We have torn down some engines before but not that nastly looking with heavy carbon build-up. Is that space surrounding the bores part of the water jacket, it is the first time I see that design in a petrol engine. I understand both the block and the head of Mirage are high grade aluminum alloy, with a sturdy bolt fastening design, I presume that it will take a higher overheat temperature before any of them are warped in contrast to a steel block with aluminum head unless tha all aluminum alloy engine is really not that strong.