Question 258Motor Plants - Assistant Engineer

The correct answer is B) opposed-piston engine. An opposed-piston engine is a type of diesel engine where the combustion chamber is located between the crowns of two opposing pistons, rather than a single piston. This design allows for a more compact engine with a higher power density compared to a traditional single-piston diesel engine. The other answer choices are incorrect because: A) a double-acting engine refers to a steam engine, not a diesel; C) a single-acting engine has the combustion chamber above a single piston; and D) a horizontal-acting engine is a general term that does not specifically describe the configuration of the pistons and combustion chamber.