Question 366Motor Plants - Assistant Engineer

The correct answer is C) 10° to 20°F. The typical temperature increase between the inlet and outlet jacket cooling water of a medium or high-speed diesel engine operating at normal load is 10° to 20°F. This is because the cooling system is designed to maintain the engine at the optimal operating temperature, and a temperature increase in this range is considered normal and expected during normal engine operation. The other answer choices are incorrect because a 1° to 5°F increase (option A) would be too low for a medium or high-speed diesel engine, and a 50° to 100°F increase (option D) would be excessively high and indicate a problem with the cooling system or engine.