Question

7 multiple choice 1 point which combustion chamber is most commonly used by medium- and heavy - duty diesel engines? indirect injection swirl chambers prechamber injection direct injection 8 multiple choice 1 point detroit diesel two - stroke engines operate more smoothly than four - stroke cycle engines because: there are twice as many power strokes per 100 revolutions as with a four - stroke cycle. cylinder pressure during the power stroke pressure is increased. the power stroke has a longer duration. it uses intake air ports in the cylinder wall. 9 multiple choice 1 point in a four - stroke internal combustion engine, during which stroke does air charge the cylinder? power compression exhaust

Explanation:

• For question 7: Direct - injection combustion chambers are most common in medium - and heavy - duty diesel engines due to their efficiency and power output capabilities.
• For question 8: Detroit Diesel two - stroke engines have twice as many power strokes per 100 revolutions compared to four - stroke cycle engines, which contributes to smoother operation.
• For question 9: In a four - stroke internal combustion engine, air charges the cylinder during the intake stroke.

Answer:

1. D. Direct injection
2. A. there are twice as many power strokes per 100 revolutions as with a four - stroke cycle
3. Intake (not listed in options, but if we assume based on knowledge, the correct answer is intake stroke)