🔍 Key Concepts

• How airflow is directed into the cylinder on a turbocharged four-stroke diesel • The difference between turbulence created by intake design versus turbulence created inside the combustion chamber • What feature in the illustration is actually in the air path before it enters the cylinder

💭 Think About

• Trace the path of the intake air from the turbocharger/air cooler into the cylinder—where is the flow being turned or aimed to create a swirl? • Which listed component acts on the air before compression, and which ones mainly shape combustion after the air is already in the cylinder? • Look closely at the shape and direction of the passage just upstream of the open intake valve—what is it trying to make the air do inside the cylinder?

✅ Before You Answer

• Identify which choice is directly connected to the intake port/valve area in the drawing • Eliminate any options that primarily affect fuel combustion shape rather than the incoming air motion • Confirm that your selected feature would naturally create swirl or high-velocity rotation of the air as it enters the cylinder