HD2 Diesel Engines Exam

Upon inspection a technician finds that the deck on the top of the block is warped by .004" (maximum spec. is .008") The block should be:

discarded

reassembled as is

'"draw filed" to level a bit better

sent to a machine shop for resurfacing

Correct! Wrong!

Upon inspecting liner counter-bores a technician finds that the bore seat is rough and pitted. The correct procedure is to:

install salvage sleeves

replace the block

use lower press fit liners.

re cut the counter-bore seat

Correct! Wrong!

A liner with excessive pitting on the outside liner surface, opposite the major thrust area would be an indication of:

casting sand deposits

cavitation

corrosion

water pump pulsations

Correct! Wrong!

Technician A says that liner protrusion is measured with the liner clamped down in the block. Technician B says that liner protrusion may be calculated by subtracting the depth of the counter-bore from the liner flange thickness. Who is correct?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

A semi-floating wrist pin is one that:

floats in the piston and is pressed into the rod end

floats in the rod end and is pressed into the piston

floats in both the piston and the rod end

is pinned to the piston and floats on the rod end

Correct! Wrong!

When using a ring groove wear measuring device for keystone ring grooves, if the device contacts the side of the piston.

the piston may be reused.

the piston should be replaced

the ring grooves should be re-machined

none of the above

Correct! Wrong!

Technician A says that when removing or installing the connecting rods and pistons from an engine you should cover the connecting rod bolts to prevent damage to the crankshaft. Technician B says that when removing or installing connecting rods and pistons damage to the piston cooler nozzles may occur if one is not careful. Who is correct?

Technician A

Technician B

Both A and B

Neither A nor B

Correct! Wrong!

Installation of a non-drilled lower main bearing shell in an upper main bearing bore will cause.

improper nesting of the tang

no oil to enter the main bearing

inaccurate plastigage measurements

the bearing set to "spin"

Correct! Wrong!

Witness marks on piston rings indicate:

which side of the ring faces up

where to place the ring gap

the wear on the rings

all of the above

Correct! Wrong!

Referring to engines and their Babbitt bearings, premature bearing failures are more often traced back to:

misalignment

corrosion

insufficient lubrication

contamination during assembly

Correct! Wrong!

Too little liner protrusion will often cause:

excessive compression

head gasket failure or coolant leakage

distortion of the heads machined surface

incorrect torquing of the head bolts

Correct! Wrong!

When measuring a cylinder for wear you should check for:

taper

out of round

scoring

all of the above

Correct! Wrong!

When honing cylinder sleeves you should:

wrap them with a rag and place in a vise

have another person hold them while you hone them

insert them in the block and hone them

cylinder sleeves should not be honed only replaced

Correct! Wrong!

When checking bearing clearances, plastigage is __________as the clearance increases.

narrower

wider

Correct! Wrong!

A technician removes a cylinder ridge to:

facilitate new ring installation

prevent the piston from striking the ridge

ensure proper piston to cylinder clearance

prevent ring groove damage on the piston

Correct! Wrong!

After overhaul, prior to engine start up, a technician should:

complete a through visual check

prelube the engine

provide a means of cutting off the intake air in the case of an engine run away

all of the above

Correct! Wrong!

An improperly installed cam bushing may result in:

a blockage in the lubricating system

early camshaft failure

engine block damage.

all of the above

Correct! Wrong!

Reducing the size of the main bearing caps and recruiting the caps and block in a straight line is known as:

counterboring

crankshaft rezoning

line boring

really boring

Correct! Wrong!

Technician A says that grit from improper servicing is a frequent cause of premature bearing failures in the field. Technician B says that after honing cylinder walls, cleaning with soap and water is an effective method in engine rebuild procedures. Who is correct?

Technician A

Technician B

Both A and B

Neither A nor B

Correct! Wrong!

Which instrument(s) should be used to measure the liner counter bore depth?

outside micrometer

telescoping gauge and outside micrometer

small hole gauge and outside micrometer

depth micrometer

Correct! Wrong!

Technician A says that crosshatch pattern is controlled by the speed of the stroke and the RPM of the hone. Technician B says that deglazing of a cylinder will remove its taper. Who is correct?

Technician A

Technician B

Both A and B

Neither A nor B

Correct! Wrong!

A technician finds a badly worn main bearing in the center position, all other bearings appear to be in progressively better shape toward each end. The most likely cause of this would be:

insufficient oil pressure

bent crankshaft

overheating

all of the above

Correct! Wrong!

After properly torquing the connecting rod bolts, what step can be taken to ensure the rod bearing has been installed correctly and the tangs are properly nested.

rotate the crankshaft over to be sure it will turn easily

rock the rod from side to side on the journal by hand

remove the rod cap and recheck the bearing

twist the rod on the crankshaft to feel the clearance movement

Correct! Wrong!

A cylinder liner with permissible amount of taper has had the ridge removed and has been deglazed. At which location in the bore do most manufacturers recommend that the new rings end gap be checked?

near the top

near the center

near the bottom

all locations are satisfactory

Correct! Wrong!

Excessive ring groove wear on a piston may cause:

excessive oil consumption

ring breakage

hard starting

all of the above

Correct! Wrong!

Piston ring groove wear accelerates when the cylinder wall are:

oval

tapered

honed

deglazed

Correct! Wrong!

When measuring camshaft bearing oil clearance on an overhead camshaft engine. Technician A says that "Plastigage" can be placed between the camshaft journal and the bearing cap. Technician B says overhead camshaft bearings may be made of aluminum and are inserts. Who is right?

A only

B only

both A and B

neither A nor B

Correct! Wrong!

In the figure below, what is being performed?

Removing a scratch in the bearing with crocus cloth

Using a special tool to remove the bearing insert

Measuring the thickness of the crushed Plastigage

Determining if the crankshaft journal has been machined

Show hint

Correct! Wrong!

Engines using pre-combustion chambers:

are more sensitive to grade of fuel used

are less sensitive to grade of fuel used

Correct! Wrong!

A wet cylinder sleeve is one that is:

pressed into the original cylinder bore indirectly in contact with the coolant

in direct contact with engine coolant

in contact with engine oil on the outside and coolant on the inside

none of the above

Correct! Wrong!

If the stroke on an engine is 6 inches, what is the throw?

two inches

three inches

four inches

six inches

Correct! Wrong!

Parent bore engines are those that have:

dry sleeves

wet sleeves

no sleeves, the cylinder is machined into the block

original sized pistons

Correct! Wrong!

As an engine crankshaft rotates, the lubricating oil between the bearing and the crankshaft is drawn into the high stress or pressure area. The principle used to describe this process is known as:

oil vacuum

oil wedge

film strength

viscosity

Correct! Wrong!

The formula-force X distance divided by time is known as:

power

torque

inertia

work

Correct! Wrong!

The stroke or amount that a valve opens is dependent upon

cam lobe lift and rocker arm ratio

cam lobe lift and camshaft speed

cam lobe lift and pushtube length

cam lobe lift and crosshead length

Correct! Wrong!

When measuring a cylinder a technician finds that the distance across the bore of a cylinder is greater when measured at 90 degrees to the crankshaft than it is when measured parallel to the crankshaft. This difference is known as:

out of round

taper

Correct! Wrong!

When measuring bearing clearance with plastigage:

crankshaft should be rotated

crankshaft should not be rotated

journal taper will not be evident

cap bolts do not need to be installed

Correct! Wrong!

An undersized connecting rod bearing is one that has a:

larger outside diameter and a standard inside diameter

larger inside diameter and a standard outside diameter

smaller outside diameter and a standard inside diameter

smaller inside diameter and a standard outside diameter

Correct! Wrong!

The purpose of the chamber at the top edge of the lower bore on an engine block using wet cylinder sleeves is to:

prevent cracks in bore of block

aid in machining of block

guide liner o rings into bore

guide piston into liner

Correct! Wrong!

A piston assembly consisting of a separate crown, skirt, slipper bushing, pin, and pin seal expansion plugs would be known as a _____________ piston.

cam ground

crosshead

billet

keystone

Correct! Wrong!

Technician A says that cam ground pistons have the narrowest diameter across the piston-pin bore. Technician B says that piston cooler nozzle aim is not important to piston cooling. Who is correct?

Technician A

Technician B

Correct! Wrong!

Upon inspection a technician finds that the deck on the top of the block is warped by .004" (maximum spec. is .008") The block should be:

discarded

reassembled as is

"draw filed" to level a bit better

sent to a machine shop for resurfacing

Correct! Wrong!

Upon inspecting liner counter-bores a technician finds that the bore seat is rough and pitted. The correct procedure is to:

install salvage sleeves

replace the block

use lower press fit liners.

re cut the counter-bore seat

Correct! Wrong!

A liner with excessive pitting on the outside liner surface, opposite the major thrust area would be an indication of:

casting sand deposits

cavitation

corrosion

water pump pulsations

Correct! Wrong!

Technician A says that liner protrusion is measured with the liner clamped down in the block. Technician B says that liner protrusion may be calculated by subtracting the depth of the counter-bore from the liner flange thickness. Who is correct?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

A semi-floating wrist pin is one that:

floats in the piston and is pressed into the rod end

floats in the rod end and is pressed into the piston

floats in both the piston and the rod end

is pinned to the piston and floats on the rod end

Correct! Wrong!

When using a ring groove wear measuring device for keystone ring grooves, if the device contacts the side of the piston.

the piston may be reused.

the piston should be replaced

the ring grooves should be re-machined

none of the above

Correct! Wrong!

Technician A says that when removing or installing the connecting rods and pistons from an engine you should cover the connecting rod bolts to prevent damage to the crankshaft. Technician B says that when removing or installing connecting rods and pistons damage to the piston cooler nozzles may occur if one is not careful. Who is correct?

Technician A

Technician B

Both A and B

Neither A nor B

Correct! Wrong!

Installation of a non-drilled lower main bearing shell in an upper main bearing bore will cause.

improper nesting of the tang

no oil to enter the main bearing

inaccurate plastigage measurements

the bearing set to "spin"

Correct! Wrong!

Witness marks on piston rings indicate:

which side of the ring faces up

where to place the ring gap

the wear on the rings

all of the above

Correct! Wrong!

Upon inspection a technician finds that the deck on the top of the block is warped by .004" (maximum spec. is .008") The block should be:

Upon inspecting liner counter-bores a technician finds that the bore seat is rough and pitted. The correct procedure is to:

A liner with excessive pitting on the outside liner surface, opposite the major thrust area would be an indication of:

Technician A says that liner protrusion is measured with the liner clamped down in the block. Technician B says that liner protrusion may be calculated by subtracting the depth of the counter-bore from the liner flange thickness. Who is correct?

A semi-floating wrist pin is one that:

When using a ring groove wear measuring device for keystone ring grooves, if the device contacts the side of the piston.

Installation of a non-drilled lower main bearing shell in an upper main bearing bore will cause.

Witness marks on piston rings indicate:

Referring to engines and their Babbitt bearings, premature bearing failures are more often traced back to:

Too little liner protrusion will often cause:

When measuring a cylinder for wear you should check for:

When honing cylinder sleeves you should:

When checking bearing clearances, plastigage is __________as the clearance increases.

A technician removes a cylinder ridge to:

After overhaul, prior to engine start up, a technician should:

An improperly installed cam bushing may result in:

Reducing the size of the main bearing caps and recruiting the caps and block in a straight line is known as:

Technician A says that grit from improper servicing is a frequent cause of premature bearing failures in the field. Technician B says that after honing cylinder walls, cleaning with soap and water is an effective method in engine rebuild procedures. Who is correct?

Which instrument(s) should be used to measure the liner counter bore depth?

Technician A says that crosshatch pattern is controlled by the speed of the stroke and the RPM of the hone. Technician B says that deglazing of a cylinder will remove its taper. Who is correct?

A technician finds a badly worn main bearing in the center position, all other bearings appear to be in progressively better shape toward each end. The most likely cause of this would be:

After properly torquing the connecting rod bolts, what step can be taken to ensure the rod bearing has been installed correctly and the tangs are properly nested.

A cylinder liner with permissible amount of taper has had the ridge removed and has been deglazed. At which location in the bore do most manufacturers recommend that the new rings end gap be checked?

Excessive ring groove wear on a piston may cause:

Piston ring groove wear accelerates when the cylinder wall are:

When measuring camshaft bearing oil clearance on an overhead camshaft engine. Technician A says that "Plastigage" can be placed between the camshaft journal and the bearing cap. Technician B says overhead camshaft bearings may be made of aluminum and are inserts. Who is right?

In the figure below, what is being performed?

Engines using pre-combustion chambers:

A wet cylinder sleeve is one that is:

If the stroke on an engine is 6 inches, what is the throw?

Parent bore engines are those that have:

As an engine crankshaft rotates, the lubricating oil between the bearing and the crankshaft is drawn into the high stress or pressure area. The principle used to describe this process is known as:

The formula-force X distance divided by time is known as:

The stroke or amount that a valve opens is dependent upon

When measuring a cylinder a technician finds that the distance across the bore of a cylinder is greater when measured at 90 degrees to the crankshaft than it is when measured parallel to the crankshaft. This difference is known as:

When measuring bearing clearance with plastigage:

An undersized connecting rod bearing is one that has a:

The purpose of the chamber at the top edge of the lower bore on an engine block using wet cylinder sleeves is to:

A piston assembly consisting of a separate crown, skirt, slipper bushing, pin, and pin seal expansion plugs would be known as a _____________ piston.

Technician A says that cam ground pistons have the narrowest diameter across the piston-pin bore. Technician B says that piston cooler nozzle aim is not important to piston cooling. Who is correct?

Upon inspection a technician finds that the deck on the top of the block is warped by .004" (maximum spec. is .008") The block should be:

Upon inspecting liner counter-bores a technician finds that the bore seat is rough and pitted. The correct procedure is to:

A liner with excessive pitting on the outside liner surface, opposite the major thrust area would be an indication of:

Technician A says that liner protrusion is measured with the liner clamped down in the block. Technician B says that liner protrusion may be calculated by subtracting the depth of the counter-bore from the liner flange thickness. Who is correct?

A semi-floating wrist pin is one that:

When using a ring groove wear measuring device for keystone ring grooves, if the device contacts the side of the piston.

Installation of a non-drilled lower main bearing shell in an upper main bearing bore will cause.

Witness marks on piston rings indicate:

Success!

Heavy-Duty Mechanic - Trucks & Equipment