[MustGoFaster]

Well, I actually think there's a typo in that second to last paragraph. He says 45% throttle, but think he meant RPM. If you go back and read the paragraph before it He says 3250 RPM, wich is just a little over 45%, but he also says "during this period high throttle openings should be used". I wouldn't consider 45% high throttle.

In an engine, the forces that HP/TQ apply to the components pails in comparison to the forces of accelerating and decelerating the rods an pistons at high RPM. By limiting the RPM you eliminate those forces, by using high throttle you put the cylinder pressure behind the rings to press them onto the cylinder walls before they develop the glaze and are no longer "abrasive" to the rings. That's just my interpretation based on the above quote and this one:

"However the engines run with throttle restrictions saw a marked difference in the spot hardness and sealing faces of the rings and bores, which was attributed to the reduced load applied to the engine preventing satisfactory bedding of the rings and the bypass of combustion gasses past the rings. This had caused localised overheating and contamination of the bores, pistons and rings."

Basically I get high throttle(seat the rings with cylinder pressure), low RPM(keep forces low) and heat cycles (work hardening).