Yes, they are. P&R R2800 radial. Nothing sounds that cool.
Nothing.
I had a B-17 fly over my house at around 300-500 feet a couple of years ago...I heard the engines, ran outside and it was coming right for me!!!!
I was in my backyard, jumping up and down going WOOOOOOOOOOOOOOHOOOOOOOOOOOOOOO! with my arms in the air!!
There is NOTHING like it.
What? I have a little hearing loss in my right ear, courtesy of the 4x 2800s aboard the DC-6.
You could tell the guy on the ramp doing spark plug changes on a DC-6 by the two 5-gallon buckets he carried, one for the plugs on the port wing engines, the other for starboard.