Let's play "Guess what's wrong"

[allencr267]

Blocked filter?
Never worked on what you got, but it'd be very rare for an engine Not to have a filter bypass, or a spinon filter not to have its own. A light spring to open up if the pressure difference is more then about 5PSI.
Guesses? Sorry, I got none.
Good luck.

[Mummert]

Start from ground zero.

Cut the filter apart, that will show if anything in the engine is going away.

The things that come to mind are the oil pump bypass is stuck open, the oil pump pickup is loose or has a cracked weld, a piece of silicone/teflon tape is blocking the oil pressure sender, the gauge is bad. Oem blocks have an oil passage crossover that is sealed with a 1" or so plug at the back of the lifter valley, Its very common to epoxy those plugs after installation.
Seeing the its an after market block it probably doesnt have a main girdle. Oil pumps have to be carefully clearanced around main girdles, very easy to have the pump not seat correctly or put a hole in the pump body.
It could be simple it could be a real issue you just have to find it. GOOD LUCK.

[Caprimaniac]

Thank you all. I am returning some results...

Oil filter opened & inspected- clean- which mean that the black stuff (coating from brearings) never reached the oil fikter. Yes- bypass-type filter.

I did a VERY interesting experiment. After inspecting oil pump, drive and pickup <i assembled on the engine and used a plastic conteiner with engine oil held under the pickup & had a friend driving the pump from above.
It took a while- and 1/2 gallon of oil before the oil started squirting out between the rods & sides of the main bearin saddles.... It poured, rained hard. So, that is where the oil is going. After 2-3 quarts of oil, I finally got oil to the top end too. So, not blocked.

All plugs are screw- in. I have not found anyone leaking, no.

Why was the bearing coating wiped off?

Maybe some softer material- like paper- if left in oil channels. Wiped the coating and left no trace behind it, so it left no witness marks on bearings?
Could it be a leak, givin not enough oil to bearings, making the coating go? Cam retainer plate?

A bit sorry about not giving more detailed dexscription in thread title. Cannot be undone now!

I'll probably get engine out and inspect even more in a week.