A great design, but it wasn't perfected until Packard Motor Cars, of Detroit, started manufacturing it. This fact is often lost on many Brits.
I took my young boys to a warbird museum near Warner Robins AFB. They had a Merlin on display with its casing sliced open to reveal its innards. My youngest son, about four years old, ducked under the ropes and put that engine in a loving embrace.
Momentarily, there appeared a staff member at my side who was obviously getting ready to scold us. Then he said, "I was here to tell you not to allow your children to go under the ropes, but I am not going to be the fellow to break up a nice love affair".