Oil pressure: At a loss

Hey guys, I'm finally posting a thread, because I've hit a wall on what to do next. So I'm having oiling issues. I get 40lbs at start up when it warms it drops to 0lbs. Not good... I tried a higher viscosity oil from 10w30 to 20w50 made a small difference (valvoline sr1 high zinc)
First I checked cam bearings . Replaced the front cam bearing with a TA dual groove. The timing cover was also replaced with a TA high pressure one. I've lifted the engine checked the pickup. It is primed. I'm hoping to not have to replace the bearings again as the engine is freshly rebuilt. I know everything was put in right, but I'm concerned now that the mains or rod bearings are a hair undersized. This has been a nightmare rebuild, But I'm not ready to give up and send the engine out.

 

Ugh

 

Did you or TA install pump in housing.

 

TA. The gasket is 0.002. The spring is 50 lbs. I am fairly sure it isn't the pump. Could be wrong but I've checked the gears and they're at the correct clearance.

 

Who did the rebuild? Did they set the bearings up for sbc oil clearances? If so there is your problem right there.

But just to make sure, try a different oil pressure gauge, make sure it is an mechanical gauge in good working order to check the pressure with. GL

 

Yes. With a 50 psi spring and 20w50 , your bypassing or dumping oil out somewhere if your only getting 40 cold. I would start with the relief valve. 20w50 can hide alittle extra bearing clearance. Did you use your old filter housing? Or new TA one? Any lifter noise? Run roughly? Could be a pushrod not in lifter cup

 

The Guage works. I've switched out the guage twice and it reads they all read the same pressures.

 

A local builder in Colorado did the machine work. Set to Buick specs.

 

The filter and housing is new WIX, and I've used both the TA oil pump housing and the OEM. Also I've rebuilt the top end. push rods are in and preload is set correctly.

 

I've used the TA pump housing with different springs. And an Oem pump housing with several springs.

 

Who's oil filter adapter . New? When you changed springs did you pull out valve?

 

Yes and both. The TA was stuck closed from when it was shipped. So I freed that. It is adjustable.I also tried the OEM one And I don't know what you mean by adapter. If you mean pump housing yes I've used both. And yes the relief valve is free.

 

This is filter housing. It only covers oil pump it's not the oil pump housing timing cover houses oil pump. Also did you install cam bearing as TA instructions or did you line up bearing holes with the block holes

 

Yeah that's what I thought you were talking about. The cam bearing is lined up at 3 and seven not 8 and 2.

 

I decided to tear down the engine. Again... I will let everyone know what I find. Thanks for the posts.

 

A thought here... You said you replaced the #1 cam bearing with TA's grooved bearing, is that the ONLY cam bearing that was replaced?
The reason I ask is I'm reading more and more on here people are just using the TA grooved bearing on #1 only, and using stock type or just keeping the rest of the originals in place.
The #1 bearing IS important in the way it delivers oil to the left bank of lifters, but the other TA grooved bearings are important also in the way the cam BEARING JOURNALS are oiled.
The factory bearings the oil is introduced at the 9 o'clock position, and has from 9 to 3 to hemorage out before the higher load position starting at 3 o'clock.
The TA bearings introduce the oil at 3 o'clock, right before the higher load, where its needed instead of being wizzed out at the top of the bearing.
This scenario is even worse with worn factory cam bearings.

 

Pulling engine out, take off intake, pull distributer, and run a drill with a makeshift oil drive. You should be able to see cam bearings and thru distributer hole if there's a lot of oil pressure loss and where. you may not need to pull crank or rods

 

Just a thought, oil journal plugs in place and not sunk to far into the block closing off the passage or to loose and bleeding pressure?

 

I had only replaced the front with a grooved cam bearing. I'm rebuilding all the bearings including undersizing the crank. Still cheaper than sending it out to have someone else do the work.