what are these "det cans" often mentioned in knock sensor threads ?
don't reckon most would be doing this to theirs, but this guy claims, "Detonations are heard clear crystal!"
I'm aware of the electronic 'listener' like this
http://autospeed.drive.com.au/cms/A_0353/article.html
but....horsham site (I believe it was) used to have details on how to go about making a simple device for 'hearing' detonation. I think is began with something along the lines of, "hammering flat the end of a length of half inch diameter copper tube, bolted to the engine block.... ".
Anybody saved or is familiar this procedure/method. Can't find it there any longer.