On Saturday, January 6, 2018 at 8:40:13 AM UTC-5, wrote:
from SSA Clubs and Chapters:

.... I learned that there was no sound thermodynamic or metallurgical reasons for the practice.

That statement piqued my interest. Does anyone know what the metal alloy and heat treatment of these cylinder castings are?
From a metallurgical point of view, repeated heat cycling of any metal will fatigue it at the grain boundaries which ultimately will lead to a failure.. In gas turbine designs, high Nickel alloys are used to make the blades, nozzles and everything else in the hot gas path and even those experience thermo-cycle fatigue and cracking despite paying painstaking attention to lower the stress risers in the design.

Uli
'AS'