🔍 Key Concepts

• Forced-feed lubrication system operation and purpose of the sump/reservoir • Meaning of residence time (how long oil stays in the sump before recirculating) • Relationship between oil level, cooling time, and oil temperature before it re-enters the system

💭 Think About

• If the oil level in the sump drops but the pump flow rate stays the same, what happens to how long each “portion” of oil can sit and cool in the sump? • Does a smaller volume of oil heat up and cool down faster or slower than a larger volume, assuming the same engine load? • How would shorter or longer residence time in the sump affect the temperature of the oil as it is pumped back into the engine?

✅ Before You Answer

• Be clear on what residence time means: is it related to the volume in the sump, the pump flow rate, or both? • Think about whether a lower oil level gives the oil more or less time to release heat in the sump before being recirculated. • Check which option correctly pairs shorter vs longer residence time with hotter vs cooler discharge temperature from the pump.