Originally Posted by
Drive Stainless
I am curious about what is happening here. The "block rot" holes that I have seen have occurred in the bottom of the deep, ~3/4"x3/4" square-shaped holes. The solution seems straightforward: cap the holes with some small squares of aluminum. But both you and Chris Williams explain that the oil will find a new place to leak from, as if the oil could blow through the cast aluminum like a stream of water through tissue paper.
Nevertheless, I am very confident that I could make this repair based on my experience TIG welding aluminum.