I do love a good inertia starter noise - particularly when the engine is reluctant to start. Even better if it's a hand-cranked flywheel, but electric-motor driven flywheel like this one can sound cool too.
When it does (finally) fire on all cylinders, I swear I can smell this bastard through my monitor
By the time it spins up quick it’s doing around 150-180rpm and it will die-engage aroun 320rpm. That’s spinning around 12th a of reciprocating parts under compression.
That’s with 2 air starters and a lot of air at 30 bar pressure.