This is one of my favorite IL-2 aircrafts and that heavy engine sound is just choice!!! Steven do you know what that noise is supposed to be @ 0:52-0:54? I get the same thing too when I'm pulling up hard after a dive, it sounds like dishes being broken. Usually nothing bad happens (nothing broke off or anything negative) just sounds funky.
Snachito Structural connections under stress... That's what the sound's supposed to emulate, however with sad inaccuracy. Too high in volume and too high pitch. You're right when you say "broken dishes". Nothing bad will happen and that sound is perfectly normal. The only thing to fear is a violent pull up when going 500+ km/h or so... The plane can sometimes throw a wing off or some shit like that. Happened to me twice with that fast-like-Satan TA-152