Final answer:
Both Tech A and Tech B are correct in their methods for measuring valve stem-to-guide clearance. Tech A focuses on the importance of measuring at three vertical locations to ensure accurate assessment, and Tech B emphasizes using a hole or snap gauge to measure the guide diameter.
Step-by-step explanation:
The question pertains to the procedure for measuring valve stem-to-guide clearance in an internal combustion engine, an important aspect of engineering practices related to machinery maintenance and repair. Tech A suggests that the valve stems and guides should be measured at three vertical locations, which implies checking for consistency and wear at different points to ensure an accurate assessment of the stem and guide fit. This method helps detect any unusual wear patterns or tapering that could affect engine performance. Tech B proposes using a hole gauge or snap gauge for measuring the internal diameter of the valve guide; these are precise measurement tools designed to determine the diameter of small holes and thus enable the measurement of the internal clearance.
Considering both Tech A and Tech B's suggestions, they each describe legitimate and complementary components of the valve stem-to-guide clearance measurement process. Measuring at different vertical locations ensures the clearance is within tolerances throughout the length of the guide while using the appropriate gauge ensures that the exact internal diameter is recorded. Therefore, if the question asks which technician is correct regarding the recommended practices for measuring valve stem-to-guide clearance, the correct option in the final answer would be Both.