🔍 Key Concepts

• combustion timing vs. piston position during the power stroke • how peak cylinder pressure changes if most of the burn happens later in the stroke • effect of late burning on exhaust gas temperature as gases leave the cylinder

💭 Think About

• Visualize the piston motion: if fuel is injected later, where is the piston (going down or near bottom) when peak burning occurs, and how does that affect pressure? • If combustion continues late into the power stroke or even toward the exhaust stroke, what happens to the temperature of the gases leaving the cylinder? • Compare what ‘late’ timing would do to how much useful work is extracted from combustion versus how much heat ends up going out the exhaust.

✅ Before You Answer

• Be clear on what "late" injection means: fuel is injected after the ideal point near top dead center (TDC). • Relate earlier peak pressure with higher mechanical work vs. later burning with less pressure rise but more heat wasted. • Before choosing, ask: does this condition more logically give higher or lower peak cylinder pressure, and higher or lower exhaust temperature?