Do you mean, egg shapped for the bearings on the block and rods or the crankshaft ?

I never heard about that.

Yesterday, I had a look on my previous pump which gave the same problem.

I saw the relief valve stucked at the mid way. What is wierd is I was still eable to move the piston with a screwdriver and it came back to the same position at the middle...

I think I will try to change the oil pump one more time with a full check and the core of the piston smoothed and lubricated. On the rebuilt of the engine of a friend, I already saw the piston missing. Fortunately, I am used to check if the pump works propelly before setting the engine in the engine bay.