I've seen several answers now that refer to "pinking" in what can only be a detonation context. I've heard of knocking referred to as "pinging," but never "pinking." So is this a typo that should be corrected, or is it a valid term?
It is a perfectly valid and common term.
Perhaps this is a UK v US thing. Certainly over here, it has been called Pinking since time immemorial.
I had always taken it to be onomatopoeic. Pinking describes the sound much better than pinging.