Walter, the two generators on the poop deck were air-cooled Duetz. I'm looking at a picture of them now in a Caroline phonebook, Caroline, a story in photos.
They were air-cooled V12's. Can't tell from the photos if they were turbocharged. They have quite a highly-geared. belt driven fan in the Vee of the engine that sucks air in and then blows it out through the fins on the cylinders either side. The cylinders have fins much like a motorbike engine. There is metal cowling that contains and directs the air.
I think I have read that the Cummins, which I believe was a V8, was in the room whose exhausts exited in from in front of the bridge.
Paul, was this specifically a generator room, or was it the ship's engine room (for the engine that actually propelled the ship, -when it worked)?