Question

Technician A says that when measurement of the cylinder bore is out of specifications, just install an oversized piston. Technician B says that 0.030" over and 0.060" over are two common piston sizes. Who is correct?

Answer 1

Technician B is correct in stating that 0.030" over and 0.060" over are common piston sizes. However, installing an oversized piston requires more than just swapping pistons; the cylinder typically needs to be machined to fit the new size.

Step-by-step explanation:

The question revolves around the correct procedure when dealing with a cylinder bore of an engine that is out of specification. Technician A suggests installing an oversized piston if the measurement of the cylinder bore is out of specifications, while Technician B states that 0.030" over and 0.060" over are two common piston sizes. Neither technician is fully correct in the broadest sense. When a cylinder bore measurement falls out of specification, simply installing an oversized piston is not always the appropriate solution. The cylinder may need to be machined to a larger size to accommodate the oversized piston, ensuring a proper fit and avoiding potential damage to the engine. Technician B is correct in stating that 0.030" over and 0.060" over are common oversized piston sizes available for use after machining the cylinder. These sizes indicate how much larger the diameter of the oversized piston is compared to the standard-sized piston.