engine bottom end construction

Question 1

what are engine cylinder blocks normally made out of

Answer 1

cast iron or alluminum

Question 2

a – cylinder block dissipates heat better than an —- block

Answer 2

aluminum better than cast iron

Question 3

many vehicles use —- blocks to reduce weight and increase fuel economy

Answer 3

aluminum blocks

Question 4

an —- is relatively thin and is not exposed to engine coolant

Answer 4

dry sleeve

Question 5

an — is exposed to engine coolant and must withstand combustion pressure and heat without the added support of the cylinder block

Answer 5

wet sleeve

Question 6

define line boring

Answer 6

refers to a machining operation that cuts a series of holes through the block for the crankshaft main bearings

Question 7

an —- main block only uses two cap screws to secure each main bearing cap to the —–

Answer 7

two bolt and cylinder block

Question 8

— mains are used on high performance engines

Answer 8

four-bolts

Question 9

a — provides clearance between the piston and the crankshaft counterweights

Answer 9

slipper skirt

Question 10

define piston diameter

Answer 10

the distance measured across the sides of the piston is piston diameter

Question 11

what is meant by the term pin hole diameter

Answer 11

the distance measured across the side of the piston pin hole

Question 12

define ring groove width

Answer 12

the distance measured from the top to the bottom of the ring groove

Question 13

a —- piston is slighty out-of-round when viewed from the top

Answer 13

cam ground

Question 14

what is the purpose of piston taper

Answer 14

used to maintain the correct piston-to-cylinder clearance

Question 15

—- generally refers to the countour of the piston top

Answer 15

piston head shape

Question 16

the head of a — piston is parralell with the blocks deck surface

Answer 16

flat top

Question 17

define valve reliefs

Answer 17

valve reliefs are small identations either cast or machined into the piston crown to provide ample piston-to-valve clearance

Question 18

automotive pistons normally use — rings, —- compression rings and — oil ring

Answer 18

3, 2, 1

Question 19

the — prevent pressure leakage into the crankcase and wipe oil from the cylinder walls

Answer 19

compression rings

Question 20

explain ring seating

Answer 20

its the inital ring wear that makes the ring perfectly match the surface of the cylinder

Question 21

name the two basic oil ring designs

Answer 21

rail spacer, one-piece

Question 22

what is the function of a pistons oil ring

Answer 22

to keep crankcase oil out of the combustion chambers

Question 23

the piston — is the distance from the top of the ring to the bottom of the ring

Answer 23

ring width

Question 24

piston ring — is the distance from the face of the ring to its inner wall

Answer 24

radial wall thickness

Question 25

piston --- is the distance between the ends of the ring when installed in the cylinder

Answer 25

ring gap

Question 26

when are soft ring coatings desirable

Answer 26

its reccomended for cylinders that are slightly worn/ forms a good seal

Question 27

hard ring coatings, such as ---- are used in new or freshly machined cylinders that are perfectly round

Answer 27

chrome or moly

Question 28

what are piston pins normally made of

Answer 28

case-hardned steel

Question 29

----- is a heating and cooling process that increases the wear resistance of the piston pin

Answer 29

case hardeneing

Question 30

a press fit piston is forced tightly into the connecting rods ------

Answer 30

small end

Question 31

an --- piston pin is secured by snap rings and is free to rotate in both the rod and piston

Answer 31

full floating

Question 32

what is the purpose of piston pin offset

Answer 32

locates the piston pin hole slightly to one side of the piston centerline

Question 33

an --- on the head of the piston is frequently used to indicate piston pin offset and the front of the piston

Answer 33

piston notch

Question 34

most connecting rods r made of

Answer 34

steel

Question 35

explain low intertia parts

Answer 35

low interia parts are light parts thatll accelerate quickly

Question 36

what is the purpose of a hole machined through the entire length of a drilled connecting rod

Answer 36

its to supply oil in the piston pin

Question 37

----- are used to ensure proper location of each connecting rod in the engine

Answer 37

connecting rod numbers

Question 38

define powdered metal forging

Answer 38

refers to a process that forms the rough shape of a part out of metal powder before final shaping in a powerful forge

Question 39

what are engine crankshafts usually made of

Answer 39

cast iron or forged steel

Question 40

turbocharged or diseal engines are normally equipped with crsnkshafts made of

Answer 40

forged steel

Question 41

oil enters the crankshaft at the --- and passes through holes in the main bearing journals

Answer 41

main bearings

Question 42

with a v-type engine ---- connecting rods bolt to each rod journal

Answer 42

two

Question 43

an --- crankshaft has weights formed oppisite the journals in the center portion of the shaft only

Answer 43

partially counterweighted

Question 44

---- is the bearings ability to withstand poudning and crushing during engine operation

Answer 44

bearing load strength

Question 45

--- is the bearing ability to adjust to imperfections in the journal surface

Answer 45

bearing conformability

Question 46

--- refers to the bearings ability to absorb dirt , metal, or other hard particles

Answer 46

bearing embedability

Question 47

--- is the bearings ability to withstand being acted on by acids, water, and other impurties in the engine oil

Answer 47

bearing corrosion resistance

Question 48

what is the purpose of bearing crush

Answer 48

used to help prevent a split type bearing from spinning inside its bore during engine operation

Question 49

----- is used on split type engine bearingsto hpld the bearing in place during assesmbly

Answer 49

bearing spread

Question 50

an --- bearing has the original dimensions specified by the engine manufacturer for a new, unworn, or unmachined crankshaft

Answer 50

standard

Question 51

an undersize bearing is designed to be usedon a crankshaft journal that has been machined to an ---- diameter

Answer 51

smaller

Question 52

connceting rod and main bearings are avaible in undersizes of

Answer 52

0.010, 0.020,0.030,0.040

Question 53

----- or dowels position split bearings in their bores

Answer 53

bearing locating lugs

Question 54

how are engine bearings lubricated

Answer 54

the holes allow oil to flow through the block and onto the clearance between the bearing and the journal

Question 55

what is the function of a main thrust bearing

Answer 55

limits crankshaft end play

Question 56

describe the purpose of a rear main bearing oil seal

Answer 56

prevents oil leakage around the block of the crankshaft

Question 57

name three types of rear main bearings oil seals

Answer 57

two piece neoprene seal, one piece neoprene seal and a wick or rope seal

Question 58

an --- rear oil seal is simply a woven rope filled with graphiyte

Answer 58

rope or wick

Question 59

---- means that some engine parts are selected and installed in a certain position to improve the fit or clearance between parts

Answer 59

select fit

Question 60

---- are used in some engines to cancel the vibrating forces produced by crankshaft, piston, and rod movement

Answer 60

balancer shafts