To the PM...details are off the top while having my coffee and IIRC...
Normal combustion temperature in the CC for a gasser runs around 250*F to 500*F
Higher for performance gassers and even higher for forced fed gassers
Melting of aluminum alloy is around 800*F to just above 1,200*F and pure
alu is around 1,200*F
Melting point of cast iron is round 2,000*F
Pre-ignition/knock temperatures can be around 1,800*F to 2,000*F, so high enough
to melt either metals...but there are other thermal attributes working here
Thermal inertia (both to hold and move it around...path ways) will not allow
the liner or piston get that hot on just one pre-ignition/knock cycle...
There is also a boundary layer of air/fuel molecules between the flame front
and the metal surface. Normal flame front that is and with pre-ignition/knock
it is much, much faster (shock wave effect) that causes other areas within the
CC to explode (not burn like a controlled ignition combustion) that will have
those molecules next to the metal surface EXPLODE to cause another shock wave
going back to the original shock wave to collide
Marry that EXPLOSION with the higher temperatures from pre-ignition/knock...it
can and will melt either or both metals inside an ICE CC (combustion chamber)
Thermal expansion characteristics has different rates for each one,
but that area will have to actually look up, as that was never a
study area of mine during college strength of materials classes
This is the simplified explanation of how pre-ignition/knock can and does
destroy ICE's
If the metal is not melted, then the damage from those shock waves can and will
crack (over stress) metal surfaces and into their thickness...to blow holes
into stuff
