How does the oil filter plate on a Pontiac 400 engine work?

The plate is basicly just an adpter to mount the oil filter. The pressurized oil comes out of the block through the lower hole, passes through the filter, then returns to the block through the upper hole. The adapter also is the mounting point for the oil pressure sensor, and contains a bypass that allows oil to bypass the filter if the filter becomes clogged, or restricts flow excessively. Some race engine builders plug the bypass to ensure only filtered oil at all times. however, on a street driven vehicle, in the event of a clogged or internally collapsed oil filter the engine will receive little to no oil and result in serious engine damage.