🔍 Key Concepts

• Pre-combustion chamber vs. open combustion chamber design and how fuel is burned • Relationship between combustion smoothness, peak cylinder pressure, and thermal efficiency • Fuel injection requirements, especially atomization needs, for different diesel combustion systems

💭 Think About

• For each choice, ask yourself: is this commonly cited as a benefit of pre-combustion chamber engines over open chamber engines in diesel textbooks? • Think about what happens to pressure and heat when combustion is spread out over a pre-chamber, then passes into the main chamber—does that usually increase or decrease efficiency and peak pressure? • Consider which type of system is typically used on small, quieter, but less fuel-efficient diesels vs. high-efficiency, high-power diesels.

✅ Before You Answer

• Identify which features are classic advantages of pre-combustion chamber engines: smoother running? easier starting? less noise? lower peak pressures? • Recall whether pre-combustion chamber designs usually have higher or lower thermal efficiency than direct (open) injection engines • Verify which system typically needs better fuel atomization: pre-combustion chamber or open (direct injection) engines