Very low oil pressure after complete rebuild

[Craig]

Hi folks,

 

My ‘52 L6 has been completely rebuilt.  It starts and runs great. However, I only have 2 lbs of oil pressure, corroborated by an independent gauge (my gauge is newly rebuilt). I removed the oil pump, filled it in an attempt to prime it, and reinstalled it. I double checked the relief valve assembly which looks correct. Prior to rebuilding, the block was magnafluxed and dipped by a reputable engine shop. 
 

I would really appreciate any and all suggestions or thoughts steering me to a resolution. 
 

Thanks,

Craig

[kencombs]

The only thing that comes to mind, other than mismatched bearings and crank,is the oil delivery tube from the pump side to the oil gallery.   Bad fit or not tightened?

[P15-D24]

Did you replace the cam bearings?

Did you plastigauge the main bearing while doing the assembly?

[Craig]

P15 - Thanks for responding. All cam and crank bearings were replaced and crank straightened by the engine shop. I called them and they double-checked the clearances in their record of my rebuild. 

[Craig]

Ken - I installed the pick up and screen, but I’m not certain about the pump-side delivery tube. If I can’t debug this from the outside, I’ll drop the pan and take a look. Thanks 

[P15-D24]

How are you measuring the oil pressure, stock gauge or external gauge? 

[Craig]

P15 - Both. A reconditioned stock gauge and an external independent gauge hooked separately to the same line. The external gauge showed 2 lbs. 

[Dave72dt]

Check your rotor/gear to end cap clearances in the pump.  Too much clearance no means low or no pressure.

[Dodgeb4ya]

Possibly the oil pu float limit tangs are bent letting  the float rise too high....

To Test.....add an extra quart or too of oil.

Imediately normal 40+ lbs of oil pressure should show.

[Craig]

On 12/4/2022 at 11:11 PM, Dodgeb4ya said:

Possibly the oil pu float limit tangs are bent letting  the float rise too high....

To Test.....add an extra quart or too of oil.

Imediately normal 40+ lbs of oil pressure should show.

Hey guys - I’m remiss for not getting back to you earlier. My problem was resolved as @Dodgeb4ya had suggested, but for a different reason. I added two quarts of oil and the gauge registered 30 lbs at idle. Unbeknownst to the tech at the restoration shop, my dipstick ferrule was loose on the stick, allowing it to drop lower in the case, indicating 5 quarts, when there was actually only three. Phenomenally simple issue. Thanks to all.