Exhaust Gas Temp Questions

[DeputyDawg]

I have been wondering what exhaust gas temps are in the combustion chamber itself assuming you have an egt in the pipes of 1200-1350F. The reason I am asking is because aluminum starts to melt at 1220 degrees yet we are not all out there melting pistons all the time(well most of us anyways). I suspect that the pistons just don't see that amount of heat as a constant, meaning that temp is the highest at combustion(momentarily) then the piston is traveling down and away from the explosion and is then being cooled by its next phases before combustion again.

[STV_Keith]

EGT measurement is an average temp. Think of the amount of time that the exhaust valve is closed compared to when it is open in all 4 strokes. Combustion temps are in the 2400*+ range.

[Mighty Thor]

aluminum starts to melt at 1220 degrees yet we are not all out there melting pistons all the time(well most of us anyways).
Right, but we are not running pure aluminum pistons either, they are all an alloy mix which raises the melting temp depending on what else is in the alloy. Still, I have seen pistons melted in the center just cause the wrong spark plug was used and the heat at that spot kept building until Splat, liquid piston.