I recall slang years ago referring to a 6 cyl engine as a six-banger. I ***umed "bang" was the obvious gas igntion in the cylinder, six times.
Four Banger probably came about, as a term, shortly after 1931. As a side rant and in keeping with the current "belly tanker" thread, I dislike the term "banger". Traditionally, they were called four bangers. Another is "moredoor". That one gives me the runs.
I agree four banger is the traditional term, but I quite often see it shortened to banger, especially those of trog guys.
A four cly. has no over lap of power stroke. Bang - Bang - Bang - Bang. A 5, 6, 8, and 12 cly. can not do this. As compared to