This chart shows melting points of various metals.
https://www.steelforge.com/literatur...elting-ranges/
Here's some excellent reading on the warping of engine blocks. It seems that fr the block to actually warp it must be heated to an extremely high temperature. There is no doubt that the deck surfaces must be checked first.
https://www.google.com/search?q=does...hrome&ie=UTF-8