In the context of end-gap measurement, which type of ring is specified for the measurement?

In the context of end-gap measurement, which type of ring is specified for the measurement?

• A. Spare
• B. Replacement
• C. Original
• D. New

Answer: (C)

End-gap measurement uses the ring that will actually be installed in the engine—the original ring. Measuring with the original ring provides the clearance reference that matches the piston’s design, bore finish, and ring material as it will seat in service. Spare, replacement, or other rings can have different dimensions due to manufacturing tolerances, so they aren’t the reference for this measurement. If the end gap isn’t within spec, you’d select a ring of the same original type to restore proper sealing and operation.

End-gap measurement uses the ring that will actually be installed in the engine—the original ring. Measuring with the original ring provides the clearance reference that matches the piston’s design, bore finish, and ring material as it will seat in service. Spare, replacement, or other rings can have different dimensions due to manufacturing tolerances, so they aren’t the reference for this measurement. If the end gap isn’t within spec, you’d select a ring of the same original type to restore proper sealing and operation.