Just wondering who can solve my oiling mystery on a 426 cid mopar perf crate motor I have.I realize it will have to be torn down but wondering if the hemi experts here know where the trouble will be.
So manually spinning the oil pump with a drill,the motor makes great pressure at tdc(and every 90 degrees after that) but as I turn the crankshaft past TDC it loses all pressure at approx 45degrees past TDC (and every 90degrees after that).
Pulled valve covers and confirmed I have oil at the rockers so pressure is good up top .Before I pulled valve covers I was thinking maybe a rocker shaft plug was missing and there was a huge leak causing pressure loss when top end is oiled.
Also I have the intake manifold off the motor and no obvious large leaks to be seen anywhere around lifters etc.

I'm thinking this is a common issue and not worth worrying about. The engine runs and sufficient oil is fed to the heads when the cam is spinning. If you leave the engine feeding the heads and not turning it over what would you expect? It will pump the pan dry. Oil at temp returns to the pan much easier. I've never checked that the pump will suck the pan dry. Just seems logical as the engine needs to run to oil as it should. I turn the engine over to make sure the heads are getting oil properly then I turn it so they don't and look at the pressure then I'm done. You can feel the drill load when it's pumping.

I've had a similar problem with a early(1966) street hemi motor with a sold roller cam in it, it would pulse the oil pressure while running
Turned out to be the left lifter galley hole (drivers side) was machined a tiny bit lower than the passenger side allowing the roller lifters to expose the bottom of that oil galley at or near max lifter lift loosing oil pressure momentarily so I ended plugging the driver side off with two welsh plugs(1/2 inch maybe ) by driving them into the oil galley past the cross over passages at the rear of the block
BTW the first one must of moved and starting letting the oil pressure pulsate again and the second one installed behind the first one stop that
Have you tried priming the motor with the intake off and look for leaking around the lifters yet? If not maybe you should
Good luck , let us know what you find

I ain't a Hemi expert but anytime psi is dropping to zero would trouble me (I'd keep digging).

So this problem ended up being an issue with the crankshaft,something I have never seen before.the oiling holes from the mains to the rods are drilled right out the side of the crank throws.there are supposed to be threaded plugs at the end of the holes but they were never installed.So oil heading for the rods was just shooting out the sides of the crank throw instead.Im installing plugs and replacing all bearings even though the rod bearings look surprisingly good,mains were not as good!

The crate Hemi engines had a lot of quality problems but that one is a first for me. I'm surprised that engine lasted as long as it did. You are lucky that it didn't eat itself into little tiny chunks. I've only worked on one crate Hemi and it was a pile of garbage. Just about everything was wrong with that engine. Wrong parts, wrong clearances, etc. A high school shop class could've built a better engine.

Wow...sadly typical of MP stuff though. Glad you found the issue and that it was a relatively easy fix...now go buy a lottery ticket!

This is probably recoverable in civil law for the entire cost of the engine. Regardless of the (non) warranty, there is always an "implied warrant of use" in which the thing must be capable of performing the task for which it was sold.

does that even have a thrust bearing?

After a little over 8 years working with that stuff, I thought I had seen it all.

Wrong.

My first thought:"what the hell is that???"
Nope, never seen that before.

The picture shows it is not a World block, so I'm going to guess it must be a Cummins abortion.
Maybe from the very end, when they knew the
axe was about to fall.

2007/08 is about the newest it could be...that's a long time ago, and as far as I know nobody there is empowered to
do anything for anybody these days..... I comped as many folks as I could with parts during my tenure
but had that capability cut off more than once.

I'm pretty sure if you call 'em up, these days you'll
get my ol' buddy working from home in his underwear...he doesn't send anything out.

Cummins never painted the inside of the timing cover, the crate engines had cheesy chrome.
Has it been apart?

What does the exterior of the engine look like?
Is the Cummins/MP yellow tag still intact, at least?
Cummins also stamped the block with various codes, but the Chrysler engineer who dealt with that no
longer works for Mopar. And the Cummins rep/engineer who handled it no longer works for Cummins.
But......if any of it can be documented, esp. the purchase, that would be a good start if you wanted
to see if you have any recourse. Probably not, but the worst they can say is no.

Ive never seen a hemi crank before with those type of holes in the throws??
the thrust bearing is perfect,the only bearing that was truly obviously hurt was #2 main.
the bearings were all dated end of 2009 1st month of 2010 so maybe it is not even a crate motor as I was told?
The front counterweight on the crank has "keith black ,marathon, 3.750" stamped into it.There are #s stamped into the top pad as well that I will post later.
Maybe the engine was only driven in a show/trailer queen type car and never saw any real load or RPM's ? I really dont know any history on it.........

I've seen a lot of Mopar stock type cranks with the front and rear rod journals drilled out all the way as well as some not drilled out all the way like yours.
Are you sure the oil passage from the mains is not offset to that rod journal?
I reread your original post and the symptoms act like a lifter causing the pulsating oil pressure

I've seen KB billet cranks that had a plug like that. And they would be stamped KB on the front.