Lost oil pressure in my BBC 454 and fortunately caught it quick. Pulled distributor and can see the top of the shaft broke off into 2 pieces. Found 1 side with magnet. Can't get the shaft out with the magnet. I can turn it back and forth a little which leads me to believe the Mellings HV77 oil pump didn't seize. I used the hardened shaft that came with the Mellings pump. I built the engine with marine specs and this season was running Kendall 20w-50, other seasons ran straight 50w and will go back to straight 50w.
Engine has been running fine for about 6 years. Turns 6000-6200 rpm with jet drive. I did switch from a MSD Pro Billett distributor to a HEI about 10 hours of run time ago.
I double checked my clearance numbers and by the looks of the wear on the piece that broke off I was within 1/8" of bottoming out the connection.
Did I do anything wrong?
Obviously I have to pull the pan, find the other piece and check the bearings for wear.
My next thought now is auto shut off for oil pressure loss, not sure what that involves since I use a GoPro on my gauges for data collection.