During a timing check, which parameter is measured by the timing disk?

During a timing check, which parameter is measured by the timing disk?

• A. Crankshaft rotation in degrees
• B. Valve lash
• C. Piston height
• D. Belt tension

Answer: (A)

A timing disk serves as a degree wheel that reads the crankshaft’s angular position in degrees during a timing check. By rotating the engine and noting where a fixed reference pointer lines up with the degree marks on the disk, you obtain the crankshaft rotation in degrees relative to a reference point (often TDC). This lets you verify ignition timing or valve timing precisely. The other options don’t fit because valve lash is the clearance between valve stem and rocker and is measured with feeler gauges; piston height isn’t determined from a timing disk; and belt tension is checked with a tension gauge.

A timing disk serves as a degree wheel that reads the crankshaft’s angular position in degrees during a timing check. By rotating the engine and noting where a fixed reference pointer lines up with the degree marks on the disk, you obtain the crankshaft rotation in degrees relative to a reference point (often TDC). This lets you verify ignition timing or valve timing precisely.

The other options don’t fit because valve lash is the clearance between valve stem and rocker and is measured with feeler gauges; piston height isn’t determined from a timing disk; and belt tension is checked with a tension gauge.