B-17G Flying Fortress engine start-up and taxi
EAA's B-17G Flying Fortress "Aluminum Overcast" starting 2-1-3-4 engines and taxiing out, shot from very close range without zoom so you can really hear those Wright R-1820 Cyclones rumble.
The high-pitched sound before number 2 engine is started at the beginning is the starter, once it engages, the pilot counts 10 prop blades and hits the primer switch until the engine catches.