As engine RPM is increased from idle speed...

Question 1 / 27070

Question 1 of 270705eccefa1bacbc34ba4d4737a

As engine RPM is increased from idle speed to full load speed, which of the conditions listed will decrease?

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Question 1 of 27070

Q

As engine RPM is increased from idle speed to full load speed, which of the conditions listed will decrease?

🔍 Key Concepts

• Behavior of lube oil pressure as engine speed and load increase • Difference between design characteristics (like compression ratio) and operating conditions (like pressures and mixtures) • How fuel and air demand change from idle to full load

💭 Think About

• Which of these options is fixed by engine design and does NOT normally change just because you advance the throttle? • Think about what your lubrication system pump does as RPM goes up—would that make pressure go up, down, or stay the same (within normal limits)? • As you add more fuel for higher power, what typically happens to the proportion of air to fuel and to peak pressures in the cylinder?

✅ Before You Answer

• Identify which items are mechanically fixed (do not vary with RPM under normal operation). • Recall the general trend of lube oil pressure vs. RPM on a healthy diesel engine. • Consider whether cylinder peak pressure at full load is normally higher or lower than at idle.