Things were going great right up until they didnt...

And I probably should have

 

Here is a link to the video showing idle oil pressure with cool oil during very first startup

 

It was likely not cleaned thoroughly enough before assembly. Even the slightest amount of shavings will wreak havoc..

The rest of the bearings will tell the story.

 

You managed to have 70PSI of oil pressure at the some stage, meaning a wrong (weak) oil spring relief is not the case.

In spite of all variables and combination effects related to "oil pressure" (testing temperatures, viscosity index, etc), it sounds like excessive bleeding somewhere would have increased over time - where and why? Many possibilities already speculated here - cam bearings, cracks, contamination - the lot

As suggested by JW, it is prudent to systematically test the oil system before disassembly the engine to ascertain the problem - otherwise you may risk not finding it when all is apart again... Prime the pump with a driver and see (manifold removed to facilitate a top view as well) where it eventually leaks in excess. If nothing obvious is found, suggest pulling the oil pump apart first and seeing any excessive clearances (not only bottom of gears, but for scoring of housing itself which would result in reduced pressure build capability).

Cheers/Alex

 

Im not a machinist, but I believe your clearances are NOT the issue.
I keep looking at your oil temps verses your coolant temps, verses your oil pressure.
What is making that oil so hot?
On run #8 @ 3500 rpm you had 36.6 lbs
At 5900 rpm your pressure only increased 11.9 lbs
Your pressure should have rose at least 25 to 30 lbs
I'd be looking at the oil pump, and pick up tube.
The pump isnt able to keep up for some reason.
Even with thinned oil from heat, I would ASSUME the pressure relief would stay closed until the pump produces the rated spring pressure.
Also check your FILTER bypass, if its stuck open it will drop oil pressure.
https://www.v8buick.com/index.php?attachments/20210202_153917-jpg.508213/

 

That would have concerned me, only 70 lbs at 2500 rpm cold/cool oil.
Running the pump with a drill I've been able to produce over 100 lbs and watched the oil filter balloon outwards
IIRC, the red spring is the 70 psi spring.

 

Mark mentioned checking the filter bypass. Would it also be worth cutting the filter open to see what was going in there at the time? And how about the oil pump pickup screen and tube? Everything looked normal there?

 

Scott,
I assume at the 8 second mark on the oil hemmorage test video, the dipstick fell back into the motor?.. there is something that shoots down just behind the pickup tube on the other side of the motor, but I don't think it is a stream of oil. If it is oil, then just found your cause for low oil pressure. I would guess something going on with a cam bearing/housing or a broken block..

I any event, judging from the streams of oil shooting out of every main, it's time to take the motor apart and inspect the rest of the rod bearings, and the mains, and see what they tell us.

I will be interesting to first see how the rest of the bearings look, and then how round the main housings are.

Also.. stock timing cover?.. unless it's NOS, check carefully the shaft to housing clearance on the drive gear.. That is usually what condemns and old timing over when I check them. There is no easy way to fix that.

 

I cant comment on the root cause of this other than to say I fully agree with Jim when it comes to a rear oil feed line.

My 455 will never see more than 5000rpm in service but I still went with the rear feed mainly because I'm having to use a remote twin filter setup and wanted to make sure I had as much oil pressure as possible where it's needed.

The pressures below were taken off of the filter manifold which you can see here

 

Yes, that was the dipstick dropping back down.

Stock timing cover, I saw only very little oil coming up around the shaft at the pump

 

The results of the oil flow test are that: just drips from the valve retainers, 14 of the lifters just drip, however 2 have a pencil lead thin drool of oil at the lower outer of the lifter. Very little from the cam bearings, they are still in place and cant visually see any block cracks. The lions share of flow is from the main cap parting lines, especially 2,3, and 4. Rod caps don't seem to have any streams, just good drips.

Will pull the engine down tomoro or Saturday

 

Haven't gotten the crank out but I took all the caps off. All the other rod bearings look new still. The crank rod journals look great also.

The lower main bearings look fine on 1 and 2. 4 looks bad and is showing copper. 5 is worn and can feel roughness. The crank main journals look great on 1 thru 3. 4 and 5 show some wear but nothing catches a fingernail. If 4 and 5 check out still round with no taper and are a tenth or 2 within their original size, I will just leave the main journals alone.

I didn't visually see and cracks in the main webs, but the crank is blocking some areas.

Will check rod and main housings when I get the crank out.

 

The balance line to the rear galley will be in version 2.0 of this motor. In addition to improved oiling to the rear, I like it for the benefit of reducing the load on the pump; since the pump is now having to supply more volume, the pressure (and force needed to turn it) will be lower. I've only learned this since the motor was finished, and then read Jim's excellent write up.

 

The crank mic'd fine otherwise, with only a tenth or 2 difference from where it started out.

The main housings were measured and the vertical checked out ok with all between 3.438" and 3.439". However, #2, 3, and 4 were out of round by 8 tenths. It is very odd that they are wider at the parting lines, and some ok until very near the parting lines. You would think the stress would have enlogated the housings in the vertical direction.

At any rate I guess an align hone or line bore is needed.