Exam 19: Engine Lower End and Lubrication System Theory

While discussing bearing undersizes, Technician A says that undersized bearings are used when a crankshaft is reground. Technician B says that they are used on some new engines to compensate for errors in production. Who is correct?

Which of the following is LEAST-Likely true?

While discussing vibration dampers, Technician A says that four-cylinder engines usually have a pulley and a damper. Technician B says that four-cylinder engines usually have only a pulley and do not use a damper. Who is correct?

Journals that are offset from the main bearing journal centerline are called ____________________.

Bearing spread promotes better heat transfer and prevents the bearing from spinning in the bore.

The crankshaft assembly, the piston, and the rod are collectively referred to as the ____________________.

All of the following statements are true EXCEPT:

Briefly discuss the three sources that subject bearings to normal loads.

The bearing surface has three primary properties that make it suitable for use in an engine: embeddability, conformability, and fatigue strength. Provide definitions for each of these properties.

Compression rings are forced against the cylinder wall by combustion pressure at the top and back of the ring. What is the purpose of the second ring?

To test a moly or chrome ring to see if it is ductile iron, simply twist it. If it is regular iron, it will break in two.

The top piston ring is positioned as high as possible on the piston to increase piston slap, help ring durability, and lower emissions.

Which of the following statements is LEAST-Likely true?

Heavy-duty engines and some vintage automotive engines use replaceable cylinder bores, called wet or dry ____________________.

An imbalance of 1/4 ounce (7 grams, or about one sheet of paper) at a 4" radius on a rotating part will MOST-Likely create forces of:

What is the difference between ductile iron rings and steel rings?

The crankshaft is pushed forward in the engine by pressure in the torque converter or by the release spring pressure of the clutch. Forward and backward movement is called ____.

The part that will MOST-Likely be used to prevent the piston pin from sliding out and damaging the cylinder wall is the:

Inline engines often have each rod lubricate its own cylinder.

An aluminum piston expands at about twice the rate of the cast-iron block. What can be done to control this expansion?