The salvage tug to which you are assigned...

The salvage tug to which you are assigned has main engines fitted with intake and exhaust systems as shown in the illustration. Assume that the typical cylinder exhaust temperature at 75% of maximum, continuous rated load is between 850° and 900 F. What will happen to the typical cylinder exhaust temperature when the load is increased to 100% of maximum continuous rated load? Illustration MO-0076

🔍 Key Concepts

• Relationship between engine load and cylinder exhaust temperature on a turbocharged diesel • How fuel rack position and air supply from the turbocharger change as you go from 75% to 100% load • The temperature values in the illustration: cylinder exhaust, pre‑turbine, and stack temperatures

💭 Think About

• When you increase load on a diesel, what happens to the amount of fuel burned in each power stroke, and how does that affect exhaust gas temperature? • Look at the pre‑turbine exhaust temperature range shown. Is it higher or lower than the cylinder exhaust temperature range at 75% load, and what does that suggest about temperature trends with increasing load? • Would an engine designer expect peak rated load to run cooler, the same, or hotter than a reduced load if everything is operating correctly?

✅ Before You Answer

• Compare the given 75%‑load cylinder exhaust temperature (850°–900°F) to the pre‑turbine exhaust temperature (1000°–1050°F) and note which is higher. • Think about whether more load = more fuel burned per cycle, and whether that typically makes exhaust gases hotter or cooler in a properly adjusted diesel. • Eliminate any option that suggests exhaust temperature behavior that would be unsafe or uneconomical for a diesel engine at its maximum continuous rating.