Us real men who are used to marine engines don't call 'em big unless:
a) they have an integral ladder you use to climb up to the platform that runs around the engine at the cylinder head level;
b) they have doors in the crankcase so you can climb inside to look at the crankshaft bearings (checking the engine is stopped before doing this is considered 'soft').
Mind you, these engines are called 'high speed' if max revs is over 100rpm....
My days in the engine room / Main Control were spent with a pair of GM 12-567 Diesel Engines, they were only rated at 900hp, torgue? max rpm 744. Not quite as stressed as that 24 V71. Those are basicly two 12v71's coupled. The Swift boats ran 2 of the 12v71's one per shaft. I used to work on that stuff and the 671's and 6v53's.
That is real pretty, but a little small. The engines I work on, like the Mitsui-MAN B&W 7170 slow-speed diesel puts out 20,000 Hp at 90 RPM.
Like Angib says, there are doors and ladders in the crankcase to inspect and maintain the engine.
I like to stand at one end of the engine, while it is running and, keeping the cylinder heads in sight, look at the bulkhead on the other side of the engine room. You can see each cylinder head rise a bit as it fires, it makes a kind of wave effect that sweeps back and forth across the top of the engine. If you look directly at the cylinder heads, you can't see it.
