The pilot valves in an air pilot starting system for a two-stroke/cycle, direct-reversing, main propulsion diesel engine are operated by either a ported distributor disc or a/an __________.

Correct Answer: Option D — individual cam for each pilot valve

Direct-reversing marine diesels utilize mechanical timing mechanisms. On large two-stroke engines, individual cams driven directly by the camshaft actuate the pilot valves to ensure precise starting air distribution matching the required ahead or astern rotational sequence.