. "103942952"@en-us . "the timing of ignition relative to the position of the piston in an internal-combustion engine"@en-us . . "105051088"^^ . . "lead"@en-us . . . "05051088-n"^^ . . "0"^^ . . . "0"^^ . . "spark advance"@en-us . "104779012"@en-us . . "spark advance"^^ . .