🔍 Key Concepts

• opposed piston engine geometry (two pistons in one cylinder moving toward/away from each other) • How crankshaft timing affects when each piston reaches dead center • Meaning of inner dead center vs. outer dead center in opposed piston engines

💭 Think About

• Visualize one cylinder with two pistons: what does it mean if one piston is slightly ahead or behind the other in crank angle? • Which choice talks about a small difference in timing (in degrees of crank rotation) rather than speed or direction? • Focus on options that describe the relationship of each piston to dead center – which sounds like a lead/lag, not a completely different motion?

✅ Before You Answer

• Identify which options describe timing difference in crankshaft degrees rather than speed or rotation direction • Check which option uses inner/outer dead center in a way that matches two pistons in the same cylinder moving toward each other • Eliminate any option that does NOT mention a slight lead/lag in when dead center is reached