FAA Powerplant Written Practice Test

Where is the oil temperature regulator typically located in a dry sump reciprocating engine?

1. Between the engine and the fuel system

2. Between the scavenge pump outlet and the storage tank

3. After the oil pressure pump

4. Near the oil cooler

The correct answer is: Between the scavenge pump outlet and the storage tank

The oil temperature regulator is typically found between the scavenge pump outlet and the storage tank in a dry sump reciprocating engine system. This location is crucial for maintaining the optimal temperature of the engine oil as it returns from circulation back to the oil tank. In a dry sump system, oil is stored in a separate tank rather than within the engine itself, which allows for better control of the oil temperature and reduces the likelihood of oil starvation. The oil temperature regulator plays a vital role in this setup by monitoring the temperature of the oil and adjusting the flow to ensure it remains within a desired range. By regulating the oil temperature before it enters the storage tank, the system prevents excessive heat buildup and helps maintain the integrity of the lubricating properties of the oil. This strategic placement also ensures that any cooling effects from an oil cooler can be maximized before oil is returned to the tank. In contrast, other potential locations such as between the engine and the fuel system, after the oil pressure pump, or near the oil cooler do not provide the same direct control over the temperature of oil returning to the storage tank. These locations would not effectively manage the desired thermal regulation necessary for optimal engine performance.