[john charlton]

The hole is to lubricate the timing wheel and dipper tray as there is no hole in the casting like a Model A engine . The oil pump has a capacity to pressure feed the main bearings and lubricate the timing wheel and dipper tray at the same time. In my view the mains are pressure fed not gravity like a model A . The drive would lift a few thou if the system pressure reached a certain point high revs and cold oil . The proof of the pudding is someone somewhere has a pressure gauge on the gallery ,I bet it reads more than zero .

John in same place same weather .