air-fuel ratio to temp

[Matthew Lee Franklin]

>their runs by.. The ones that have used a EGT have melted pistons before the
>thermocouple responded enough to register danger.

One of the things about knock is that when it happens, the EGT drops.  The 
vibrating gasses speed up the heat transfer to whatever is inside the 
chamber, i.e., piston, head, headgasket, and so on.  This heat loss shows 
up as lower exhaust temperature.  Maybe it's something else, but knock can 
be nasty.