This engine had an oil pressure switch mounted on a Tee between the engine and the VDO oil pressure transmitter. This placed the switch and transmitter mounted out on an arm. Mass on a spring. The resultant vibration caused failure of the fitting flush with the case. You can see the remnants of the brass there in the hole above the yellow cap. It takes about 30 seconds to dump 100% of the oil overboard through an opening like this. The results are shown in the next two pics.