block filler

Deanster: "Fill" is a concrete-like substance marketed as a cylinder stabilizer kind-a-thing. It's a powder mixed w/ water and poured into the water jackets to assist in keeping the cylinders round under duress. It's to help maintain cylinder pressure. I can't think of the brand names used. W/ a block on a stand, one cyl. bank is leveled while it's poured in. After it sets, the other cyl. bank is leveled and process is repeated. Streetability depends on how high the jacket is filled and I guess, a bunch of other factors. In a race block, we used to fill them to the freeze plug level. I believe the block must be honed, if not bored and honed, afterwards. (Because the stuff will move the bore around. ) I don't remember the specifics.
Years ago, I read that Bob Glidden built his engines on the floor because he thought the stress from hanging on an engine stand would distort the bores. This was before "fill". (As far as I know.) I'd love to talk w/ him about engines and performance theories. What about the stress of a drag launch w/a solid mounted engine? Seems those cylinders would be moving around some. I raced a bit of stock eliminator, and these were the kinds of things my partner and I would talk about. How much beer we drank affected what we remembered!