For some reason I simply love to RTFM, if the M(anual) really is F(ine). This collection of locomotive manuals is an especially lovely trove of interesting (but essentially useless, to me) information.
For example, the service manual for 7FDL diesels lists all kinds of things that you need a pry bar for on this engine, like speeding up the engine (beyond the governor's limits).
Even cooler, though, are two-stroke diesels. Have a look at this clip of an EMD 645 starting up. A cold start and with the exhaust manifold disconnected, to me this thing sounds very much like a cat purring once warmed up. According to the manual that would be a 2300+ hp, 13 ton cat... Plus, an engine where you need a hoist to lift a single piston must be good.
Should reincarnation really be an option, then I'd like to deposit that I want to come back as a diesel engineer next time round :-)