AG Mechanics CDE Practice Exam

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Prepare for the AG Mechanics CDE Exam with interactive flashcards and multiple-choice questions. Each question is designed to help you understand key concepts and improve your problem-solving skills. Increase your chances of success through structured exam preparation!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

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What is valve overlap?

Both valves are closed
Both valves are partially open
Both valves are open
Both valves are seated

The correct answer is: Both valves are closed

Valve overlap refers to the brief period in the engine's cycle where both the intake and exhaust valves are closed simultaneously. During this time, the piston is at the top of its stroke and both valves must be closed to create the necessary compression for the combustion process. This allows for better control over the air-fuel mixture and exhaust gases, optimizing engine performance. Options B, C, and D are incorrect because valve overlap does not involve both valves being partially open, both valves being fully open, or both valves being seated simultaneously. The correct answer is option A, where both valves are closed during valve overlap.