........And, maybe the higher mass of the big, heavy piston maintaining more momentum to combat piston bounce, Jon? Then they later implemented the inertia piston. I wonder, was the mass of the piston lighter, giving quicker acceleration and, maybe, higher efficiency, with the delayed "dollop" from the inertia piston there to combat the bounce? Seem to think that combatting piston bounce was the main raison d'être for the inertia piston.