FAA Powerplant Written Practice Test

In what location (flow sequence) on a reciprocating engine is the main oil filler located?

1. Before the oil pressure pump

2. Just after exiting the oil pressure pump

3. At the oil cooler entry

4. After the oil filter

The correct answer is: Just after exiting the oil pressure pump

The main oil filler in a reciprocating engine is typically located just after exiting the oil pressure pump, which is crucial for a couple of reasons. First, this placement allows for the proper circulation of oil throughout the engine once it is pressurized, facilitating efficient lubrication of engine components. The oil pressure pump is responsible for moving oil from the sump to the various components that require lubrication. By positioning the filler after the pump, it ensures that the oil being added will be directed back into the system where it can be distributed effectively and maintain appropriate pressure levels throughout operation. Additionally, if the filler were positioned before the pressure pump, then any oil added would not be immediately available for circulation, as it would need to go through the pump before entering the lubrication system. Similarly, placing the filler at the oil cooler entry or after the oil filter may not be optimal because it could create complications in the circulation path, potentially leading to ineffective lubrication or increased resistance in the flow system. Thus, the location just after the oil pressure pump is ideal for maintaining efficient oil flow and distribution in a reciprocating engine.