Upgrading to High Volume oil pump, issues?

[pauls340]

My oil pressure gauge always read and currently reads lower than I think it should. The oil pump is stock and at least 20 years old. Can I just replace it with a high volume unit which is supposed to push 25% more flow? Do I have to replace the intermediate shaft? Thanks

 

[moper]

If the engine is original and never rebuilt - sure. And yes, the intermediate shaft needs to be the MP one and the bushing should be replaced and properly sized to it.
But - what is too low for your comfort level?

 

[70aarcuda]

http://stores.precisionoilpumps.com/-strse-38/SB-Mopar-Billet-HD/Detail.bok

billet intermediate shaft

 

[C130 Chief]

The pressure relief spring, not pump volume controls pressure.

If your gauge reads lower than you think it should have you verified it's accuracy?

 

[pauls340]

Now that screwsup my head. Is that spring easy enough for a backyard mechanic to do? :violent1: The idiot gauge is reading about the 1/8th line in pic. No I haven't check accuracy.

 

[Mattax]

Issues: High Volume Pumps use taller rotors resulting in a pump hieght that sometimes interferes with the oil pan.

Need: If your analysis of the oil pressure under a variety of conditions points to worn bearings or similar situation where more Flow would help.
You can tee in a parts store mechanical pressure gage if you want to check the accuracy of the factory gage and sending unit.
The pressure should be fairly high at start up (oil cold).
Check the specifics in a shop book, but I believe the gage shows roughly 0 to 80 psi. So 1/4 gage at idle (600 rpm) would be 20 psi. With oil fully warmed up, that's fine. For every 10 mph the presure should increase about 10 psi. In other words at 60 mph, 50 - 70 psi is still normal. When you find the oil presure can't keep up, then you've got a problem with volume.

A higher pressure relief spring should increase pressure in the system at higher rpms if there is enough volumetric flow. A race engine built 'loose' often will need a high volume pump with higher pressure relief to keep the bearings and top fed with oil at high rpm.

 

[RustyRatRod]

General rule of thumb is 10 PSI for ever 1K or engine RPM. If you meet that criteria, leave it alone.

 

[Inertia]

My oil pressure gauge always read and currently reads lower than I think it should. The oil pump is stock and at least 20 years old.

That makes your guage over 20 yrs old, maybe sender too,,.

Factory guages are known to be more of a guide than an accurate guage.
The idea being if you are used to seeing the needle in a particular place, when it's lower than usual,, it's time to check the oil level, OR have the oil pressure checked with a mechanical guage, to VERIFY you even have a problem..

What happens if you go to the trouble of installing a new pump,, just to find the guage reads the same,, then you find out the guage is normal,, but your "feeling" was wrong..

Personally, I'd verify it's low,, and if it was, I'd run a heavier oil.. my .02