AT101 MCQ

cast iron has about how much carbon content

3%

To lower and narrow a valve seat that has been cut at a 45-degree angle, use a cutter or stone of what angle?

30°

How many degrees of camshaft rotation are needed to complete the four stroke combustion cycle?

360

a DOHC V-6 has how many camshafts?

4

Valve spring inserts (shims) are designed to ___

Adjust the correct valve spring installed height

All overhead valve engines _________ .

Have the valves located in the cylinder head

Where is a multilayered steel (MLS) gasket most often used in an engine?

Head gasket

ultrasonic testing is used to test

cylinder wall thickness

siamese cylinder bores are

cylinders with no coolant passage between them

the block deck is the

top surface of the block

the thrust bearing surface is located on one of the main bearings to control thrust loads caused by ____

torque converter or clutch release forces

if lift and duration remain constant, lobe center angle decreases, ______

valve overlap increases

What are the classes of fire extinguishers?

Class A - General combustibles (cloth, paper, wood) Class B - Flammable liquids and greases (gasoline, oil, thinners, solvents) Class C - Electrical fires Class D - Combustible metals (powdered aluminum, sodium, magnesium)

Bearing ______ occurs when a bearing shell is slightly above the parting surface of the bearing cap.

Crush

The proper relationship between intake and exhaust valve diameter is ___

Exhaust valve size is 85% of intake valve size

Umbrella type valve stem seals ___

Fit tightly onto the valve stem

Horsepower is expressed in units of ___________ .

Foot-pounds per minute

What force causes a head gasket to be drawn downward during engine operation?

Intake stroke vacuum

which of the following is the most correct statement about the direction of engine rotation?

Most engines rotate clockwise as viewed from the front of the engine

some manufacturers recommend repairing integral guides with

OS stem valves

How many rotations of the crankshaft are required to complete each stroke of a four-stroke cycle engine?

One-half

The intake valve opens at 39 degrees BTDC and closes at 71 degrees ABDC. The exhaust valve opens at 78 degrees BBDC and closes at 47 degrees ATDC. Which answer is correct?

Overlap = 86°

Torque is expressed in units of ___________ .

Pound-feet

Dampers (damper springs) are used inside some valve springs to ___

Prevent valve spring surge

How to jump start a vehicle with a dead battery

Step 1. Bad car + Step 2. Good car + Step 3. Good car - Step 4. Bad car engine block or metal bracket on engine block.

What determines the stroke of an engine?

The shape of the crankshaft

piston ring gap should only be measured after

all cylinder work is done

Use new pushrods because ______

all the dirt cant be cleaned out the hollow center

A steel or copper wire used in a head gasket around the cylinder is called ___ .

armor fire ring

cast iron cylinder sleeves are either cast into the aluminum block during manufacturing or pressed into the aluminum block. These sleeves are not in contact with the coolant passages and are called _______ .

dry cylinder sleeves

A typical v-8 engine crankshaft has ___ main bearings.

five

if bearing to journal clearance is doubled how much oil will flow?

four times the amount

a gasket failure caused by the movement of dissimilar materials is

fretting

a splayed crankshaft ___

has offset rod journals

cylinder heads with four valves flow more air than those with two valves because they

have a greater open area increase the velocity of the air

If an engine at sea level produces 100 hp, how many horsepower would it develop at 6000 ft of altitude?

hp @ elevation = hp @ sea level - (0.03*elevation*hp@sea level)/1000 hp @ 6000 ft = 100 - (0.03*6000*100)/1000 = 82 hp

what other engine component may have to be machined if the cylinder heads are machined on a V-type engine?

intake manifold

which type of valve guide is most used in a cast-iron head?

integral

which type of connecting rod needs to be heated to install the piston pin?

interference fit

full floating piston pins are retained by

lock rings

what should be installed and torqued to factory specs before machining a block

main bearing caps should be installed and torqued to factory specs before machining a block

The purpose of casting steel struts into an aluminum piston is

more strength control thermal expansion

which timing chain type is also called a "silent chain"?

morse flat link

side clearance is a measure taken between the

piston ring and piston ring groove

if a crankshaft is ground, it must be ____

polished

some gaskets use a steel washer around each bolt hole. the purpose of this washer is to ___ .

prevent the gasket from being overly compressed

which component is not needed in a typical overhead cam engine

push rod

a warped aluminum cylinder head can be restored to service by

put in 500°F oven with shims under each end, cool it, machine it

which product requires no heat to remove?

red thread locker

cam ground pistons, as they warm up, take on which of these shapes?

round

which type of sealer is to be used on nonmachined surfaces?

rtv

engine blocks can be manufactured using which methods

sand cast or die cast

A hypereutectic piston has a higher

silicon content

a full-floating piston pin is held in place using

snap rings

a one piece oil pan gasket often uses ___ in the middle to add strength

steel

flat bottom valve lifters rotate during operation because of the ______ of the camshaft

taper of the lobe

technician a says that if the ring end gap is excessive, blowby gases can travel past the rings and into the crankcase. technician b says that piston rings usually include three compression rings at the top of the piston and an oil control ring below the compression rings. who is right?

technician a only

which type of oil seal must not have oil applied for it to work correctly?

teflon

which statement is true about surface finish

the rougher the surface, the higher the microinch finish measurement

the surface finish for the cylinder walls usually depends on

the type of piston rings to be used

Hydraulic lifters can make a ticking noise when running if _____

the valve lash is too loose

hydraulic lifters or lash adjusters (HLA) may not bleed down well and cause an engine miss if ______ .

the wrong sae rated engine oil is used

audi five valve

three intake two exhaust

When measuring a cylinder for wear, the most wear will be found at the

top of the cylinder

The block deck is the

top surface of the block

In a normally operating engine, intake and exhaust valves are opened by a cam and closed by ________.

valve springs

vvt intake and exhaust

vvt intake - increase low speed torque vvt exhaust - reduce exhaust emissions

Technician A says that a crankshaft determines the stroke of an engine. Technician B says that the length of the connecting rod determines the stroke of an engine. Which technician is correct?

✓ X A

a misaligned connecting rod causes what type of engine wear?

diagonal wear on the piston skirt

typical bearing to journal clearance is

0.0005" to 0.0025"

typical valve stem to guide clearance is

0.001 - 0.004 " (0.03 - 0.05 mm)

A valve seat should be concentric to the valve guide to a maximum TIR of ___.

0.002 in

cylinder head gasket surface variation as measured with a precision straightedge

0.002" in any 6" length 0.004" overall

Never remove more material from the tip of a valve than

0.020

a valve should be discarded if the margin is less than ___ after refacing

0.03

If an interference angle is machined on a valve or seat, the angle is usually ________.

1 degree

Many aluminum piston skirts are plated with

Tin or moly graphite

A rotating force is called ____________ .

Torque

Compression Test

1. Remove fuel pump and fuel-injection fuses. Disconnect main wire to coil and spark plug wires. Remove spark plugs. 2. Thread compression gauge in a spark plug hole. 3. WOT, crank 4 times. This should result in a stable reading. If not, crank up to 10 times, but do the same for each cylinder. 4. Note readings for each cylinder

the camshaft makes ______ per crankshaft revolution

1/2 revolution

How many degrees of CAMSHAFT rotation are needed for a piston to travel from TDC to BDC and return to TDC

180

a four cylinder engine fires a cylinder every ______ degrees of crankshaft rotation

180

A normally aspirated automobile engine loses about ____________ power per 1,000 ft of altitude.

3%

One cylinder of an automotive four-stroke cycle engine completes a cycle every _____________ .

720 degrees

The coolant flow through the radiator is controlled by the _____________ .

Thermostat

An SOHC V-8 engine has how many camshafts?

Two

A hypereutectic piston

Uses about 16% silicon Is a cast piston

What are the types of fire extinguishers and their usage?

Water - class A fires Carbon dioxide - class B or C fires Dry chemical - Class A, B or C fires

technician a says that the connecting rods should be marked before disassembly. technician b says that pistons are cam ground so that when operating temperature is reached, the piston will have expanded enough across the piston pin area to become oval shaped. who is right?

a

two technicians are discussing a hemi engine. technician a says that a hemi is an engine with a hemispherical-shaped combustion chamber. technician b says that all hemi engines are cam-in-block designs. which technician is correct?

a

A forged crankshaft has a _______ .

Wide parting line

Technician A says that replacement pistons can be of different weights from the original pistons. Technician B says that some engines use an offset piston pin to help reduce piston slap when the engine is cold. Who is right?

X ✓ B

technician a says that the block deck is the surface to which the cylinder head attaches and can be slightly concave-shaped. technician b says that core plugs are used to fill the holes in the block used for casting. who is right?

X ✓ B

the space behind the piston ring is called

back clearance

a bearing shell has a slightly larger arc than the bearing housing. this difference is called _____

bearing spread

a bedplate is located between the

bottom of the block and oil pan

the ratio of the volume of a cylinder with the piston at BDC to the volume of the cylinder with the piston at TDC is known as ____

compression ratio

which component listed below does not form part of the combustion chamber

connecting rod

the ________ converts linear motion of the pistons into rotary motion

crankshaft

a ______ can be installed in a cast iron block to repair a worn or cracked cylinder

cylinder sleeve