What a great video Peter, thanks for sharing that. Notice how the Camel rocked back and forth when he was warming up the engine? Tell ya though, I'd rather listen to that Merlin per than that Gnome fartin'.
Aviation Museum in South Australia have an "Engine Running Day" twice a year or so. Last one I attended, they had a Gnome - active in WW1 - 100 years old obviously, a Merlin, PRatt & Whitney, a small jet too.
To actually see the engines running was

, the sound, the smell, the looks - all worth it, a unique experience.
The Gnome was indeed a strange one, you can see the whole engine rotating while the shaft itself doesn't, the guys presenting it demonstrated the speed control, it was exactly that sound that appears in the video. Now imagine having to switch the ignition on and off to control your speed, wipe your goggles off with the scarf so you can actually see something, and on top of that, trying to fire the machine gun that would jam more often than not.
THe Pratt & Whitney was nicknamed OLD SMOKEY and everyone soon found out why.
THe Merlin was a bit moody on the day. Wouldn't start at first. 20 minutes of priming, praying, cursing, and all that seem to have done the trick and it started. I am still getting goosebumps remembering the sound of that engine
THe little jet engine was a 2 minutes job - push the starter button, monotonous sound, the guys said "This is a little jet engine, always starting, always working, always reliable - very boring" :woohoo: :woohoo: :woohoo:
I got some pics, will post them later.