MDT Engines Chapter 4 review questions

Which of the following types of pistons uses bushingless pin bosses?

c. Monotherm

Technician A says that when using Plastigage to measure main bearing clearance, the larger the squish dimension, the greater the clearance. Technician B says that when measuring bearing clearance it is important to rotate the engine through one full revolution after clamping the Plastigage strip into position. Who is correct?

d. neither A nor B

Under which of the following conditions would a piston ring seal most effectively?

d. high cylinder pressures

Which of the following crankshaft journal surfaces hardening methods provides the highest machinability margin?

d. induction hardening

After removing the main bearing cap after checking bearing clearance with the specified color-coded Plastigage, the nylon strip has failed to deform. Which of the following is likely to be true?

a. excessive bearing clearance

Where would you likely find a Ni-Resist insert?

a. upper ring belt, aluminum trunk piston

Technician A says that keystone rings are the most common in current diesel engines. Technician B says that keystone conrods have a wedge-shaped small end. Who is correct?

a. Technician A

What is the upper face of a piston assembly know as?

a. crown

What type of piston is favored by diesel engine OEMs in recent commercial vehicle diesel engines?

b. forged steel trunk

Which term is used to describe the cylinder volume between the piston upper compression ring and its leading edge?

b. headland volume

What should you use to measure rod and main journal bearing clearances?

c plastigage

Which of the following would be most likely to occur if an engine was run under load with a failed vibration damper?

d. crankshaft failure