AERA Component Inspection & Quality Control 3

Question 1

A camshaft lobe lift measurement that is below specification by more than 0.005 in indicates:

Accepted Answer

Lobe wear requiring camshaft replacement

Answer

Significant lobe lift loss means the lobe profile has worn down, reducing valve lift and engine performance, requiring camshaft replacement.

Question 2

To check valve stem-to-guide clearance, a technician inserts the valve and rocks it sideways while measuring movement with a:

Accepted Answer

Dial indicator at the valve head

Answer

A dial indicator positioned at the valve head rim measures total side-to-side movement, which is then compared to the stem-to-guide clearance specification.

Question 3

What does a blued (heat-discolored) zone on a crankshaft journal indicate?

Accepted Answer

Overheating from oil starvation or bearing failure

Answer

Blue discoloration on a journal indicates it reached temperatures exceeding 400°F, typically caused by oil starvation or a spun bearing, compromising the journal's hardness.

Question 4

When inspecting pistons, which area is most critical to measure for diameter to determine piston-to-bore clearance?

Accepted Answer

Below the oil ring groove at 90° to the pin bore

Answer

Piston diameter is measured at the thrust face (90° to pin bore) near the skirt bottom where the piston is largest and controls bore clearance.

Question 5

Dye penetrant inspection (Zyglo) is used on aluminum and non-ferrous parts because:

Accepted Answer

Non-ferrous metals cannot be magnetized for mag-flux testing

Answer

Magnetic particle inspection requires ferrous metals; dye penetrant works on any material and is therefore the NDT method of choice for aluminum castings.

(AERA) Automotive Engine Rebuilders Association Certification Practice Test

(AERA) Automotive Engine Rebuilders Association Certification Practice Test

AERA Component Inspection & Quality Control 3