Please explain your theory why cooling below the exhaust port may be causing piston seizures.
Not causing piston seizures with coolant under the exhaust, that is not what I'm leading to.
My early thinking, back when Eddie first came out with these cylinders, that the area under the exhaust port was solid aluminum & no coolant could get down under the exhaust port to remove heat from that area. Now though, after I've done the milling down into the base of the cylinder casting, we all can see coolant "can" get down into that area.
If the casting were solid, no cooling jacket under the exhaust, then the exhaust side of the casting, would to a greater extent have to run much hotter than one where coolant could get under the exhaust port.
If coolant can get to that area, it should be able to at least remove some amount of heat build up.
The whole idea of this testing on a ESR casting, was to see if I could mill out the area under the exhaust port to create a cavity, then bore passage ways on both sides to the upper part of the casting so coolant could get down under the exhaust. Only trying to make a good product better was my thinking. Never know till you try.
Neil