Air intake ports on an EMD cylinder, view from inside the airbox.
Lately I’ve been trying to learn new things, which has led me down into the part of the boat where I never venture much anymore since the days of doing underway engine room rounds are several years behind me. It’s really helping to make my hitch move along and it is finally removing the shroud of mystery surrounding marine engines that once had me totally intimidated.
Cylinder head: exhaust valves on either side of the fuel injector, timed by cams rolling against the camshaft. 20 cylinders in each engine on this boat.