[Henry Schmidt]

Always looking to one up the experts. It's cute AF.
The statement I made was inarticulate but correct. I should have said "cylinders" not just materials. The iron cylinder will always retain more heat than the aluminum cylinder and as soon as the iron cylinders lose their (air) cooling as in cool down mode, the heat from the cast iron cylinder will transfer to the heads. Not so with the aluminum cylinders. Heat travels from hot to cold and aluminum cylinder in the same environment as cast iron will always cool the heads better.