doing in addition to adding an oil cooler. I appreciate everyone's feedback!!

Have a great weekend all!

 

[350runner]

Your welcome.

Sent from the dust in front of you!

 

[highdesertrange]

I always run a high volume pump. my current rebuild is 15 years old and not easy miles either. make sure to change the intermediate shaft too. make sure the new one has a steel sleeve that replaces the nylon one. highdesertranger

 

[jetman]

I have a very old and tired 305. When working it hard in the summertime the idle oil pressure is ~ 5 psig, running down the freeway hot returns ~ 15 psig. Has been running this way about 2 years, I am always a bit nervous.

Presently running 10-40 lube but considering going to 20-50 in the summer to try and pump things up a bit.

 

[350runner]

Factory or aftermarket gauge?

Sent from the dust in front of you!