Which tool combination is used to check cylinder head for twist and warpage?

• A. Steel straight edge and feeler gauges
• B. Torque wrench and socket
• C. Caliper and micrometer
• D. Dial indicator and gauge

Answer: (A)

The key idea is checking the cylinder head for flatness, to detect twist or warp that would prevent a proper seal. A steel straight edge provides a true reference plane across the head surface, and feeler gauges measure the small gaps between the head and that straight edge at multiple points. By sliding the straight edge across the head and recording the gaps in several spots (often along different directions), you can see if the surface deviates from true flatness and by how much. If any measured gap exceeds the specified limit, the head is warped and typically needs machining or replacement.

Torque wrench and socket won’t assess surface flatness, since they’re for applying fastener torque. Caliper and micrometer measure dimensions rather than overall surface flatness. A dial indicator can measure runout or warp with the right setup, but the standard, widely taught method for cylinder heads is straight edge plus feeler gauges because it directly reveals any twist or warp across the head surface.