Component Inspection & Quality Control Flashcards

When checking a crankshaft for straightness, which measuring instrument is used in conjunction with V-blocks?

Answer: Dial indicator

A dial indicator mounted over the crankshaft journal while it rests in V-blocks reveals runout (bend) in the shaft.

Which condition is indicated when a cylinder bore shows greater wear at the top of the ring travel than at the bottom?

Answer: Taper

Taper occurs because combustion pressure forces the rings hardest against the bore at the top of the stroke, causing more wear there.

A main bearing bore that measures larger on one axis than on the perpendicular axis is described as:

Answer: Out-of-round

Out-of-round (also called ovality) means the bore is not a true circle, with differing diameters at 90-degree angles.

Magna-flux (magnetic particle) inspection is primarily used to detect which type of defect in engine components?

Answer: Surface or near-surface cracks in ferrous metals

Magnetic particle inspection reveals surface and subsurface cracks in ferrous (iron-based) components by highlighting particle accumulation at flux leakage points.

What is the maximum allowable out-of-round condition for most production engine cylinder bores before reconditioning is required?

Answer: 0.001 in (0.025 mm)

Most manufacturers specify a maximum out-of-round of 0.001 in (0.025 mm); beyond this, boring or honing to restore roundness is required.

When pressure-testing a cylinder head for coolant leaks, what medium is typically used to reveal cracks?

Answer: Compressed air with the head submerged in water

Compressed air is applied to sealed coolant passages while the head is submerged; escaping bubbles pinpoint any cracks or porosity.

Which measurement confirms that a connecting rod has not been twisted (side-to-side misalignment)?

Answer: Rod twist checked on an alignment fixture

A connecting rod alignment fixture checks both bend and twist by placing the rod on mandrels and measuring deviation at the pin ends.