Ignition timing refers to the relationship between when the spark occurs and the position of the which component?

• A. Crankshaft
• B. Camshaft
• C. Piston
• D. Connecting rod

Answer: (A)

Ignition timing is about when the spark plug fires relative to where the piston is in its cycle, and the natural reference for that is the crankshaft position. The crankshaft directly tracks the piston’s location as the engine turns, so timing is expressed in crank-angle degrees—usually a few degrees before the piston reaches top dead center on the compression stroke. The camshaft controls valve opening and closing, not when the spark fires, so it’s not the referenced component for ignition timing. The piston and connecting rod are part of the motion that the crankshaft governs, but ignition timing is defined by the crankshaft’s position.