When is fuel injected into a cylinder of...

Question 1 / 270705eccefa1bacbc34ba4d473be

Question 1 of 270705eccefa1bacbc34ba4d473be

When is fuel injected into a cylinder of diesel engines?

Question 1 of 27070

When is fuel injected into a cylinder of diesel engines?

🔍 Key Concepts

• Four-stroke diesel engine cycle (intake, compression, power, exhaust) • Relationship between air compression and temperature rise in a diesel engine • How diesel ignition differs from gasoline (spark-ignition) engines

💭 Think About

• First, mentally walk through the four strokes of a typical diesel engine and identify what is happening in the cylinder during each stroke. • Ask yourself: at which point do we need very hot, highly compressed air for the fuel to ignite without a spark? • Consider whether fuel should be present while the air is being compressed, or only after the air reaches a very high temperature.

✅ Before You Answer

• Make sure you know which stroke is the compression stroke and what the piston is doing during it. • Confirm that in a diesel engine, fuel is not used to compress the air; only air is compressed first. • Verify that auto‑ignition (self‑ignition) of diesel fuel depends on spraying fuel into already hot, compressed air.

Question 1 of 27070

When is fuel injected into a cylinder of diesel engines?

Before air in the cylinder is compressed.

After air in the cylinder is compressed.

After combustion gases in the cylinder have expanded.

As air is taken into the cylinder.