🔍 Key Concepts

• Four-stroke diesel cycle timing (intake, compression, power, exhaust) • The difference between injection, ignition, and combustion in a diesel engine • Terminology used to describe the short time interval between fuel being injected and actually starting to burn

💭 Think About

• Think about what physically happens right after fuel is injected into a hot, compressed air charge in a diesel cylinder. • Which term among the choices refers specifically to a time interval (a short delay) rather than the main burning or power-producing part of the stroke? • In diesel theory, what is the standard name for the brief period needed for fuel atomization, mixing with air, and reaching self‑ignition temperature?

✅ Before You Answer

• Identify which options clearly describe a time interval rather than an event like firing or detonation. • Recall the standard diesel engine term used in textbooks for the period between start of injection and start of combustion. • Eliminate any option that is more commonly associated with gasoline (spark‑ignition) engine timing rather than diesel self‑ignition.