you wouldn't really feel heat on the outside of the block, as there would be nothing to really transfer the heat. air is a good insulator, and water is a good conductor. I have a 216 block that has a crack right at the bottom of the cylinder, that had to be a heat induced, along with casting stresses. That is why I am saying crack, the cylinder would be exposed to a fairly high temperature, while the rest of the block would be relatively cool. Given what I have seen done by heat expansion/stress, that is where I would have to go. Not to mention there is really no other way for the water to get into the oil pan, they are pretty well separated.
