Question 130Motor Plants - Assistant Engineer

The correct answer is A) seal against scavenge air leakage. The top gland where the piston rod exits the cylinder is designed to prevent leakage of the scavenge air from the cylinder. Scavenge air is the air used to purge the cylinder of exhaust gases during the engine's operation. The top gland forms a seal to keep this scavenge air from escaping, which would reduce the engine's efficiency. The other answer choices are incorrect because they do not accurately describe the primary purpose of the top gland. Option B is incorrect as the top gland does not prevent crankcase oil leakage. Option C is incorrect as the top gland does not maintain crankcase vacuum. Option D is incorrect as the top gland does not maintain crankcase pressure.