Do you know the back ground of the engine?? You stating that the front oil relief bolt just kept spinning leads me to believe that is was tampered with. I would do what RE mentioned and drop the pan. Maybe someone pulled the spring and piston for some strange reason. Without it oil will bypass before it ever makes it to the rear iron.

 

or you can just disconnect the master oil output port from the front housing and see if any oil squirts out when you're turning the engine over. If you have no oil coming out, your pan and front housing must come off, so let that guide you.

 

Easier to take the oil filter off lol

 

I had this happen to one of my builds once. I cranked for probably 10 minutes off and on and filled every hose I could think of with oil and nothing... I packed the pump with Vaseline (name brand of course). I never disassemble the oil pump. I just remove the 10mm bolts and pull the chain off. I then just said screw it and let the engine start for maybe 1/2 a second and cut it off. I then had oil up to the filter. I'm sure many will gawk at the idea, but I'm almost 5000 miles into the build with 110 PSI and no issues!

As long as you used plenty of lube putting it together and you squirt some fresh oil into each chamber when you turn it over it should be fine letting it start for a 1/2 second. Just don't rev it any more than it wants to naturally.

 

mostly its about how long you crank it, if you only crank it for 5 seconds then that will never prime the pump. the oil it may have accumulated will just fall back to the pan.

when i prime the engine i crank it for a good 30 seconds or so until the oil pressure gauge moves off 0 and the cranking tone changes of the engine, spinning slightly faster. it's rare i have to check the filter with that method.

 

This was on a 1980 for me, so no gauge unfortunately. Being it's a SE keg with amenities I'll probably add a gauge inside. Every other build I've done (mostly 12A) I just cranked for 30 seconds and loosened the oil filter to see a little oil pour out.