,note3 ,images ( ! orig9al pages are available ?r\gh ,int]net ,ar*ive4 ,see https3_/_/ar*ive4org_/details_/gasol9emo tor#jjslauri* ,transcrib]'s note3 ,text enclos$ by und]scores is 9 italics 7italics74 ,text 9 small capital lett]s has be5 *ang$ to upp] case4 ,,! ,,gasol9e ,,motor by ,,h>old ,,:it+ ,,slauson1 ,m4 ,e4 ,au?or ( ,! ,motor ,boat ,out+ ,h&books ,new ,york ,out+ ,publi%+ ,company ,,mcmxiii ,copyright1 #aiac1 by ,out+ ,publi%+ ,company ,all rights res]v$ ,,cont5ts ,i4 ,,types ,,( ,,motors #i ,,ii4 ,,valves #bd ,,iii4 ,,be>+s #dc ,,iv4 ,,! ,,ignition ,,sy/em #fb ,v4 ,,magnetos #hc ,,vi4 ,,c>buretors ,,& ,,_! ,,fuel #ij ,,vii4 ,,lubrication #aab ,,viii4 ,,cool+ #acj ,,ix4 ,,two ,,cycle ,,motors #adh ,,! ,,gasol9e ,,motor ,,! ,,gasol9e ,,motor ,,*apt] ,i ,,types ,,( ,,motors ,!re are c]ta9 ev5ts t mu/ happ5 9 a gasol9e motor be=e ! eng9e w run ( its own accord4 ,= in/ance1 to obta9 successive p[] impulses1 ! *>ge mu/ fir/ be admitt$ to ! cyl9d] & compress$2 x mu/ !n be ignit$ to =m ! explosion t creates ! =ce at ! fly:eel2 & ! burn$ gases result+ f ?is explosion mu/ be eject$ 9 ord] to cle> ! cyl9d] = ! new *>ge4 ,to accompli% ?is s]ies ( ev5ts1 "s motors require f\r /rokes1 :ile o!rs d ! bus9ess 9 two4 ,^! are popul>ly call$ f\r-cycle & two-cycle motors1 respectively4 ,a cycle1 ( c\rse1 c be any r\nd ( ev5ts1 su* z a cycle ( ye>s--at ! end ( :i* "t ! previ\s happ5+s are s*$ul$ to repeat !mselves4 ,b 9 gas eng9e p>lance a cycle is tak5 to mean ! r\nd ( ev5ts f1 say1 ! explosion ( "o *>ge to ! ignition ( ! next4 ,?us1 x w be se5 t ! f\r-cycle motor requires f\r /rokes ( ! pi/on to accompli% its r\nd ( ev5ts1 & is1 prop]ly1 a f\r-/roke cycle motor4 ,likewise1 ! s-call$ two-cycle motor requires two /rokes to complete its cycle & %\ld !re=e be t]m$ a two-/roke cycle motor4 ,if ?is long] t]m9ology c\ld be adh]$ to1 !re w\ld be less misund]/&+ ( ! mean+s ( two- & f\r-cycle1 = :5 tak5 lit]ally1 ^! abbreviat$ =ms signify absolutely no?+4 ,usage seems to h made !m acceptable1 h[ev]1 & if ! read] w b rememb] t f\r-cycle1 = in/ance1 means f\r /rokes p] cycle1 ! t]m becomes almo/ z simple z does f\r-cyl9d]4 ,x is evid5t t !re are two /rokes = ea* revolution ( ! fly:eel--"o :5 ! crank is =c$ d[n & ! o!r :5 ! crank moves up4 ,z ! pi/on is atta*$ to ! crank ?r\gh ! m$ium ( ! connect+ rod1 ! /rokes are measur$ by ! motion ( ! pi/on4 ,?us1 s9ce x requires f\r /rokes ( ! pi/on to complete ! r\nd ( ev5ts 9 ! f\r-cycle motor1 ! explosions occur only at e second revolution ( ! fly:eel4 ,9 ?is connection x mu/ be rememb]$ t we are deal+ ) b "o cyl9d] at a "t1 = a f\r-cycle eng9e is practically a collection ( f\r s+le-cyl9d] units4 ,b ev5 ?\gh ! explosion 9 a f\r-cycle motor occurs only e o!r revolution1 ! eng9e is by no means idle dur+ ! int]val betwe5 ^! p[] impulses1 = ea* /roke has its own "w to d4 ,! explosion ex]ts a =ce simil> to a hamm] bl[ ( sev]al tons on ! pi/on1 & ! latt] is pu%$ d[n1 ?us =m+ ! fir/ /roke ( ! cycle4 ,! mom5tum ( ! fly:eel c>ries ! pi/on back aga9 to ! top ( its travel1 & dur+ ?is second /roke all ( ! burn$1 or exhau/1 gases are =c$ out & ! cyl9d] is clean$1 or scav5g$4 ,! pi/on is !n c>ri$ d[n on its ?ird /roke1 :i* t5ds to create a p>tial vacuum & sucks 9 ! *>ge = ! next explosion4 ,on ! f\r?1 & f9al1 /roke ( ! cycle ! pi/on1 /ill actuat$ by ! mom5tum ( ! fly:eel1 is pu%$ up aga9/ ! rec5tly-admitt$ *>ge & compresses ?is to a po9t five or six times great] ?an t ( ! atmosph]e4 ,at ! extreme top ( ?is la/ /roke1 ! sp>k is =m$1 caus+ ! next explosion1 & ! ev5ts ( ?is cycle are repeat$4 ,n[1 inasmu* z on "o up-/roke ( ! pi/on ! *>ge mu/ be held tightly 9 place 9 ord] t x may be compress$1 & on ! next up-/roke a free passage mu/ be (f]$ s t ! exhau/ gases may be =c$ out1 x is evid5t t a valve mu/ be us$ z a s5try plac$ at ! op5+s to re/ra9 ! desirable gas f escap+ & also to facilitate ! retreat ( ! objectionable exhau/4 ,likewise1 ! =ce ( ! explosion mu/ be conf9$ to ! pi/on on "o d[n-/roke 9 ord] t all ( ! en]gy may be conc5trat$ at ! crank1 :ile on ! succe$+ d[n-/roke a free passage mu/ be af=d$ to ! *>ge s t x may be suck$ 9 ?r\gh ! c>buretor4 ,consequ5tly a second valve mu/ be us$ to control ! inlet passage on ! d[n-/rokes & prev5t ! escape ( ! =ce ( ! explosion ?r\gh an op5+ t 0 int5d$ z an entrance = ! fre% *>ge4 ,?us valves are a necessity on all motors 9 :i* successive simil> /rokes ( ! pi/on d n p]=m ! same op]ations4 ,z quadrup$s & bip$s =m ! two great divisions ( ! animal k+dom1 s is ! motor sep>at$ into ! two ma9 classes ( f\r-cycle & two-cycle eng9es4 ,ev5 ?\gh to all ext]ior appe>ances1 ! two types ( motors may be id5tical1 ! di/9ction1 to ! eng9e]1 at lea/1 is z m>k$ z is ! diff]5ce betwe5 a /ork & an elephant4 ,! diff]5ce is some:at rev]s$1 h[ev]1 9 t1 :ile ! elephant has d\ble ! numb] ( legs ( ! /ork1 ! f\r-cycle motor has b "o-half ! numb] ( p[] impulses ( its two-cycle c\s9 at ! same spe$4 ,9 o!r words1 !re is an explosion 9 ea* cyl9d] ( ! two-cycle motor ) e revolution ( ! fly:eel1--in/ead ( ) alt]nate revolutions1 z is ! case ) ! f\r-cycle type4 ,b ! numb] ( ev5ts necess>y to produce ea* explosion mu/ be ! same 9 bo? types ( motors1 & consequ5tly x is only by d\bl+ up & p]=m+ sev]al op]ations ) ea* /roke t ! two-cycle motor c obta9 a p[] impulse ) ea* revolution ( ! fly:eel4 ,/>t+ ) ! ignition ( ! *>ge1 z 9 ! f\r-cycle motor1 let u see h[ ! ev5ts are comb9$ 9 ! two-cycle type s t all w occur )9 ! allott$ two /rokes4 ,directly aft] ! explosion !re is b "o ev5t t c happ5 if ?is =ce has be5 prop]ly h>ness$1 & t is ! viol5t d[nw>d travel ( ! pi/on4 ,j be=e ! bottom ( ?is d[nw>d /roke is rea*$1 h[ev]1 an op5+ is uncov]$ ?r\gh :i* ! exhau/ gases c exp5d ! rema9d] ( _! en]gy--:i* by ?is "t has become greatly r$uc$4 ,imm$iately aft] ?is ano!r passage is uncov]$ & ! *>ge is =c$ into ! cyl9d] "u pressure1 ?us help+ to cle> ! cyl9d] ( ! rema9d] ( ! exhau/ gases4 ,all ( ?is takes place ne> ! end ( ! d[n-/roke2 & at ! beg9n+ ( its return1 ! pi/on closes ! op5+s previ\sly uncov]$ = ! passage ( ! exhau/ gases & incom+ *>ge1 & !n compresses ! mixture dur+ ! rema9d] ( its up-/roke4 ,?us ! suction /roke & ! scav5g+ /roke ( ! f\r-cycle motor are disp5s$ ) 9 ! two-cycle type & e d[nw>d ?ru/ ( ! pi/on is a p[] /roke4 ,! two-cycle motor has be5 us$ 9 sev]al notable in/ances ) great success on motor c>s1 b by f> ! l>g] majority ( automobile p[] plants are ( ! f\r-cycle type4 ,9 view ( ! wond]ful simplicity ( ! two-cycle motor1 its small numb] ( mov+ p>ts1 & its m frequ5t p[] impulses1 x may well be ask$3 ,:y is ?is n 9 m popul> use on ! motor c>8 ,! f\r-cycle motor has b "o p[] /roke out ( e f\r1 :ile only alt]nate /rokes ( ! two-cycle motor consume p[] )\t produc+ any4 ,?is w\ld seem to indicate t1 = equal sizes & weights1 ! two-cycle motor w\ld produce twice z mu* p[] z ! f\r-cycle type--& ?is is true !oretically4 ,b ! f\r-cycle motor devotes an entire /roke to =c+ out ! exhau/ gases1 or scav5g+1 & ano!r entire /roke to draw+ 9 a fre% *>ge1 & x is evid5t t ^! op]ations c be done mu* m effectively 9 ?is mann] ?an :5 comb9$ ) sev]al o!r ev5ts foll[+ ea* o!r 9 su* rapid succession z is ! case ) ! two-cycle motor4 ,9 ! two-cycle motor ! incom+ *>ge mu/ be dilut$ to a c]ta9 ext5t ) ! exhau/ gases :i* h n be5 entirely expell$1 & ! intake valve port is uncov]$ = s %ort a "t t unless !re has be5 v high compression 9 ! base1 ! cyl9d] _c be entirely fill$ ) ! explosive mixture at high spe$s4 ,?is is describ$ 9 great] detail 9 ! la/ *apt] ( ?is volume4 ,?us1 :ile admitt$ly simpl] 9 con/ruction & op]ation ?an ! f\r-cycle1 ! two-cycle motor 9 its ord9>y =ms does n obta9 q z high an effici5cy f ! fuel z does its m complicat$ c\s94 ,ea* type has its di/9ct use1 h[ev]1 & 9 _m in/ances 9 :i* l[ initial co/ & simplicity ( design are m desirable ?an are economy ( fuel & high effici5cy ( op]ation1 ! two-cycle motor /&s supreme4 ,! s5tries t /& gu>d ov] ! passages ?r\gh :i* ! gases make _! entrance & exit may appe> 9 a v>iety ( guises1 b !y det]m9e ! %ape ( ! cyl9d]s ( a motor & divide ! f\r-cycle eng9e into a numb] ( classes4 ,= in/ance1 if ! valves controll+ ! admission ( ! explosive mixture are plac$ on "o side ( ! cyl9d]s & ^? (ficiat+ ov] ! exit ( ! exhau/ gases are locat$ on ! opposite side1 ! motor is kn[n z ! ,t-head type because ( ! %ape ( its cyl9d]s4 ,all valves t are plac$ at ! side ( ! cyl9d] mu/ op]ate 9 pockets s z n to int]f]e ) ! movem5t ( ! pi/on4 ,^! pockets are ca/ ) ! cyl9d] & =m a projection at its side ne> ! top4 ,:5 ^! projections are ca/ on opposite sides1 a cyl9d] hav+ ! %ape ( ! lett] ,t is =m$1 :ile if ! valves op]ate on ! same side1 ! s+le projection =ms a cyl9d] hav+ ! %ape ( ! inv]t$ lett] ,l4 ,h5ce cyl9d]s hav+ valves on opposite sides are call$ ,t-head motors1 :ile ,l-head motor is synonym\s = an eng9e hav+ valves on ! same side4 ,:5 ! valves are plac$ 9 ! head1 !re is no ne$ ( sep>ate pockets1 = ^! valves op]ate f above & d n int]f]e ) ! movem5t ( ! pi/on4 ,!re may be a comb9ation ( ^! positions1 "o set ( valves be+ plac$ 9 ! head & ! o!rs at ! side4 ,?is is kn[n z ! inlet 9 head1 exhau/ at side type--or vice v]sa1 z ! case may be4 ,! valve t has be5 9 almo/ univ]sal use 9 motor c>s is kn[n z ! poppet type1 z di/+ui%$ f ! slid+ & rot>y /yles4 ,z evid5c$ by its "n1 ! poppet valve is pu%$ or lift$ f its seat1 & ?us ! full area ( ! op5+ to ! passage is made available almo/ imm$iately4 ,! poppet valve is lift$ by a cam1 ! %ape ( :i* det]m9es ! relative spe$ ( op]ation ( ! valve1 & is return$ to its seat by a /iff spr+4 ,! nature ( ! contact t ! valve makes ) its seat dep5ds ^u ! condition ( ! surfaces & is ! decid+ factor z to :e!r ! jo9t is completely air-tight or n4 ,:5 ! exhau/ valve is op5$1 its head is ?ru/ directly 9 ! pa? ( ! hot1 out-ru%+ gases2 ^! same gases also swirl ar\nd ! edge ( ! seat4 ,! excessive heat & ! p>ticles ( c>bon t are (t5 f\nd 9 ! exhau/ gases t5d to corrode & build a deposit on ! edges ( ! valve & its seat1 ?us ev5tually prev5t+ p]fect contact f tak+ place4 ,?is makes necess>y ! gr9d+ ( ! valves--an op]ation t is famili> to ! majority ( motor c> own]s & driv]s4 ,:ile ! poppet valve motor is /ill us$ on ! majority ( automobiles1 a new & radical type ( valve me*anism has be5 giv+ successful results4 ,?is is kn[n z ! slid+ sleeve type ( motor1 & :ile x has be5 us$ = sev]al seasons 9 ,europe1 #aiab saw its adoption = ! fir/ "t 9 ,am]ica4 ,! sleeve motor1 x mu/ be und]/ood1 is ( ! f\r-cycle type1 ! ev5ts occurr+ 9 ! same ord] z on any ord9>y automobile motor1 & ! only diff]5ce lies 9 ! nature ( ! valves t control ! op5+s ( ! exhau/ & inlet passages4 ,t ?is diff]5ce is great1 h[ev]1 w be realiz$ :5 x is und]/ood t ! valves consi/ ( two conc5tric %ells1 9 ! inn] "o ( :i* ! pi/on reciprocates4 ,9 o!r words1 two holl[ cyl9d]s l9e ! int]ior ( ! cyl9d] ca/+ & replace ! poppet valves & pockets ( ! m famili> type ( motor4 ,^! sleeves1 or %ells1 or holl[ cyl9d]s--or :atev] "n x is *os5 to give !m--slide up & d[n 9 ! same l9e ( action z t ( ! pi/on4 ,a port1 or slot1 is cut ne> ! top on opposite sides ( ea* ( ! %ells4 ,^! f\r ports are s arrang$ t "o set op5s directly opposite ! intake passage1 :ile ! o!r op5s by ! exhau/ manifold entrance4 ,:5 x is said t ^! ports op51 x is meant t simil> slots 9 ! two sleeves come opposite ea* o!r1 or regi/]1 s t an unob/ruct$ passage = ! gas is (f]$4 ,! port 9 "o sleeve may be opposite ! intake pipe entrance1 b if ! slot 9 ! o!r sleeve does n correspond ) ?is1 ! passage is effectively clos$4 ,?us x w be se5 t ! ports are op5$ & clos$ by ! movem5t ( ! sleeves 9 opposite directions4 ,= example1 j be=e ! op5+ ( ! intake port1 ! inn] sleeves w be travel+ upw>d :ile ! out] %ell moves d[nw>d1 & ! slots 9 ! two %ells w be opposite ea* o!r at ! in/ant t !y pass ! inlet pipe4 ,?is gives a mu* quick] op5+ ?an w\ld be ! case if "o %ell /ood /ill :ile ! o!r mov$ d[nw>d1 & x is because ! slots approa* ea* o!r f opposite directions t ?is motor c be run effici5tly at high spe$s4 ,inasmu* z ?is is a f\r-cycle motor & ! explosions occur 9 ea* cyl9d] b once dur+ e two revolutions ( ! fly:eel1 ea* sleeve makes b "o /roke = e two ( ! pi/on4 ,! sleeves are op]at$ by ecc5trics atta*$ to a %aft driv5 at a two-to-"o spe$ by ! crank %aft ( ! motor1 & z !y are well lubricat$ !re is b v little friction g5]at$ betwe5 !m & ! pi/on4 ,9 fact1 x has be5 %[n t ! p[] requir$ to op]ate ! sleeves1 :5 well lubricat$1 is consid]ably less ?an t consum$ by ! spr+s & valve me*anism ( ! poppet valve motor1 = ! reason t ! =m] type ( valve does n op5 aga9/ ! pressure ( ! exhau/1 z is ! case ) ! ord9>y gas eng9e valve4 ,besides ! two- & f\r-cycle divisions1 a motor is kn[n by ! arrangem5t ( its cyl9d]s & is classifi$ z cyl9d]s ca/ sep>ately1 ca/ 9 pairs1 or triple ca/1 accord+ to :e!r !re are "o1 two or ?ree cyl9d]s to a unit4 ,! la/-nam$ type is n z common z are ! pair-ca/ cyl9d]s & ( c\rse c only be us$ on six-cyl9d] motors4 ,:5 all ( ! cyl9d]s ( a motor are ca/ 9 "o piece1 ! eng9e is kn[n z a bloc motor4 ,?is is a type t has come into popul> use = small & m$ium-siz$ p[] plants dur+ ! pa/ few ye>s on acc\nt ( ! simplicity ( its con/ruction & ! smoo? & compact design t is r5d]$ possible4 ,( c\rse x may be argu$ t1 ) su* a design1 ! entire set mu/ be replac$ if a s+le cyl9d] is damag$1 b ca/+s h be5 s improv$ t an accid5t or imp]fection requir+ ! r5ewal ( a cyl9d] is v r>e4 ,x is evid5t t1 beyond a c]ta9 size ( cyl9d]1 a bloc ca/+ becomes too bulky to be h&l$ conv5i5tly1 & z ! entire ca/+ mu/ be remov$ :5 x is desir$ to rea* ! connect+ rods1 crank %aft1 or pi/on r+s1 a motor s design$ w seldom be f\nd t develops m ?an =ty or fifty horsep[]4 ,?is type ( ca/+ is f\nd on "s six-cyl9d] c>s1 h[ev]1 b x is naturally only ! light sixes t w use su* a motor4 ,above six-cyl9d]s1 a motor is usually arrang$ ) its p[] units set at an angle on ei!r side ( ! v]tical1 ?us =m+ ! ,v-%ap$ motor4 ,sev]al eight-cyl9d] motors are s con/ruct$1 ! units be+ arrang$ f\r on a side & ea* set plac$ at an angle ( ab\t ?irty degrees f ! v]tical4 ,?is gives ! effect ( two f\r-cyl9d] motors plac$ side by side & op]at+ on ! same crank %aft4 ,9 ord] to make ! motor z compact z possible1 ! cyl9d]s are /agg]$2 or1 9 o!r words1 ! cyl9d]s ( "o set are plac$ opposite ! spaces betwe5 ! units ( ! o!r4 ,x w be se5 t ! ,v-%ap$ design ( motor %ort5s ! p[] plant & enables x to be set 9 a mu* small] space "u ! bonnet ?an w\ld be ! case 7 ! cyl9d]s plac$ "o 9 front ( ! o!r1 z 9 ! f\r- & six-cyl9d] types4 ,z a rule1 ! two-cyl9d]1 f\r-cycle motor is ( a diff]5t type f its f\r- & six-cyl9d] c\s9s1 & is kn[n z a horizontal oppos$ eng9e4 ,9 su* a motor1 ! cyl9d]s are set l5g?wise & ! pi/ons op]ate opposite ea* o!r 9 su* a mann] t a long1 n>r[1 & ?9 p[] plant is obta9$ t is especially well-suit$ = a location "u ! body ( ! c>4 ,9 fact1 ?is horizontal motor1 :i* may1 ( c\rse1 be ( ! f\r-cyl9d] type1 is ! only %ape t c well be us$ "u ! body or seat ( a t\r+ c>4 ,9 "s small runab\ts1 h[ev]1 ! d\ble-oppos$ motor is us$ to good advantage "u ! =w>d bonnet1 z 9 ! big fell[s4 ,!re are1 ( c\rse1 _m o!r features ( design t s]ve to diff]5tiate "o automobile p[] plant f ano!r1 b ^! are details t d n s]ve to classify ! motor1 & ! man :o kn[s :e!r 8 ma*9e is two- or f\r-cycle2 poppet or sleeve valve2 sep>ate1 pair1 or en bloc cyl9d] ca/+s2 & ,t- or ,l-head %ape w h at 8 f+]s' ends di/9ctions t w\ld h floor$ ! salesman ( a few ye>s ago4 ,,*apt] ,,ii ,,valves ,x has be5 /at$ 9 ! prec$+ *apt] t ! valves ( ! gasol9e motor are ! s5t9els plac$ on gu>d at ! entrance to & exit f ea* cyl9d] to make c]ta9 t ! mixture foll[s its prop] c\rse at ! prop] "t4 ,!re=e1 if we accept ! def9ition t a valve is a me*anical appliance = controll+ ! fl[ ( a liquid or a gas1 /rictly speak+ no su* ?+ z a valveless motor exi/s4 ,two-cycle motors are sometimes said to be valveless because ( ! fact t ! movem5t ( ! pi/on automatically regulates ! fl[ ( ! exhau/ & intake gases1 b 9 ?is case ! pi/on is 9 reality ! valve4 ,on ! f\r-cycle motor1 h[ev]1 l ev5ts take place only on alt]nate /rokes 9 ! same direction1 & consequ5tly "s controll+ me*anism t op]ates b once = e f\r /rokes ( ! pi/on is ne$$ to "t ! fl[ ( ! gases4 ,z has be5 /at$ 9 ! previ\s *apt]1 ! mo/ common =m ( valve is kn[n z ! poppet type f ! fact t its action is a lift+ "o4 ,su* a valve may be locat$ 9 a projection ca/ on ei!r side ( ! top ( ea* cyl9d]1 or x may be inv]t$ f ?is position & plac$ 9 ! cyl9d] head4 ,:5 9 ! =m] location1 ! valve is op5$ by an upw>d pu% on ! rod to :i* x is atta*$ at its c5t]1 :ile a valve plac$ 9 ! cyl9d] head is =c$ d[n to all[ ! escape or entrance ( ! exhau/ or intake gases4 ,! ord9>y type ( poppet valve is some:at simil> 9 %ape to a mu%room1 hav+ a v ?9 & flat head & a sl5d] /em4 ,! disc portion ( ! valve is kn[n z its head1 :ile ! rod =g$ ) ! valve & by :i* ! head is rais$ & l[]$ is call$ ! /em4 ,! projections ca/ 9 ! cyl9d]s ( a ,t-head or ,l-head motor1 & 9 :i* ! valves are plac$1 are kn[n z ! valve pockets4 ,valves s locat$ are lift$ by a direct upw>d pu% caus$ by ! rotation ( a cam & are return$ to _! clos$ position by means ( ! ext5sion ( a /iff spiral spr+ surr\nd+ ea* valve /em4 ,x is only ! out] edge ( ! l[] side ( ! valve head t comes 9 contact ) ! surr\nd+ surfaces ( ! op5+ :i* is clos$ :5 ! valve is return$ to its ord9>y position by ! spr+4 ,?is surface ( contact surr\nd+ ! op5+ is kn[n z ! valve seat1 & x is ?is1 toge!r ) ! edge ( ! valve :i* re/s aga9/ x1 t mu/ be gr\nd smoo? 9 ord] to insure a tight jo9t :5 ! valve is clos$4 ,on ! majority ( poppet valves ! edge ( ! head & ! seat aga9/ :i* x re/s are bevel$ to an angle ( approximately =ty degrees 9 ord] to con=m to ! natural direction tak5 by ! gases :5 !y are admitt$ or expell$4 ,9 a few cases1 h[ev]1 ! seat angle is n9ety degrees1 :i* means t ! edge ( ! head is gr\nd flat1 or /raight1 at "r angles to ! /em4 ,"o ( ! *ief advantages f\nd 9 ! use ( a poppet valve is ! fact t a l>ge op5+ c be obta9$ aft] ! valve head has be5 rais$ b a comp>atively %ort di/ance4 ,?is means t ! valve /em ne$ travel only a fraction ( an in* betwe5 ! full op5 & ! full clos$ position ( ! valve & t ! op]at+ me*anism = obta9+ ?is lift is simple4 ,practically e poppet valve1 !re=e1 is lift$ by means ( a cam1 :i* is a ?ick1 irregul>ly-%ap$ piece ( /eel m\nt$ on a %aft kn[n z ! cam %aft4 ,if ! end ( ! valve /em1 or a rod connect$ to x1 is held aga9/ ! p]iph]y ( ! cam :ile ! latt] is revolv$ by its %aft1 ! valve w be =c$ up1 or away1 r1 an am\nt correspond+ to ! increase 9 di/ance betwe5 ! p]iph]y ( ! cam at ?is po9t ( contact & its axis4 ,9 o!r words1 if ! cam 7 a true circle ) its axis pass+ ?r\gh its c5t]1 !re w\ld be no motion ( ! valve1 = all po9ts ( ! p]iph]y ( a circle are at ! same di/ance f ! c5t]4 ,consequ5tly a portion ( ! p]iph]y ( ! cam is ext5d$ 9 ! %ape ( a nose1 ! projection ( ?is beyond ! smalle/ diamet] ( ! cam be+ ! di/ance t ! valve w be lift$ :5 ?is po9t ( ! cam surface comes 9 contact ) ! /em or pu% rod4 ,! broad]1 or m blunt1 ! nose ( ! cam1 ! long] w ! valve rema9 op5 z ! cam %aft is revolv$1 :ile ! slope ( ! sides ( ! nose det]m9es ! rapidity ) :i* ! valve w be pu%$ out & back4 ,inasmu* z ! valve %\ld rema9 clos$ ?r\gh\t two-?irds or ?ree-qu>t]s ( e two revolutions ( ! fly:eel1 ! great] "p ( ! p]iph]y ( ! cam is circul>1 or at ! same di/ance f ! axis at all po9ts4 ,z has be5 m5tion$ be=e1 ! cam s]ves only to lift ! valve1 ! return ( ! latt] to its seat be+ obta9$ by ! =ce f a spr+ t is coil$ ar\nd ! /em4 ,?us ! spr+ holds ! end ( ! pu% rod at all times aga9/ ! p]iph]y ( ! cam4 ,?is pu% rod1 9 "s in/ances1 is a small b> ( special /eel t slides 9 guides ( long-we>+ be>+ alloy4 ,! upp] end ( ! pu% rod is 9 contact ) ! l[] end ( ! valve /em1 :ile its o!r extremity is (t5times design$ 9 ! =m ( a small /eel roll] t ?us s]ves to create a roll+ contact ) ! p]iph]y ( ! cam4 ,9 o!r designs1 ! l[] extremity ( ! pu% rod may be 9 ! =m ( a specially-h>d5$ /eel p9 ) a r\nd$ end1 :ile /ill a ?ird type consi/s ( a flat disc slightly (fset on ! end ( ! pu% rod s t v>i\s po9ts ( its surface w come 9 contact ) ! p]iph]y ( ! cam & ! we> w be ev5ly di/ribut$4 ,:atev] ! p>ticul> design1 h[ev]1 ! cam is well lubricat$ & bo? x & ! pu% rod are int5d$ to la/ z long z any "p ( ! motor4 ,_m motors are design$ ) "o valve at ! side & ! o!r1 usually ! intake1 9 ! head4 ,!re are also _m motors manufactur$ t h bo? ! intake & ! exhau/ valves locat$ 9 ! head1 9 :i* case ! valve pockets1 or projections1 are elim9at$4 ,su* valves may be op]at$ by ! same type ( cams & cam %aft z ^? us$ to op5 ! valves at ! side4 ,z ! op5+ ( a valve locat$ 9 ! head is d[nw>d1 h[ev]1 ! motion produc$ by ! cam on ! pu% rod mu/ be rev]s$ 9 direction4 ,?is rev]sal ( motion is obta9$ by means ( a lev] m\nt$ at its c5t] & plac$ 9 contact ) ! upp] extremity ( ! pu% rod at its out] end4 ,! o!r end ( ?is lev] op]ates 9 contact ) ! end ( ! valve /em1 & ?us an upw>d pu% on ! rod is conv]t$ into a d[nw>d ?ru/ on ! /em4 ,?is lev] t rev]ses ! direction ( ! pu% rod motion is kn[n z a rock] arm & is m\nt$ 9 a yoke ca/ ) ! cyl9d] head4 ,inasmu* z a spr+ is us$ to keep ! valve tightly clos$ :5 ! cam is n lift+ ! latt]1 x is ! contact ( ! valve head ) its seat t mu/ =m ! /op to ! motion ( ! spr+4 ,x w be se5 t ! =ce ( ! spr+ is communicat$ ?r\gh ! valve /em to ! pu% rod1 & !nce to ! p]iph]y ( ! cam :5 ! latt] is 9 a position to lift ! valve4 ,! pu% rod %\ld n be =c$ tightly aga9/ ! p]iph]y ( ! cam :5 ! valve is clos$1 h[ev]1 = ?is w\ld prev5t p]fect contact betwe5 ! valve & its seat4 ,consequ5tly !re %\ld be a c]ta9 am\nt ( play betwe5 ! end ( ! pu% rod & valve /em s t x w be c]ta9 t ! head is =c$ aga9/ ! seat ) ! full p[] ( ! spr+ & )\t ! cam s]v+ z a /op4 ,on ! o!r h&1 ?is play %\ld n be too great1 = ! cam & pu% rod w !n move an appreciable di/ance be=e ! valve is rais$4 ,?is w cause ! op5+ ( ! valve to occur late & w r$uce ! di/ance t ! /em is rais$1 ?us re/rict+ ! size ( ! op5+4 ,fur!rmore1 an undue am\nt ( play betwe5 ! ends ( ! pu% rod & /em w result 9 a p\nd or hamm] bl[ betwe5 ! two t is liable to we> ! surfaces rapidly4 ,! happy m$ium t w give ! be/ results may be obta9$ by prop]ly sett+ ! small valve tappets t are secur$ to ! end ( ! /ems or pu% rods4 ,by turn+ ! nut ( ! tappet 9 "o direction1 ! l5g? ( ! pu% rod w be r$uc$1 :ile ! rev]se op]ation w increase ! l5g? ( ! rod or /em4 ,?is is prim>ily int5d$ = tak+ up any we> t may occur at ! ends ( ! pu% rod or valve /em4 ,9 ! case ( eng9es hav+ ! valves 9 ! head1 ! long pu% rod ( ea* valve %\ld be s loose z to move p]ceptibly :5 %ov$ up & d[n by ! ?umb & f+]4 ,:5 ! rock] arm is press$ d[n aga9/ ! valve /em1 ! space betwe5 ! o!r end ( ! rock] arm & ! pu% rod %\ld be suffici5tly wide to admit a piece ( tissue pap]4 ,! same te/ may be made 9 connection ) valves locat$ at ! side1 aft] fir/ asc]ta9+ t ! end ( ! %ort pu% rod is re/+ firmly aga9/ ! p]iph]y ( ! cam4 ,! play w be app>5t1 ( c\rse1 only :5 ! valve is tightly clos$1 & 9 ord] to make c]ta9 t _! cams are 9 ! inactive position1 ! pi/on %\ld be set at ! beg9n+ ( ! explosion /roke :5 te/+ ! intake or exhau/ valve4 ,?is is at ! po9t ( ignition & is ! "t at :i* bo? valves %\ld be tightly clos$4 ,! cam %aft to :i* ! cams t op]ate ! valves are atta*$ is g5]ally plac$ inside ! crank case4 ,if ! motor is ( ! ,t-head type1 hav+ valves on opposite sides ( ! cyl9d]s1 ! cam %aft op]at+ ! exhau/ valves w be f\nd on "o side ( ! crank case1 :ile t = op5+ ! inlet valves w be locat$ on ! o!r4 ,if ! motor is ( ! ,l-head type1 all ! cams w be plac$ on ! "o %aft4 ,! cams are sometimes =g$ ) _! %aft 9 a solid piece1 :ile 9 o!r designs !y are key$ 9 place1 b :atev] type is us$1 ! cams & _! %aft may be consid]$ z integral ) ea* o!r4 ,! cam %afts are g5]ally driv5 by a ge> me%+ ) a small] "o atta*$ to ! front end ( ! crank %aft ( ! motor1 :i* =ms "o ( ! =w>d tra9 ( ge>s t are enclos$ 9 an alum9um case4 ,if ! cam %aft is driv5 at ! same spe$ z is ! crank %aft ( ! motor1 x w be se5 t ! valves w op5 once at e revolution ( ! fly:eel4 ,9 a f\r-cycle motor1 h[ev]1 ! explosion & o!r ev5ts occur b once 9 ea* cyl9d] = e two revolutions ( ! fly:eel1 & consequ5tly ! cam %aft mu/ be driv5 at "o-half ! spe$ ( ! crank %aft4 ,to obta9 ! prop] spe$ ratio1 ea* cam %aft is driv5 by a two-to-"o ge>1 :i* means t ! ge> on ! end ( ! crank %aft has b "o-half z _m tee? z h ^? atta*$ to ! cam %afts4 ,!re is ?us "o revolution ( ea* cam %aft ge> = e two ( ! crank %aft ge>1 & consequ5tly ea* cam %aft is driv5 at ! requir$ half spe$4 ,! cam %afts may be driv5 by a *a91 ! l9ks ( :i* fit ov] tee? cut on sprocket :eels1 b !re mu/ always be a con/ant relation betwe5 ! position ( ! cam %aft & t ( ! crank %aft4 ,?is con/ant relation is necess>y 9 ord] t ! valves w op5 & close at ! prop] po9ts dur+ ! travel ( ! pi/on4 ,= example1 ! exhau/ valve %\ld op5 t[>d ! end ( ! explosion /roke 9 ord] to all[ ! burn$ gases to be =c$ out1 & ! cam = op]at+ ?is valve %\ld always be 9 ! lift+ position at exactly ! prop] mom5t4 ,if ! cam %aft is n positively driv51 ?is position may *ange & ! exhau/ valve might be op5$ at ! beg9n+ ( ! ignition ( ! *>ge1 9 :i* case ! =ce ( ! explosion w\ld be wa/$ almo/ entirely4 ,on ! o!r h&1 ! inlet valve %\ld op5 at ab\t ! beg9n+ ( ! suction /roke 9 ord] t ! fre% *>ge may be drawn 9 by ! d[nw>d travel ( ! pi/on2 x is evid5t t ?is _c be op5$ at any o!r "t )\t a result+ loss 9 ! p[] develop$ by ! motor4 ,! prop] tim+ ( ! action ( ! valves is consequ5tly "o ( ! mo/ important adju/m5ts ( a motor4 ,:5 ! motor is assembl$ & te/$ at ! factory1 ! valves are prop]ly tim$ & !re is no possibility t !y w require fur!r adju/m5t 9 ?is respect until aft] ! eng9e is tak5 d[n = ! purpose ( clean+ or ! r5ewal ( a brok5 "p4 ,if x %\ld ev] become necess>y to remove "o ( ! cam %afts or any ( ! ge>s con/itut+ ! =w>d tra91 ! greate/ c>e %\ld be tak5 to make c]ta9 t all are return$ to exactly _! orig9al position4 ,a diff]5ce ( "o too? 9 ! relative me%+ ( ! ge>s may result 9 a loss ( fifty p] c5t4 ( ! p[] develop$ by ! motor4 ,absolute rules = ! prop] tim+ ( ! valves _c be giv5 "h1 = v>i\s motors are design$ ) slightly diff]5t positions at :i* ! exhau/ & inlet valves %\ld be op5$ & clos$4 ,a cam %aft %\ld nev] be remov$1 h[ev]1 )\t fir/ m>k+ ! int]me%+ tee? ( its driv+ ge> & ^? ( its companions4 ,?is may be/ be done by means ( a small prick pun* :i*1 :5 tapp$ lightly ) a hamm]1 w make a p]man5t m>k at ! desir$ po9t on ! surface ( ! ge>4 ,if ! motor is ( ! ,t-head type1 hav+ its valves op]at$ by two cam %afts1 c>e %\ld be tak5 to designate ! "r & left-h& ge>s s t _! positions w n be rev]s$ if bo? h be5 remov$ at ! same "t4 ,a safe me?od to pursue is to indicate ! "r-h& ge> ) "o pun* m>k1 :ile two %\ld be us$ = ! ge> at ! left4 ,?ree tee? %\ld be m>k$ on ea* pair ( int]me%+ ge>s4 ,t is1 a too? on "o ge> %\ld be m>k$1 & !n ea* ( ! tee? betwe5 :i* x me%es on ! o!r ge>4 ,! second cam %aft ge> %\ld be m>k$ be=e ! motor is turn$4 ,z has be5 /at$1 ! cams on _m motors are =g$ integral ) _! %afts1 & !re is consequ5tly no possibility ( ! removal ( "o f ! o!r4 ,^? cams :i* are key$ to _! %afts are accurately & rigidly set & ! keyways s cut t !re is slight *ance ( a mi/ake 9 return+ a cam t has be5 remov$4 ,x %\ld seldom be necess>y to remove a cam f its %aft1 h[ev]4 ,_m motors are provid$ ) tim+ m>ks on ! fly:eel to indicate ! positions ( ! latt] at :i* ! valves ( ! v>i\s cyl9d]s %\ld op5 & close4 ,9 connection ) ^! m>ks a po9t] atta*$ to ! crank case & indicat+ ! top ( ! fly:eel is us$4 ,:5 ! m>k$1 = example1 #d ,ex #j1 is "u ! po9t]1 x indicates t ! exhau/ valve on ! f\r? cyl9d] %\ld be ab\t to op54 ,if ! motor is turn$ b v little beyond ?is po9t1 a lift+ %\ld be felt at ! prop] pu% rod or valve /em4 ,x is well to te/ ! sett+ ( ! valves occasionally by means ( ^! m>ks1 = we> at ! rock] arms1 ! pu% rods1 ! valve /em1 or ! cam travel]s w result 9 unev5ly-tim$ valves4 ,x %\ld be rememb]$ t x is ! valve itself t %\ld op5 aft] ! prop] m>k on ! fly:eel has be5 pass$1 & t ! movem5t ( a long pu% rod is n suffici5t evid5ce t ! valve is beg9n+ to leave its seat4 ,!re may be s great an am\nt ( lo/ motion betwe5 ! pu% rod1 cam1 rock] arm1 & valve /em t ! fly:eel may be turn$ sev]al degrees beyond ! prop] po9t be=e ?is play w be tak5 up & ! valve itself w beg9 to move4 ,al?\gh ! tim+ ( a motor may be giv5 9 in*es ( pi/on travel beyond a c]ta9 dead c5t]1 at :i* po9t an exhau/ or inlet valve %\ld op5 or close1 x is g5]ally express$ 9 degrees ( fly:eel revolution4 ,suppose1 = example1 x is said t ! inlet valve %\ld op5 t5 degrees aft] ! beg9n+ ( ! suction /roke4 ,?is w\ld indicate t ! fly:eel %\ld be turn$ ?r\gh an arc ( t5 degrees f ! po9t at :i* ! pi/on is at its upp] dead c5t] be=e ! inlet valve = t p>ticul> cyl9d] %\ld beg9 to op54 ,express$ 9 t]ms ( fly:eel revolution1 ! total travel ( ! pi/on dur+ ea* /roke is #ahj degrees1 & z 9 ! proximity ( its dead c5t]s ! pi/on moves b a %ort di/ance 9 comp>ison ) ! size ( ! arc ?r\gh :i* ! fly:eel sw+s1 valves may be set v accurately by ?is me?od4 ,n all cam %afts = op]at+ ! valves are locat$ 9 ! crank case4 ,on sev]al designs ( motors ! cam %aft ext5ds along ! top ( ! cyl9d]s & is driv5 by a v]tical %aft & two sets ( bevel ge>s4 ,on su* motors bo? inlet & exhau/ valves are locat$ 9 ! cyl9d] heads1 & ow+ to ! proximity ( ! cam %aft1 b %ort pu% rods & valve /ems are ne$$4 ,! valves are sometimes op]at$ by means ( a bell crank or rock] arm t acts directly aga9/ ! cam surface & end ( ! valve /em4 ,on "s designs a d\ble cam is us$ :i* s]ves to op]ate bo? ! inlet & exhau/ valves ( ! cyl9d]4 ,! be>+s & cams ( su* a %aft are g5]ally enclos$ 9 oil & du/pro( cas+ screw$ to ! top ( ! cyl9d]s4 ,su* a cam %aft %\ld nev] be dism\nt$ )\t fir/ m>k+ int]me%+ tee? ( all spur & bevel ge>s t are conc]n$ 9 its op]ation4 ,all poppet valves mu/ be accessible & readily removable = ! purpose ( clean+ & gr9d+ ! contact surfaces ( ! head & seat4 ,! pockets 9 :i* ! valves plac$ at ! side ( a cyl9d] are locat$ are g5]ally provid$ ) l>ge screw plugs at ! top4 ,su* a plug may be remov$ ) a heavy wr5*1 & z ! op5+ :i* x fills is l>g] ?an ! head ( ! valve1 ! latt] may be remov$ aft] fir/ loos5+ ! spiral spr+ surr\nd+ its /em4 ,x is n necess>y to remove ! valve entirely f its pocket 9 ord] to gr9d its surfaces1 b ! p9 hold+ ! spr+ /op 9 place mu/ be )drawn s t ! t5sion ( ! spr+ on ! valve w n be s great z to prev5t ! latt] f be+ lift$ to p]mit ! introduction ( ! abrasive & turn+ ! head ) ! gr9d+ tool4 ,valves locat$ 9 ! head ( ! cyl9d] mu/ be remov$ entirely be=e _! surfaces c be gr\nd4 ,?is1 h[ev]1 is n a difficult op]ation1 z ! valve & its seat are g5]ally plac$ 9 a removable cage t ei!r screws 9 place or is held firmly 9 position by means ( a clamp or l device4 ,inasmu* z ! seat is conta9$ 9 ?is removable cage 9 :i* ! valve op]ates1 ! gr9d+ may be done at a "w b5* or on ! b$ ( any conv5i5t tool1 indep5d5tly ( ! location ( ! motor4 ,if a valve seems sluggi% 9 its action at high spe$s ( ! motor1 x is possible t its spr+ has become some:at weak5$4 ,^! spr+s are design$ to be exce$+ly /iff & heavy1 "s ( !m requir+ a pressure ( two hundr$ & fifty p\nds to compress ! coils "o in*4 ,) su* a spr+1 a special tool is requir$ to compress x suffici5tly to enable ! valve to be remov$4 ,a spiral spr+ t has become weak5$ may sometimes be /r5g!n$ by /ret*+1 b x is n to be suppos$ t ?is w\ld be ( great avail 9 ! case ( a spr+ z heavy z ^? us$ on "s valves4 ,if1 h[ev]1 a flat tool is introduc$ betwe5 ! v>i\s coils & ea* is sep>at$ slightly s t ! ultimate l5g? ( ! entire spr+ is great] ?an x 0 =m]ly1 x w ex]t a m p[]ful =ce on ! valve :5 x is return$ to its place surr\nd+ ! /em4 ,/iff5+ ! spr+1 h[ev]1 w be ( b little help if ! /em or pu% rod is tight 9 ! guides ?r\gh :i* x slides4 ,^! guides are (t5 made ( a special be>+ bronze & are design$ to )/& a l>ge am\nt ( we>1 b ! friction surfaces mu/ be lubricat$ if satisfactory s]vice is to be obta9$4 ,! l[] guide is g5]ally lubricat$ by ! oil f ! cams1 :ile ! guide ne> ! valve may receive its oil f ! eng9e cyl9d]4 ,x is n necess>y t ^! guides %all be pack$ or t !y %all be p>ticul>ly tight1 z !y are n call$ ^u to reta9 any gas or air pressure1 b !y mu/ hold ! /em & rod suffici5tly rigid to prev5t any p]ceptible side motion & ?us cause imp]fect seat+ ( ! valve4 ,9 replac+ valve /ems & pu% rods1 x %\ld be made c]ta9 t ea* works freely 9 its guide be=e ! spr+ is in/all$4 ,if !re is a slight t5d5cy = ! guide to grip ! rod or /em1 ! latt] %\ld be smoo!d ) em]y pap] at ! po9t at :i* x comes 9 contact ) ! guide & pl5ty ( oil appli$ until ! surfaces are well work$ d[n4 ,z ! di/ance t ! rods & /ems travel ?r\gh ! guides is comp>atively %ort1 ! we> is slight & only a small am\nt ( lubricant is ne$$1 provid$ ! rubb+ surfaces are smoo? & well-fitt$ to ea* o!r4 ,! me*anism ( a sleeve valve motor is slightly diff]5t f t ( ! poppet valve type4 ,ea* sleeve is op]at$ by a connect+ rod & ecc5tric m\nt$ on a %aft driv5 by a *a9 or ge>s f ! crank %aft ( ! motor4 ,! ecc5tric replaces ! cams ( ! poppet valve motor1 & z x mu/ ma9ta9 a c]ta9 relation ) ! position ( ! pi/on 9 ord] t ! op]ation ( ! valves %all be tim$ correctly1 ! same c>e mu/ be obs]v$ 9 replac+ ! ecc5tric %aft ) ! prop] tee? ( ! sprocket or ge> 9 me% z has already be5 describ$ 9 connection ) ! cam %aft ( ! poppet valve motor4 ,,*apt] ,,iii ,,be>+s ,9 ! g5]al mean+ ( ! t]m1 a be>+ is any "p t c>ries weight or pressure & at ! same "t rubs ov] ano!r surface4 ,accord+ to ?is def9ition1 ! portion ( ! cyl9d] walls trav]s$ by ! pi/ons are be>+s1 & t is 9 reality ! case1 b ! t]m has come to be appli$ m specifically to ! "p ( ! ma*9e 9 :i* ano!r "p revolves1 ei!r cont9u\sly or int]mitt5tly4 ,?us ! portions ( ! crank %aft on :i* x is support$ & ! p>ts ( metal 9 :i* !y revolve comb9e to =m ! crank %aft be>+s4 ,! %aft or /ud on :i* a ge> or :eel is m\nt$ & on :i* x revolves is ! be>+ ( t ge> or :eel4 ,al?\gh !y are conceal$1 z "s six-cyl9d] motors may be provid$ ) z _m z ?ree doz51 or m1 be>+s--if we consid] ^? on :i* ! cam1 pump1 & magneto %afts & ! ge>s are m\nt$--b :at descriptions1 rules1 & precautions apply to all hold true 9 ! l>ge/ s5se :5 ! crank %aft1 connect+ rod1 & wri/ p9 be>+s only are consid]$4 ,x is on ?is latt] class t ! greate/ we> ( ! motor is conc5trat$1 & ! own] :o und]/&s & inspects ^! ne$ fe> no tr\ble f ! cam %aft & ge> be>+s4 ,! exp]t w judge ( ! condition ( a motor by ! we> t has occurr$ 9 ! be>+s r ?an by any exhibition ( tempor>y p[] t x may develop 9 a %ort te/1 & x is = ?is reason t ! g5]al public runs a risk :5ev] x buys a second-h& c> t has n be5 ?or\ghly ov]haul$ by a reputable factory or inspect$ by a compet5t eng9e]4 ,! be>+s are 9 reality ! vitals ( ! motor1 & :5 ^! are worn beyond ! po9t ( easy adju/m5t or r5ewal1 ! repairs necess>y to place ! ma*9e 9 good condition w\ld (t5times co/ m ?an ! entire eng9e is wor?4 ,b ev5 9 a badly-worn motor1 ! be>+s may be tak5 up & doctor$ s t1 = a :ile at lea/1 ! eng9e w seem to run p]fectly & develop its full p[]4 ,?is w n be = long1 h[ev]1 & soon ! motor w beg9 to p\nd1 knock1 & rattle until an exam9ation w br+ to light ! true condition ( ! be>+s4 ,9 no ma*9e are ! be>+s subject$ to m sev]e usage ?an 9 ! automobile motor4 ,9 ord] t ! motor c> p[] plant %all be light 9 weight & occupy b a small am\nt ( space1 ! p[] mu/ be transmitt$ at high spe$s4 ,9 _m an automobile motor1 ! pressure imp>t$ to a s+le be>+ dur+ a c]ta9 portion ( its revolution may frequ5tly be well ov] two tons1 & 9 ?is same be>+1 ! spe$ ( rubb+ may approa* eight or n9e hundr$ feet p] m9ute4 ,9 o!r words1 at normal spe$s ( ! motor1 ab\t a six? ( a mile ( /eel surface w rub ov] a c]ta9 po9t 9 ea* crank %aft be>+ dur+ e m9ute t ! eng9e is runn+4 ,:5 prop]ly lubricat$1 an iron or /eel %aft w run 9 almo/ any k9d ( a metal be>+ t is suffici5tly /rong to c>ry ! weights & pressures impos$ ^u ! %aft4 ,! friction g5]at$ betwe5 two diff]5t metals t rub aga9/ ea* o!r1 h[ev]1 v>ies accord+ to ! composition ( ^? metals1 & consequ5tly x is advisable to employ "s mat]ial = a be>+ t w (f] a m9imum resi/ance to ! turn+ ( ! %aft4 ,friction mu/ be r$uc$ betwe5 all mov+ surfaces 9 ord] t ! me*anical effici5cy ( ! ma*9e %all be high1 & x is 9 ! be>+s t a l>ge am\nt ( p[] may be absorb$4 ,b ev5 betwe5 ! be/-lubricat$ surfaces1 employ+ ! mo/ effici5t metal z a be>+1 "s we> is b\nd to occur4 ,! crank %aft ( a f\r- or a six-cyl9d] motor is =g$ or saw$ f "o piece ( /eel1 & ) ! accurate ma*9+1 f9i%+1 & gr9d+ to :i* x is subject$1 x becomes an exp5sive "p ( ! eng9e4 ,consequ5tly x is advisable t ! we> ( be>+s ( su* p>ts %all be re/rict$ to ! boxes or surr\nd+ /ation>y metal 9 :i* ! %aft revolves at ^! po9ts4 ,9 ord] t all we> %all occur "h1 r ?an 9 ! %aft1 ! boxes are made ( or l9$ ) a s(t] metal4 ,if ! crank %aft is ( h>d /eel1 ! be>+ metal may be ( brass or bronze1 b x has be5 f\nd t babbitt metals give ! mo/ satisfactory s]vice = su* conditions--p>ticul>ly z a suffici5tly h>d crank %aft is difficult to produce comm]cially4 ,n only is a babbitt metal s(t] ?an ! /eel ( ! %aft & consequ5tly receives practically all ! we> ( ! be>+1 b x has ! add$ advantage ( melt+ at comp>atively l[ temp]atures4 ,at fir/ ?\ght1 ?is may seem l a d\btful advantage1 b 9 case ( a failure ( ! oil supply to t be>+1 ?is *>act]i/ic may be ! means ( sav+ ! crank %aft1 & possibly ! crank case1 cyl9d]s1 & connect+ rods1 f rack & ru94 ,! purpose ( lubrication is to r$uce friction betwe5 ! two surfaces 9 contact4 ,friction g5]ates heat1 & consequ5tly ! temp]ature ( a be>+ to :i* a suffici5t supply ( oil is n deliv]$ w be rais$ to a v high po9t4 ,?is high temp]ature w cause bo? p>ts ( ! be>+ to exp&1 ) ! result t ! fit becomes v tight & ! %aft b9ds or seizes 9 its box4 ,?is is ! famili> hot box1 s (t5 ! bane ( railroad m51 & if ! %aft is /ill run "u ^! conditions1 ! be>+ mat]ial w be torn out & ! surface ( ! %aft1 axle1 or :atev] ! revolv+ portion happ5s to be1 w be cut & abrad$1 (t5times beyond ! possibility ( repair4 ,x is su* accid5ts z ^! t are prev5t$ by ! use ( an easily-melt$ babbitt metal4 ,if ! oil supply becomes insuffici5t s t ! temp]ature ( ! be>+ is rais$ above a c]ta9 po9t1 ! babbitt metal w be melt$ & w run out ( its conta9] be=e any damage c be done to ! %aft4 ,effici5t runn+ _c1 ( c\rse1 be obta9$ ) ! be>+ burn$ out 9 ?is mann]1 b ! babbitt is quickly & easily r5ew$ & s]ves z a sort ( fusible safety valve t saves _m an exp5sive crank %aft replacem5t4 ,babbitt metals may be ( v>i\s compositions & proportions & _m conta9 lead1 b ^? :i* h be5 f\nd to give ! be/ results = use on ! crank %afts ( automobile motors are compos$ only ( t91 antimony1 & copp]4 ,if lead is us$ at all = ?is purpose1 x %\ld n appe> 9 proportions above "o p] c5t ( ! total composition4 ,inasmu* z a babbitt metal w fuse at a comp>atively l[ temp]ature & is mu* s(t] ?an /eel1 x is obvi\s t su* a mat]ial w n )/& heavy pressures unless re9=c$ & is unsuit$ = /ructural purposes4 ,consequ5tly ! babbitt is plac$ 9 ! be>+ box 9 ! =m ( a ?9 l9+ )9 :i* ! %aft revolves4 ,:5 ! %aft is l9$ up 9 ! box1 ! hot babbitt metal may be p\r$ 9 until ! space is entirely fill$4 ,:5 ! babbitt cools1 ! %aft may be turn$1 & :5 lubricant has be5 introduc$ 9 ! oil grooves :i* %\ld h be5 provid$ = ! purpose1 ! new be>+ w be ready = use4 ,x is n to be expect$ t ! majority ( motor c> own]s w rebabbitt ! crank %aft be>+s !mselves1 b x is necess>y to und]/& ! g5]al pr9ciples ( su* be>+ design 9 ord] to inspect ! motor intellig5tly & to det]m9e ^u ! repairs ne$$4 ,! above me?od ( r5ew+ burn$ out be>+s applies to babbitts 9 g5]al1 b ! sev]e usage t automobile eng9e crank %aft & connect+ rod be>+s are call$ ^u to )/& necessitates ! ex]cise ( a c]ta9 am\nt ( additional c>e4 ,x is necess>y t ! box %all fit ! %aft p]fectly1 s t !re c be no play1 & yet ! %aft mu/ be all[$ to turn easily )9 its surr\nd+ babbitt metal4 ,z 0 /at$ above1 ! %aft may be easily loos5$ f ! babbitt metal aft] ! latt] has cool$1 & ?is w\ld =m a satisfactory type ( be>+ 7 x n advisable t "s means be suppli$ by :i* ! we> c\ld be tak5 up )\t r5ew+ ! entire babbitt l9+4 ,! be>+ boxes ( ! crank %aft are ea* made 9 two halves1 ! l[] portion be+ ca/ integral ) ! crank case1 :ile ! upp] half is 9 ! =m ( a sep>ate cap t may be held 9 place by two or f\r bolts4 ,9 ?is case1 x is necess>y t ! boxes %all be 9 two sections1 = ! %ape ( ! crank %aft prev5ts x f be+ slid into place l5g?wise1 & consequ5tly x mu/ be plac$ on its be>+ f ! top4 ,9 "s designs ( motors ! be>+ caps =m ! l[] half ( ! box1 b z 9 ?is case ! base ( ! motor mu/ be inv]t$ 9 ord] to remove ! crank %aft1 ! caps w /ill be consid]$ z ! top halves ( ! boxes4 ,!re may be dove-tail grooves cut 9 ! inside ( ! halves ( ! boxes to reta9 ! babbitt metal aft] x has be5 p\r$ 9 place4 ,consequ5tly1 9 ord] to remove ! cap aft] r5ew+ ! babbitt l9+1 ! babbitt metal mu/ be cut 9 two at ! jo9t betwe5 ! two halves ( ! box4 ,! two halves ( ! box1 in/ead ( fitt+ closely toge!r1 are sep>at$ by ?9 /rips ( copp] or fib] kn[n z %ims t s]ve to relieve ! %aft f ! pressure ( ! bolts :5 ! be>+ cap is screw$ 9 place4 ,9 o!r words1 ! two halves ( ! box mu/ be held tightly 9 place by means ( ! bolts & nuts1 b none ( ?is pressure %\ld re/ on ! revolv+ %aft1 z ?is w\ld b9d x & prev5t x f turn+ easily4 ,consequ5tly by build+ up ! space betwe5 ! two halves ) ^! ?9 %ims ! prop] adju/m5t may be obta9$4 ,^! %ims provide ! me?od ( tak+ up ! we> 9 ! babbitt t w ev5tually result4 ,by loos5+ ! box reta9+ bolts & remov+ ! requir$ numb] ( %ims1 ! halves ( ! box w be br\ght clos] toge!r4 ,:5 ! be>+ cap is screw$ securely 9 place1 ! %aft %\ld be able to revolve freely )\t b9d+1 & yet ! fit %\ld be suffici5tly tight to prev5t any play at "r angles to ! l5g? ( ! %aft4 ,! pressure ( a %aft %\ld n be conc5trat$ 9 "o place1 b %\ld be di/ribut$ ov] z l>ge a surface ( ! babbitt metal z is possible4 ,a few ye>s ago1 :5 r5ew+ or repair+ a be>+1 x 0 consid]$ suffici5t to p\r 9 ! molt5 metal or to remove ! prop] numb] ( %ims--& ! be>+ 0 !n said to be ready = its "w4 ,b ev5 ?\gh no play 0 app>5t1 x 0 possible t ! %aft re/$ on only a few portions ( ! be>+ surface2 & ! increas$ att5tion t is n[ paid to ! details ( automobile con/ruction is no bett] exemplifi$ ?an 9 ! fact t ne>ly all be>+s are scrap$ 94 ,?is op]ation is simple & consi/s m]ely 9 remov+ any slight excess babbitt metal s t ! l9+ fits ! %aft ?r\gh\t its entire l5g? & circumf]5ce4 ,! babbitt is suffici5tly s(t to enable x to be peel$ or scrap$ ) a %>p tool provid$ = ! purpose1 & no great degree ( skill is necess>y 9 obta9+ ! requir$ fit4 ,9 ord] to det]m9e at exactly :at portions ( ! babbitt l9+ ! pressure is too great1 a dye or pa9t kn[n z blue+ is us$4 ,! be>+ portion ( ! crank %aft is pa9t$ ) ?is1 & ! cap is !n screw$ 9 place4 ,if ! crank %aft is !n turn$ & ! cap remov$1 x w be f\nd t ! blue+ has be5 transf]r$ f ! be>+ to ! portions ( ! babbitt metal on :i* ! pressure is ! greate/4 ,^! portions %\ld !n be %av$ ) ! tool m5tion$ above1 & ! same te/ repeat$4 ,z ! excess metal is remov$1 x w be f\nd t ! blue+ gradually is deposit$ ov] a l>g] area ( ! babbitt1 b x is n to be suppos$ t ! fit c be made s p]fect t ! color w be di/ribut$ ev5ly ov] ! entire surface4 ,c>e %\ld be tak5 to screw ! be>+ cap onto ! %ims z tightly z possible ea* "t ! blue+ te/ is to be made4 ,!re is no?+ t w heat a be>+ s quickly z a poor alignm5t ( ! %aft support$ by x4 ,= ?is reason gasol9e eng9e crank %afts are made exceptionally /rong & heavy1 especially ^? t are support$ only at _! extremities1 or at ^! po9ts & 9 ! c5t] ( _! l5g?4 ,a %aft t is b5t or twi/$ to ev5 ! slighte/ degree w soon burn out all ( its be>+s1 reg>dless ( ! am\nt ( oil t may be f$ to !m4 ,?is is because ( ! unequal pressures on ! diff]5t sides ( ! be>+ t all[ no room = ! admission ( ! film ( oil or o!r lubricant t is necess>y 9 all cases to prev5t a hot box4 ,on ! o!r h&1 ! be>+s mu/ all be 9 p]fect alignm5t1 = to set "o slightly (f w\ld produce ! same result z ?\gh ! %aft 7 b5t4 ,x w be se5 t ! use ( babbitt produces a self-align+ be>+1 = ! /raight %aft may be set 9 its prop] position & ! molt5 metal p\r$ ar\nd ! int]ior ( ! boxes4 ,z x is highly important t ! cap screws or nuts hold+ ! be>+ cap 9 place %\ld rema9 set z tightly z possible1 precautions mu/ be tak5 to prev5t any ( ^! f work+ loose4 ,?is may be done by means ( a cott] p9 t passes ?r\gh a hole 9 ea* bolt & ?r\gh a pair ( correspond+ not*es cut 9 ! top ( opposite faces ( ! nut4 ,a not* is g5]ally cut 9 ! top ( ea* face ( ! nut 9 ord] t ! latt] may be held securely 9 place 9 any position4 ,a cont9u\s wire pass+ ?r\gh all ( ! bolts & nuts is sometimes us$ in/ead ( ! individual cott] p9s4 ,_m mod]n automobile motors are design$ ) ! crank %aft runn+ 9 ball be>+s4 ,! type g5]ally us$ consi/s ( a r[ ( balls set betwe5 ! inn] & out] edges ( two conc5tric r+s4 ,! inside ( ! out] & ! outside ( ! inn] r+ are groov$1 con/itut+ ! ball race :i* =ms ! surface ^u :i* ! balls roll & :i*1 at ! same "t1 s]ves to hold !m 9 place4 ,ea* ball ( ! same be>+ mu/ be made ( exactly ! same size z its companions--or at lea/ )9 "o or two t5-?\s&?s ( an in*--& ea* "o mu/ be l>ge en\gh & ( suffici5t /r5g? to )/&1 by itself1 ! entire pressure 9 t be>+4 ,! inn] r+ slips ov] ! be>+ portion ( ! %aft ) a comp>atively tight fit1 :ile ! out] r+ rema9s /ation>y 9 its b$ 9 ! crank case4 ,! inn] r+ turns ) ! %aft1 ?us caus+ ! balls to roll 9 _! race4 ,ea* ball rolls ab\t its own axis1 & ! entire s]ies describes a circul> motion 9 ! same direction z t tak5 by ! %aft1 b consid]ably sl[]4 ,consequ5tly !re is no rubb+ 9 su* a be>+1 all ! motion be+ ( ! roll+ type1 & z ?is r$uces friction to a m9imum1 ! balls may be run )\t oil1 al?\gh lubrication ( ! prop] k9d w\ld c]ta9ly n h>m ! be>+4 ,ball be>+s are adapt$ only = a two-be>+ crank %aft1 = inasmu* z ! r+s mu/ be slipp$ ov] ! %aft1 x w\ld be manife/ly impossible to provide a ball be>+ 9 ! c5t]1 or 9 any o!r portion beyond a crank4 ,next 9 importance to ! ma9 be>+s ( a crank %aft are ^? by :i* ! connect+ rods communicate _! motion to ! cranks4 ,^! are kn[n z ! crank p9 be>+s or ! big end ( ! connect+ rod be>+s4 ,b inasmu* z ! upp]1 or small]1 end ( ! connect+ rods are t]m$ ! wri/-p9 be>+s1 ! o!r end may be call$ simply ! connect+ rod be>+4 ,! connect+ rod be>+s are simil> to ! ma9 be>+s describ$ 9 ! =ego+ pages & are r5ew$ & adju/$ 9 ! same mann]4 ,x is probable1 h[ev]1 t ^! receive a great] am\nt ( we> ?an d ! ma9 be>+s1 inasmu* z ! =m] obta9 ! direct impact ( ! =ce ( ea* explosion4 ,fur!rmore1 ! box ( ! connect+ rod be>+ describes a complete circle ) ea* revolution ( ! crank %aft1 9 addition to ! int]nal rotation ( ! crank1 :ile an alt]nate pu% & pull is deliv]$ to x by ! connect+ rod on its v>i\s /rokes4 ,consequ5tly x is ! connect+ rod be>+s t w become loose & require tak+ up be=e any att5tion ne$ be be/[$ on ! ma9 be>+s4 ,! we> w increase 9 ! connect+ rod be>+ z ! play becomes great]1 & if matt]s are n rem$i$1 ! box may ev5tually be brok51 ) ! result t ! end ( ! connect+ rod ?us fre$ w />t on ! rampage & w pun* sev]al pieces out ( ! bottom ( ! crank case4 ,brass or bronze be>+s may be us$ at ! big end ( ! connect+ rods1 b ! l>ge majority ( motor c> eng9es are provid$ ) babbitt$ be>+s at ^! po9ts4 ,x is especially necess>y t ^! be>+s %\ld be scrap$ to a p]fect fit & t ! %ims %\ld be adju/$ prop]ly s t no side play w be app>5t :5 ! connect+ rod is mov$ transv]sely to ! l5g? ( ! crank %aft4 ,:5 r5ew+ ! babbitts ( connect+ rod be>+s c>e %\ld be tak5 to all[ ! connect+ rod to sw+ free be=e ! molt5 metal is p\r$ 94 ,if ?is is n done1 ! connect+ rod may be =c$ slightly to "o side or ! o!r & w be held p]man5tly 9 ?is position :5 ! babbitt cools4 ,?is w induce a slight side ?ru/ 9 ! connect+ rod1 :i* w be communicat$ to ! pi/on1 ) ! result t ! side ( ! latt] & ( ! portion ( ! cyl9d] wall aga9/ :i* x moves w be scor$ & worn unduly4 ,inasmu* z ! connect+ rod be>+s are subject$ to su* a v>iety ( /ra9s1 & z loos5ess at ^! po9ts w result 9 s]i\s we>1 x is d\bly necess>y t ! nuts & bolts hold+ ! be>+ caps 9 place %\ld be securely wir$ or held tightly by means ( ! previ\sly-m5tion$ cott] p9s4 ,x is evid5t t ! base ( ! l>ge end ( ! connect+ rod =ms ! upp] half ( ! be>+ box1 :ile ! cap con/itutes ! l[] end & is atta*$ f ! bottom4 ,! connect+ rod be>+s on "s motors are h+$ at "o side s t ! cap may be turn$ away f ! crank %aft :5 x is desir$ to remove ! connect+ rod4 ,9 ?is case ! h+e replaces ! "o or two bolts or nuts on "o side ( ! box & is held 9 ! prop] position by ^? on ! o!r side4 ,:ile x may be easi] to adju/ a be>+ provid$ ) su* a cap1 ! results obta9$ c h>dly be expect$ to be z satisfactory = high-grade s]vice1 z is ! case :5 ! %ims may be us$ on bo? sides ( ! two halves ( ! be>+4 ,! wri/-p9 be>+ is locat$ at ! upp]1 or small1 end ( ea* connect+ rod1 &1 al?\gh x also c>ries ! full =ce ( ea* explosion1 x is n subject$ to z great we> z is ! be>+ at ! o!r end ( ! connect+ rod4 ,! reason = ?is is t ?is be>+ does n revolve & its friction surface is r$uc$ to ! comp>atively small arc ?r\gh :i* ! connect+ rod sw+s4 ,we> c occur "h1 h[ev]1 & because ?is be>+ is m inaccessible ?an is ! crank %aft or connect+ rod be>+1 tr\ble at ! wri/ p9 is (t5 ov]look$4 ,! wri/ p9 c only be rea*$ by ! removal ( ! pi/on & connect+ rod4 ,9 ! majority ( designs ! wri/ p9 is plac$ 9 ! sides ( ! pi/on & is held /ation>y by small keys or by set screws4 ,9 ?is case1 ! be>+ surface is =m$ by ! wri/ p9 & ! small end ( ! connect+ rod1 at :i* po9t ! greate/ we> occurs4 ,?is be>+ is nev] babbitt$1 b 9 ord] to r$uce ! we> on ! wri/ p9--:i* is g5]ally made ( h>d5$ /eel--! circul> op5+ 9 ! upp] end ( ! connect+ rod is l9$ ) a bronze or brass bu%+ t =ms a be>+ fit ov] ! wri/ p94 ,x is ?is l9+1 or bu%+1 t w we> r ?an ! h>d5$ /eel wri/ p91 b z ! =m] is easily remov$ & is n exp5sive to replace1 ! r5ewal ( ?is be>+ is a comp>atively simple matt]4 ,9 o!r types ( wri/ p9 be>+s1 ! p9 is held /ation>y 9 ! connect+ rod op5+ & turns ) x z ! connect+ rod sw+s ?r\gh its arc on ea* /roke ( ! pi/on4 ,) su* a design1 ! be>+ surface is =m$ by ea* end ( ! wri/ p9 & ! op5+s 9 ! sides ( ! pi/on walls 9 :i* ! wri/ p9 re/s4 ,9 ord] to =m an easily-replac$ be>+ surface1 ^! op5+s 9 ! pi/on walls are l9$ ) brass or bronze bu%+s t receive ! major "p ( ! we>1 z has be5 describ$ 9 connection ) ! bu%+s fitt$ to ! op5+ at ! small end ( ! connect+ rod4 ,!re is no?+ complicat$ or my/]i\s connect$ ) ! r5ewal or repair ( be>+s1 b ! man :o makes su* replacem5ts or adju/m5ts mu/ be an accurate & c>eful work]1 & :ile he ne$ n be a born ma*9i/1 he mu/ at lea/ possess ! knack ( h&l+ tools prop]ly4 ,& he mu/1 above all1 realize t ! design]s & manufactur]s ( 8 motor h be5 deal+ 9 measurem5ts ( ! ?\s&? "p ( an in* & t too great c>e _c be tak5 9 ! repair ( be>+s to obta9 a p]fect fit4 ,if he is r5ew+ a connect+ rod or a wri/ p9 be>+1 he mu/ also rememb] t ! pi/on has =m]ly be5 travel+ ov] a c]ta9 area ( cyl9d] surface t has n v>i$ 9 l5g? ! t5-?\s&? "p ( an in* betwe5 "o /roke & ! next4 ,consequ5tly1 ! babbitts or bu%+s %\ld be s replac$ t ! pi/on %all occupy ! same position relative to ! cyl9d] walls at ! top & bottom ( its /roke t x did =m]ly4 ,9 o!r words1 by v>y+ ! ?ickness ( ! top ( ! babbitt he is replac+1 he may *ange ! c5t] ( ! be>+ s t ! pi/on w />t on its upw>d /roke f a diff]5t po9t ?an 0 previ\sly ! case4 ,?us1 :ile ! l5g? ( travel ( ! pi/on w be ! same1 x w trav]se a slightly diff]5t portion ( ! cyl9d] walls "u ! new conditions1 & ?is w h ! effect ( *ang+ ! compression &1 possibly1 ( we>+ ! pi/on & r+s unduly4 ,,*apt] ,,iv ,,! ,,ignition ,,sy/em ,x 0 ! application ( ! electric curr5t to ! ignition sy/em ( ! gasol9e eng9e t fir/ enabl$ ^! new =ms ( p[] plants to be design$ ) suffici5t compactness & to possess en\gh flexibility to r5d] _! use practical on self-propell$ vehicles4 ,)\t ! electric ignition sy/em1 ! spe$ & p[] ( ! vehicle c\ld n well be controll$1 & ! explosions w\ld be unc]ta9 & irregul>1 at be/4 ,^? ( u :o are famili> ) ! electric gas light]s t 7 9 popul> use a few ye>s ago are furni%$ ) a conv9c+ demon/ration ( ! op]ation ( ! fir/ electric ignition sy/ems4 ,by pull+ a *a91 a wire1 or arm 0 rubb$ across a metal po9t until ! contact ?us =m$ 0 sudd5ly brok54 ,?is arm & ! /ation>y po9t =m$ ! two t]m9als ( an electric circuit1 :i* caus$ a fla% ( blue flame :5 ! contact 0 brok5 z ! "o 0 wip$ across ! o!r4 ,! flame ?us =m$ at ! in/ant ! contact 0 brok5 conta9$ suffici5t heat to ignite ! gas escap+ f ! burn] to :i* ! device 0 atta*$4 ,sp>ks w be =m$ 9 ! same mann] if we hold two wires1 connect$ to ! opposite poles ( a set ( batt]ies1 9 bo? h&s & wipe ! b>e ends across ea* o!r4 ,if an arrangem5t produc+ ?is effect is introduc$ into ! gas eng9e cyl9d] at ! portion 9 :i* ! *>ge is compress$1 ! fla% result+ :5 ! t]m9als are sep>at$ w s]ve to ignite ! explosive mixture4 ,! movable t]m9al is connect$ to a rod :i* passes ?r\gh ! cyl9d] walls & is atta*$ to a me*anism actuat$ by a cam revolv$ by ! eng9e4 ,?is me*anism is t]m$ ! make-&-break ignition sy/em = ! reason t contact ( ^! t]m9als is alt]nately made & brok5 to produce ! fla% ( electricity t explodes ! surr\nd+ *>ge4 ,9 ord] to produce a fla% ( suffici5t size :5 ! contact is brok51 ! nature ( ! curr5t1 obta9$ f ! dry cells or /orage batt]y is *ang$ some:at by conduct+ x ?r\gh a coil ( wire surr\nd+ a bundle ( b>e copp] wires4 ,?is is kn[n z a sp>k coil1 & :ile x is g5]ally us$ ) batt]y ignition ( ! make-&-break type1 magnetos may be design$ :i* produce ! prop] k9d ( curr5t direct1 )\t ! aid ( ! coil4 ,an ord9>y set ( six dry cells1 connect$ 9 s]ies--or l ) unlike poles--w produce a curr5t ( betwe5 tw5ty & tw5ty-five amp]es at a pressure ( ab\t n9e volts--assum+ ea* batt]y1 :5 new1 to deliv] tw5ty-five amp]es at a pressure ( "o & "o-half volts4 ,! s]ies wir+ gives ! entire set ! comb9$ voltage ( all ) ! av]age amp]age ( "o4 ,= ! b5efit ( ^? :o h =gott5 _! elem5t>y physics1 let x be rememb]$ t ! amp]e is ! measure ( curr5t am\nt1 or fl[1 :ile ! voltage is conc]n$ only ) ! pressure ( ! curr5t4 ,by ! use ( v>i\s arrangem5ts ( w9d+s ( wires1 ! voltage may be rais$ ) a correspond+ decrease 9 ! amp]age--& vice v]sa4 ,?us1 if a coil is us$ t d\bles ! orig9al numb] ( amp]es produc$ by ! batt]y1 ! voltage w be halv$4 ,! make-&-break type ( ignition has be5 us$ successfully = _m ye>s1 b ) ! p]fection ( ! magneto1 x has be5 l>gely supplant$1 9 automobile practice1 at lea/1 by ! jump sp>k1 or high-t5sion sy/em4 ,because ( ! fact t ! latt] sy/em is less exp5sive to con/ruct & is highly effici5t1 x w be f\nd also on ! majority ( ! old] c>s n equipp$ ) a magneto4 ,x 0 f\nd1 aft] ! g5]al adoption ( ! make-&-break ignition sy/em1 t a flame 0 n necess>y = ! combu/ion ( a prop]ly-mix$ *>ge 9 ! eng9e cyl9d]4 ,9 fact1 a t9y sp>k1 sc>cely "o-sixte5? ( an in* long & no l>g] ar\nd ?an a p91 0 discov]$ to be suffici5t to produce ! ignition ( ! *>ge4 ,al?\gh1 ( small volume1 su* a sp>k g5]ates int5se heat1 & x is ^u ?is quality1 r ?an ^u area1 t ! *>ge dep5ds = its ignition--al?\gh x is claim$ t a l>ge flame w produce m complete1 rapid1 & consequ5tly m effici5t1 combu/ion4 ,b ! jump sp>k possesses ! advantage ( requir+ no mov+ p>ts project+ ?r\gh ! cyl9d] walls into ! combu/ion *amb]1 & its great] simplicity ov] t ( ! make-&-break sy/em has result$ 9 its almo/ univ]sal adoption by automobile manufactur]s4 ,x has be5 /at$ 9 a prec$+ p>agraph t ! voltage produc$ by ! av]age batt]y set w n exce$ n9e or t51 & ev5 ! pressure g5]at$ by ! ord9>y magneto is n great] ?an ?is4 ,b air is n a good conductor ( electricity & =ms a v high resi/ance to ! passage ( a curr5t4 ,x is only :5 ! high resi/ance ( an air gap is enc\nt]$ 9 its circuit1 h[ev]1 t a sp>k w be =m$ by ! curr5t1 & consequ5tly ! =m ( electricity us$ 9 ?is sy/em mu/ h resi/ance-ov]com+ prop]ties4 ,b x is only by rais+ ! voltage ( ! curr5t t ev5 a %ort air gap c be bridg$ by ! sp>k4 ,9 fact1 a pressure ( some:at ov] fifty ?\s& volts is requir$ to produce a sp>k less ?an an in* long 9 ! air4 ,al?\gh only call$ ^u to jump a gap ab\t a sixte5? ( an in* across1 ! ord9>y high-t5sion curr5t is capable ( bridg+ a space eight or t5 times ?is wid? 9 ord] t ample pressure w always be assur$ = ! =mation ( ! sp>k4 ,fur!rmore1 ! w>m gases 9 :i* ! sp>k is =m$ 9 ! cyl9d] increase ! resi/ance ord9>ily enc\nt]$ & x is consequ5tly necess>y to raise ! voltage above ! am\nt t w\ld be ne$$ 7 ! plug expos$ to ! op5 air4 ,^! conditions make advisable a pressure ( f twelve ?\s& to ?irty ?\s& volts 9 ! ord9>y jump sp>k sy/em1 & x is f ?is voltage t ! t]m high t5sion is obta9$4 ,! n9e or t5 volts deliv]$ by ! batt]ies are trans=m$ to ?is l>g] am\nt by means ( an induction coil--or :at is m g5]ally t]m$ m]ely ! coil4 ,?is is 9 reality a /ep-up trans=m]1 s9ce x trans=ms ! curr5t f "o ( l[ voltage to ano!r ( two or ?ree ?\s& times its orig9al pressure4 ,?is trans=m] consi/s ( two coils ( wire1 "o surr\nd+ ! o!r4 ,! inn] coil is compos$ ( a comp>atively few numb] ( turns ( r co>se wire w\nd ar\nd a s(t iron core1 & is t]m$ ! prim>y w9d+1 s9ce ! curr5t f ! batt]ies is l$ directly ?r\gh x4 ,! out] coil is compos$ ( _m turns ( a v f9e wire1 all ( :i* are ?or\ghly insulat$ f ea* o!r & f ! inn] w9d+4 ,?is out] coil is t]m$ ! second>y w9d+ & is ! "o f :i* ! high-t5sion1 or trans=m$1 curr5t is tak54 ,?is second>y curr5t is induc$ f ! prim>y w9d+ ?r\gh :i* ! batt]y curr5t passes & possesses a voltage t has increas$ ov] its orig9al am\nt 9 ! same proportion t ! numb] ( turns 9 ! second>y w9d+ be>s to ^? 9 ! prim>y4 ,!re=e1 if ! orig9al batt]y voltage is t5 & !re are a ?\s& times z _m turns 9 ! second>y w9d+ z 9 ! prim>y1 ! result+ high-t5sion curr5t w h a pressure ( t5 ?\s& volts4 ,! pr9ciple ( ! coil is dep5d5t entirely ^u t peculi> electric prop]ty kn[n z induction4 ,ar\nd e wire ?r\gh :i* an electric curr5t passes are invisible l9es ( =ce simil> to ^? t emanate f an electro-magnet4 ,^! l9es ( =ce surr\nd ! wire ?r\gh\t its l5g?1 & arrange !mselves 9 a spiral =mation4 ,insulation has no effect on ^! l9es ( =ce1 & !y may be collect$ f wires :i* are sep>at$ f ea* o!r by sev]al ?icknesses ( curr5t-conf9+ mat]ial4 ,x is1 ( c\rse1 necess>y to use insulat$ wires 9 ! con/ruction ( ^! coils1 = o!rwise ! curr5t w\ld m]ely pass to adjo9+ turns & w\ld n travel ! entire l5g? ( ! w9d+--& !re=e z great a numb] ( l9es c\ld n be collect$4 ,if an additional lay] or lay]s ( wire is w\nd ar\nd ! fir/ s]ies ( turns1 ! l9es ( =ce w be collect$1 or induc$1 by ?is second coil1 & w con/itute ! second>y curr5t4 ,! induction effect is greatly increas$ if ! prim>y curr5t is all[$ to accumulate1 or pile up1 & dis*>ge1 alt]nately1 = ?is surg+ ( ! curr5t creates a sort ( ov]fl[ f ! orig9al conta9+ wires4 ,ohm's ,law1 :i* /ates t ! numb] ( amp]es 9 an electric circuit is equal to ! voltage divid$ by ! numb] ( ohms ( resi/ance enc\nt]$1 %[s t ! curr5t w be *ang$ by its passage ?r\gh ! prim>y w9d+4 ,! induc$ curr5t is fur!r *ang$1 & :5 collect$ by ! second>y w9d+ & s5t ?r\gh its long coils1 we h ! high-t5sion circuit m5tion$ 9 ! prec$+ p>agraph4 ,if ! read] rememb]s t x is b "o hundr$ & t5 volts t is us$ to op]ate our electric lights & t five hundr$ w run a trolley c>1 he may wond] :y x is n dang]\s to h&le z great a pressure z ! ?irty ?\s& volts t are us$ 9 connection ) ! ignition sy/em ( a motor c>4 ,b x is ! comb9ation ( great voltage ) high amp]age t is dang]\s1 & if x is rememb]$ t1 z ! =m] is increas$1 ! latt] is r$uc$ correspond+ly1 x w be realiz$ t ! ord9>y high-t5sion ignition curr5t possesses a quantity1 or fl[1 ( sc>cely "o "o-hundr$? ( an amp]e4 ,if we lik5 ! electric curr5t to a fl[ ( wat] 9 a pipe1 we h ! amp]es correspond+ to ! quantity ( ! fl[1 or ! numb] ( gallons t w be deliv]$ at ! outlet 9 a giv5 "t4 ,cont9u+ ?is analogy1 ! voltage ( ! electric curr5t w be ! pressure1 or head 9 ! wat] sy/em1 & ! curr5t f ! batt]ies be=e ! coil is rea*$ w correspond to a mod]ate fl[ ( wat] at a comp>atively l[ pressure4 ,aft] ! coil has trans=m$ ! curr5t to ! high voltage1 we h ! conditions ( a v small op5+ 9 ! wat] pipe conta9+ a trem5d\s pressure4 ,su* a /ream w possess b small fl[1 b its high pressure w enable x to be squirt$ to a f> great] di/ance ?an w\ld be ! case 7 its volume l>g] & its head less4 ,al?\gh ! pressure is high1 its quantity is s l[ t ! /ream c d b little damage & w\ld sc>cely m ?an tickle ! fle% ( a p]son aga9/ :om x is direct$4 ,?us x is ) ! ignition curr5t4 ,x c tickle1 r vici\sly1 sometimes1 z _m p]sons w av]1 b ! am\nt ( electricity involv$ is s slight z to r5d] ! high pressure h>mless4 ,nev]!less1 x is well to avoid all[+ ! f+]s or ! arm to become a "p ( ! high-t5sion circuit1 = ! result may be />tl+ z well z annoy+4 ,b 9 ord] t ! high voltage %all be induc$ 9 ! second>y coil1 ! prim>y circuit mu/ be alt]nately made & brok5 betwe5 "o /roke & ! next4 ,consequ5tly prop] pil+ up1 or surg+1 ( ! curr5t w be effect$4 ,?is is accompli%$ by means ( an int]rupt] t ei!r vibrates rapidly or snaps once at ! =mation ( ea* sp>k4 ,! =m] is ! m common type us$ ) batt]y ignition & is kn[n z a vibrat+ coil4 ,a circuit break] is g5]ally incorporat$ 9 ! me*anism ( a magneto1 & consequ5tly :5 su* an in/rum5t is us$1 ! vibrator on ! coil is disp5s$ )4 ,x is ! vibrator on ea* coil t =ms ! buzz t c be he>d :5ev] ! box cov] is remov$1 & t (t5 furni%es a simple te/ = det]m9+ ! condition ( ! ignition sy/em ( ! p>ticul> cyl9d] ) :i* t coil is connect$4 ,! vibrator is a flat1 spr+ /eel piece t re/s ne> "o end ( ! s(t iron core ar\nd :i* ! prim>y coil is w\nd4 ,! spr+y nature ( ! vibrator ord9>ily holds x aga9/ a small1 adju/able contact po9t t %\ld be set ab\t an eigh? ( an in* f ! end ( ! above-m5tion$ s(t iron core4 ,! prim>y coil is s wir$ t its curr5t passes ?r\gh ! vibrator /eel & ! contact po9t aga9/ :i* x re/s4 ,z soon z ! curr5t travels ?r\gh ! coil surr\nd+ ! s(t iron core1 h[ev]1 ! latt] becomes magnetiz$ & draws ! /eel vibrator t[>d x4 ,?is breaks ! circuit1 ! magnetism ( ! iron core disappe>s1 & ! vibrator returns to its orig9al position aga9/ its contact po9t4 ,b ?is action aga9 =ms ! circuit1 & ! same op]ation is repeat$ z long z ! curr5t is all[$ to fl[ t[>d ! coil4 ,?is is ! same pr9ciple on :i* an electric bell is rung1 b ! vibrator ( ! coil makes & breaks ! circuit mu* m rapidly on acc\nt ( ! less weight ( ! mov+ p>ts4 ,?is vibration ( ! coil int]rupt] is s rapid--hundr$s a second probably--t ! result+ sp>k is practically cont9u\s & %[s no effect ( ! breaks 9 ! circuit4 ,ev5 ?\gh x is ! prim>y curr5t1 ( l[ voltage1 t is int]rupt$ by ! vibrator1 ! frequ5cy ( ^! int]ruptions causes a slight sp>k+1 or arc+1 at ! contact po9ts4 ,^! are !re=e subject$ to r a high degree ( heat1 z well z a l>ge am\nt ( we>1 & x is necess>y t !y be made ( a mat]ial t w resi/ bo?4 ,plat9um has be5 f\nd to be unusually suitable = ?is purpose1 b ow+ to its high co/1 only a small am\nt 9 ! =m ( two po9ts1 or buttons1 is us$4 ,"o ( ^! po9ts is plac$ 9 ! vibrator /eel1 & ! o!r is emb$d$ 9 ! end ( ! screw aga9/ :i* ! fir/ re/s4 ,?us ! actual contact is made aga9/ ^! heat-&-we>-resi/+ plat9um po9ts1 & x is evid5t t ^u _! prop] action dep5ds ! =mation ( ! sp>k 9 ! cyl9d] ) :i* t p>ticul> vibrator is connect$4 ,not)/&+ ! fact t plat9um possesses high heat-resi/+ prop]ties1 ! con/ant arc+ at ! contact po9ts w ev5tually =m a sort ( corrosion 9 :i* m9ute p>ticles ( ! mat]ial are c>ri$ f "o po9t to ! o!r 9 ! direction 9 :i* ! curr5t fl[s4 ,if ! curr5t is rev]s$1 ! corrosion w take place 9 ! o!r direction1 & consequ5tly ! plat9um po9t t =m]ly lo/ a "p ( its mat]ial w gradually be built up aga94 ,?is corrosive action is kn[n z pitt+1 & :ile x may be r$uc$ to a c]ta9 ext5t by rev]s+ ! t]m9als ( ! batt]y1 z describ$1 ! plat9um w occasionally require additional att5tion4 ,a coil hav+ badly pitt$ contact po9ts on ! vibrator w /ick & w cease to =m a sp>k regul>ly4 ,x is (t5 difficult to di/+ui% betwe5 tr\ble aris+ f badly-pitt$ contact po9ts & t caus$ by weak or ne>ly-exhau/$ batt]ies1 z ei!r ailm5t produces ! same symptoms ( irregul> runn+ & j]k+ 9 ! motor4 ,= ?is reason1 a volt & amp]e met] = measur+ ! pressure & am\nt ( ! curr5t deliv]$ by ! batt]ies %\ld =m a "p ( e automobile own]'s tool equipm5t4 ,x is ! amp]age1 r ?an ! voltage1 t is r$uc$ ?r\gh cont9u$ use ( ! batt]ies1 & :5 ?is quantity falls bel[ n9e or t51 ! cells %\ld be disc>d$--or re*>g$1 9 ! case ( a /orage batt]y4 ,b if ! ignition occurs irregul>ly :5 ! batt]ies are deliv]+ ! prop] am\nt ( curr5t1 x is probable t ! tr\ble lies 9 ! pitt$ condition ( ! plat9um contact po9ts ( ! vibrator ( ! coil4 ,f9e em]y clo? rubb$ ov] ! surfaces ( contact %\ld s]ve to rem$y matt]s4 ,x %\ld be made c]ta9 t ! result+ surfaces on ! plat9um po9ts are n only rubb$ smoo?1 b level1 z well1 9 ord] t ! entire area ( ea* w re/ 9 contact & ! curr5t w n be conc5trat$ at a small portion4 ,x is probable t !re w be a screw adju/m5t on ! vibrator by means ( :i* ! =ce ) :i* ! latt] re/s aga9/ its contact po9t may be regulat$4 ,if ! vibrator is set too tight1 an undue am\nt ( curr5t w be requir$ to magnetize ! core ( ! coil suffici5tly to pull ! vibrator away f its contact po9t1 & ! batt]ies w soon run out4 ,on ! o!r h&1 ! t5sion ( ! vibrator %\ld be suffici5t to enable x to spr+ away f ! core ( ! coil z soon z ! circuit is brok51 = o!rwise ! vibrator w lag & w n be z lively z is necess>y to obta9 ! be/ results4 ,! contact screw %\ld be set s t ! vibrator re/s ab\t ?ree-?irty-seconds ( an in* f ! end ( ! magnetic core4 ,aft] ! t5sion ( ! vibrator has be5 set to approximately ! prop] am\nt1 ! e> mu/ be tru/$ = ! correct adju/m5t ( ! contact screw4 ,:5 ! swit* is ?r[n on & ! motor turn$ until curr5t fl[s ?r\gh ! coil1 ! result+ buzz emanat+ f ! vibrator %\ld be decid$ & =ceful4 ,if ?is buzz is exce$+ly high-pit*$1 x is an indication t ! vibrator has be5 set too tight1 & its t5sion %\ld be loos5$ if unscrew+ ! contact po9t slightly does n l[] ! tone4 ,x mu/ be rememb]$ t ! t5sion ( ! vibrator c be *ang$ by turn+ ! contact screw4 ,if ?is screw is turn$ d[n s t x =ces ! vibrator t[>d ! iron core1 ! t5sion w be great] ?an w be ! case if ! contact po9t is turn$ to ! left4 ,if ! buzz ( ! vibrator is pit*$ l[] ?an 0 =m]ly ! case1 x is an indication t ! contact po9t %\ld be screw$ d[n1 or t ! t5sion ( ! vibrator %\ld be tight5$4 ,x is probable t turn+ ! contact screw to ! "r w produce ! prop] result4 ,:ile ^! *anges 9 ! position ( ! contact screw are be+ made1 ! swit* %\ld be left turn$ on s t ! v>iations 9 ! pit* ( ! vibrator buzz may be detect$4 ,:5 an ev5ly-pit*$1 vigor\s buzz has be5 secur$1 ! swit* %\ld be ?r[n on & (f sev]al times to make c]ta9 t ! response ( ! vibrator is in/ant & positive4 ,! swit* %\ld !n be left on & ! vibrator all[$ to buzz = sev]al seconds 9 ord] t x may be det]m9$ :e!r ! pit* ( ! s\nd w *ange1 or n4 ,if !re is a *ange noticeable1 ! contact screw %\ld be readju/$ until ! pit* ( ! buzz rema9s con/ant z long z ! circuit is clos$4 ,! coil & batt]ies or magneto by no means =m ! entire ignition sy/em1 al?\gh ! g5]ation ( ! sp>k dep5ds entirely ^u !m4 ,! sp>k mu/ be regulat$ to occur at ! prop] po9t 9 ! /roke ( ! pi/on1 z a cont9u\s sp>k w\ld n only wa/e ! curr5t1 b w\ld cause ! ignition ( ! *>ge dur+ ! upw>d /roke & w\ld result 9 an impulse 9 ! rev]se direction t w\ld prev5t ! motor f runn+ = m ?an half a turn4 ,! device by :i* ! "t ( ! occurr5ce ( ! sp>k is regulat$ is call$ ! tim]4 ,?is consi/s1 9 its ess5tials1 ( a h>d rubb] disc provid$ ) a copp] or brass segm5t4 ,a metal p91 roll]1 or ball re/s aga9/ ! out] edge ( ! disc1 & z ! latt] is revolv$1 ! electrical circuit is complet$ :5ev] ! two metal portions come 9 contact ) ea* o!r4 ,! h>d rubb] be+ a non-conductor ( electricity1 prev5ts ! fl[ ( ! curr5t at all o!r times4 ,! disc ( ! tim]1 kn[n z ! commutator1 is s ge>$ t x revolves 9 unison ) ! motor4 ,inasmu* z ! explosion occurs 9 ea* cyl9d] only at e second /roke ( a f\r-cycle motor1 ! commutator on ?is type ( eng9e is ge>$ to revolve at "o-half ! spe$ ( ! crank %aft4 ,9 ! two-cycle motor1 on ! o!r h&1 ! explosion occurs 9 ea* cyl9d] at e revolution1 & consequ5tly ! commutator %\ld turn at crank %aft spe$4 ,al?\gh ! sp>k is int5d$ to occur approximately at ! extreme upp] end ( ! compression /roke1 a few degrees v>iation bo? above & bel[ ?is po9t is necess>y 9 ord] to obta9 ! desir$ spe$ & p[] flexibility ( ! gasol9e motor4 ,at high spe$s1 ! sp>k %\ld be tim$ to occur be=e ! pi/on rea*es ! extreme top ( its /roke1 :ile at sl[] revolutions ( ! motor ! ignition %\ld take place1 9 "s in/ances1 j aft] ! pi/on has />t$ to desc5d4 ,?is v>iation ,9 tim+ is obta9$ by sw++ ! contact piece ( ! tim]--kn[n z ! bru%--ei!r =w>d or backw>d ?r\gh an arc correspond+ to ! range ( advance & ret>d4 ,if ?is bru% is swung 9 a direction opposite to t ( ! revolution ( ! commutator1 ! metal portions w meet soon]1 ) ! result t ! sp>k w occur e>li]1 or w be advanc$4 ,if1 h[ev]1 ! bru% is swung to a po9t f>!r along 9 ! direction ( rotation ( ! commutator1 ! sp>k w occur lat]1 or w be ret>d$4 ,^! v>iations ( position ( ! bru% are g5]ally obta9$ by means ( a lev] atta*$ to ! /e]+ po/ or :eel4 ,x is evid5t t ! curr5t mu/ pass f ! bru% to ! metal segm5t ( ! commutator 9 ord] to complete ! circuit ?r\gh ! tim] & ?us =m ! sp>k4 ,x is ! prim>y curr5t1 or l[-t5sion curr5t f ! batt]y or magneto1 t passes ?r\gh ! tim]1 & z ?is is ( l[ voltage & is !re=e easily disc\rag$1 x is necess>y t ! contact po9ts be kept clean 9 ord] t its travel may be made easy4 ,tim]s are g5]ally protect$ f dirt1 b ! p>ticles t w naturally be worn (f f ! metal & rubb] commutator & bru% %\ld be clean$ out be=e its accumulation becomes deposit$ on ! contact po9ts & int]f]es ) p]fect electrical connection4 ,a few ye>s ago1 ! majority ( batt]y ignition sy/ems employ$ a sep>ate coil = ea* cyl9d] ( ! motor4 ,ea* coil 9 ?is sy/em is connect$ ) an individual bru% t op]ates aga9/ ! same commutator z d ! bru%es = ! o!r cyl9d]s4 ,) su* a sy/em1 ! prim>y circuit leads f "o t]m9al ( ! batt]y to ! prim>y w9d+ ( ! coil1 ?r\gh ?is & ! vibrator to ! bru% ( ! tim] res]v$ = t p>ticul> coil & cyl9d]1 & !nce ?r\gh ! swit* to ! o!r t]m9al ( ! batt]y4 ,?is ord] may be rev]s$1 or ! tim]1 swit*1 & coil may be plac$ 9 any consecutive position1 provid$ ! curr5t passes ?r\gh all 9 its travel f "o t]m9al ( ! batt]y to ! o!r4 ,! second>y1 or high-t5sion curr5t is l$ f ! t]m9al ( ! second>y w9d+ on ! coil to ! sp>k plug ( ! prop] cyl9d]4 ,!re %\ld be a gr\nd wire to s]ve = ! return ( ! second>y curr5t4 ,?is may lead f any "p ( ! prim>y circuit to a clean metal connection on ! motor4 ,! multiple coil sy/em is /ill us$ to a l>ge ext5t1 b an elaboration ( x w be f\nd on _m ( ! mod]n c>s4 ,?is consi/s ( ! use ( b a s+le coil = all ( ! cyl9d]s ( ! motor4 ,?is is done by means ( a di/ributor1 :i* is a sort ( glorifi$ tim] consi/+ ( a commutator provid$ ) z _m segm5ts z !re are cyl9d]s 9 ! motor4 ,?is di/ributor receives ! curr5t f a s+le coil & deliv]s x to ! prop] cyl9d] z ! v>i\s connections are made4 ,! tim] /ill p]=ms its function ( complet+ ! circuit f ! s\rce ( curr5t only at ! prop] in/ant1 & leaves ! di/ributor to s]ve ! purpose ( a swit* to sidetrack ! curr5t & deliv] x at ! v>i\s cyl9d]s 9 turn4 ,if x %\ld ev] become necess>y to remove any "p ( ! tim]1 or to *ange ! l5g? ( ! sp>k control rods1 ! greate/ c>e %\ld be tak5 to make c]ta9 t ! motor is prop]ly tim$ :5 ! v>i\s portions are replac$4 ,?is c be/ be done by sett+ ! sp>k lev] 9 its c5tral position1 remov+ a plug f "o ( ! cyl9d]s1 & introduc+ a rod or long screw driv] into ! op5+ = ! purpose ( det]m9+ ! exact top ( ! /roke ( ! pi/on4 ,:5 ! fly:eel is turn$1 ! top ( ! /roke %\ld be m>k$ on ! rod or screw driv] z ! latt] is =c$ upw>d by ! pi/on4 ,if ! sp>k plug is laid ) its l>ge nut re/+ on ! cyl9d] head1 & ! swit* is ?r[n1 ! "t ( ! occurr5ce ( ! sp>k c be readily obs]v$ z ! motor is turn$ sl[ly by h&4 ,?is sp>k %\ld occur 9 ?is p>ticul> plug j z ! pi/on ( t cyl9d] rea*es ! top ( its /roke1 z indicat$ by ! *ange 9 ! direction ( ! movem5t ( ! rod or screw driv]4 ,if ! sp>k occurs too soon or too late1 ! commutator %\ld be mov$ backw>d or =w>d to rem$y ! respective tr\ble4 ,al?\gh if ! tim] is set prop]ly = "o cyl9d] x is probable t ! sp>k 9 ! o!rs is also tim$ correctly1 x is well to te/ ea* to make c]ta9 t !re has be5 no unev5 we> 9 ! contact segm5ts ( ! commutator or ! bru%4 ,,*apt] ,v ,,magnetos ,! p]fection ( ! magneto & its application to c>s ( all classes & sizes has m>k$ ! mo/ important /ep 9 gasol9e motor ignition s9ce ! introduction ( ! electric sp>k4 ,! magneto is n[ consid]$ "o ( ! mo/ vital p>ts ( ! c>1 & :ile x is possible = ! motor to be run = _m miles on ! batt]ies t =m ! auxili>y ignition s\rces1 ! me*anical curr5t g5]ator has left ! field ( ! desirable accessories & has become an actual1 physical portion ( ! eng9e4 ,! op]ation ( ! magneto is simple1 its :ys & :]e=es are logical1 & if "o inve/igates ! subject1 ev5 sup]ficially1 he w discov] t ! mu*-malign$ ma*9e seldom gives tr\ble1 & t :5 x does1 su* action1 or failure to act1 is due to neglect1 abuse1 or "s o!r p]fectly legitimate reason1 r ?an pure cuss$ness on ! "p ( ! in/rum5t itself4 ,if ! m]e me*anical aspect is consid]$2 if x is realiz$ t ! magneto consi/s ma9ly ( a bundle ( wires :i*1 :5 revolv$ ne> ! ends ( a magnet1 collects t magnetism & s5ds x ?r\gh ! circuit 9 ! =m ( ! electric curr5t1 & t consequ5tly ! magneto is a conv]t] t *anges "p ( ! me*anical en]gy ( ! motor into ! sp>k-=m+ fluid1 ! *ief idea ( magneto pr9ciples may be m easily grasp$4 ,to be sure1 ! magneto is delicate1 & = t reason x %\ld nev] be dissect$ by ! amateur1 b inasmu* z :at few adju/m5ts x has are readily accessible1 x is seldom t ! ma*9e ne$ to be tak5 ap>t4 ,! plat9um po9ts ( ! contact break]1 usually locat$ 9 ! small box on ! end ( ! armature %aft1 may ne$ to be smoo!d ) em]y pap] occasionally if !y h become pitt$ f excessive sp>k+1 b ?is is a simple op]ation & is n greatly diff]5t f ! c>e giv5 to ! vibrator ( ! da%bo>d sp>k coil1 z describ$ 9 ! prec$+ *apt]4 ,a few drops ( oil %\ld be f$ to ! lubricat+ cups or holes ( ! armature %aft z (t5 z ! directions call =--usually ab\t once e five hundr$ miles--b aside f ?is1 ! own] c g5]ally =get t he has a magneto1 & w only be rem9d$ ( ! fact by ! pleas+ abs5ce ( ignition tr\ble4 ,if ignition tr\ble does occur1 x is m ?an probable t ! fault lies ) ! plugs1 tim]1 or wires1 r ?an ) ! magneto4 ,! man :o drives a magneto-equipp$ c> kn[s t ! curr5t produc] is run by a ge> connect$1 ei!r directly or ?r\gh ! m$ium ( o!r ge>s ) ! crank %aft ( ! motor4 ,he kn[s1 !n1 t ! magneto is driv5 positively & t !re is a con/ant relation betwe5 its spe$ & ! numb] ( revolutions ( ! motor4 ,b does he "k t x is absolutely necess>y t a c]ta9 position ( ! armature %all always correspond ) a simil> position ( ! crank %aft ( ! motor1 & t consequ5tly ! same tee? ( ! driv+ ge>s mu/ always me%8 ,he w mo/ assur$ly be made aw>e ( ?is if he disconnects 8 magneto & !n fails to replace ! ge>s s t exactly ! same tee? are 9 me%1 = ev5 ! diff]5ce ( a s+le too? betwe5 ! normal positions ( ! armature & crank %aft w prev5t ! magneto f deliv]+ a suffici5t sp>k to enable ! motor to run4 ,! reason = ?is is simple4 ,all ( ^! direct-driv5 magnetos are ( ! alt]nat+ curr5t type1 z ?is =m all[s ( ! simple/ con/ruction ( armature & w9d+s4 ,! alt]nat+ curr5t g5]ator obta9s its "n f ! fact t !re are no regul>ly-def9$ nor? & s\? poles at any "p ( ! circuit1 z ^! keep *ang+ cont9u\sly1 or alt]nat+4 ,dur+ ea* revolution ( ! armature ( ! alt]nat+ curr5t magneto1 !re are b two positions at :i* a curr5t w be =m$4 ,n[ ! sp>k 9 any cyl9d] ( a motor is requir$ at ab\t ! top ( ! compression /roke ( ! pi/on 9 t cyl9d]4 ,consequ5tly :5 ! pi/on is at ! top ( its compression /roke1 ready = ! sp>k t w ignite ! *>ge1 ! armature ( ! magneto mu/ be 9 "o ( its two curr5t-g5]at+ positions1 & !re mu/ !re=e be a con/ant relation betwe5 ! position ( ! crank %aft1 to :i* ea* pi/on is connect$1 & t ( ! revolv+ "p ( ! magneto4 ,if1 n[1 ! driv+ ge> ( ! magneto is return$ to its place )\t reg>d to ! tee? ( ! next ge> ) :i* x me%es1 x w be se5 t ! prop] relation betwe5 ! position ( ! armature & t ( ! crank %aft w n be ma9ta9$4 ,"u ^! conditions1 :5 ! pi/on is at ! top ( ! compression /roke1 ready = ! sp>k1 ! armature w n be 9 a position at :i* a curr5t c be g5]at$1 & !re c consequ5tly be no sp>k =m$ at ! plug4 ,conv]sely1 :5 ! armature has be5 revolv$ to ! position at :i* a curr5t w be =m$1 none ( ! pi/ons w be requir+ ! sp>k1 & ?is consequ5t lack ( team "w w prev5t ! op]ation ( ! motor4 ,9 ord] to ma9ta9 ?is team "w betwe5 ! armature ( ! magneto & ! crank %aft ( ! motor1 ! int]me%+ tee? ( ! ge>s %\ld be m>k$ ) a prick pun* be=e !y are remov$1 s t !y may be return$ to _! prop] place )\t tr\ble4 ,only 9 ?is mann] c accurate results be obta9$1 if x is at any "t necess>y to remove all or "p ( ! magneto driv+ ge>4 ,! magnets =m+ ! fields ( ! magneto 9 :i* ! armature revolves are ( ! p]man5t k9d2 t is1 !y d n dep5d ^u w9d+s & a sep>ate electric curr5t = _! excitation1 z is ! case ) "s ( ! l>g] g5]ators4 ,^! magnets may be consid]$ to be ! mo/ fai?ful "p ( ! ma*9e1 = !y g5]ally reta9 _! /r5g? "u all conditions ( re/ or "w1 & x is ^u !m t ! prop] op]ation ( ! magneto l>gely dep5ds4 ,a magneto 9 :i* ! magnets h become weak5$ is useless = ignition purposes until ! fields c be remagnetiz$1 & z ?is c only be done at ! factory1 ! ma*9e 9 its entirety mu/ be remov$ f ! motor4 ,x is a comp>atively easy matt] to det]m9e :e!r or n ! fields h lo/ _! magnetism by plac+ a piece ( iron or /eel )9 close range ( ! base or sides ( ! magneto4 ,an appreciable pull w be ex]t$ by ! magnets if !y /ill reta9 _! /r5g?1 al?\gh x is n to be suppos$ t ! =ce ?us exhibit$ w be v vigor\s f su* a small ma*9e4 ,if ! magneto has be5 disconnect$ f its driv+ ge> = any reason1 ! am\nt ( magnetism rema9+ 9 ! fields w be be/ det]m9$ by turn+ ! armature %aft ) ! h&4 ,a resi/ance %\ld be (f]$ to ! turn+ at fir/ until a c]ta9 po9t is rea*$1 aft] :i* ! armature %\ld exhibit a /rong t5d5cy to fly =w>d to a new position1 "o hundr$ & eighty degrees beyond its =m] normal position ( re/4 ,?is activity ( ! armature is "o ( ! be/ guides to ! am\nt ( magnetism rema9+ 9 ! fields4 ,_m magnetos t h be5 in/all$ on old motor c>s n previ\sly s equipp$ are ( ! friction-driv51 direct-curr5t type t produces a uni=m sp>k at any po9t ?r\gh\t ! armature revolution4 ,curr5t f ^! may be us$ to *>ge a /orage batt]y = ! op]ation ( electric lights or to supply auxili>y ignition curr5t = />t+4 ,! positively-driv51 alt]nat+-curr5t magneto may also be us$ to op]ate electric lights on ! c>1 b ?is type ( curr5t _c be /or$ 9 a batt]y1 & consequ5tly ! lights are available only :5 ! motor is runn+4 ,! magneto1 h[ev]1 is n prim>ily an electric-light+ outfit1 & unless x is especially design$ = ! d\ble purpose1 a sep>ate ma*9e %\ld g5]ally be us$ = supply+ illum9at+ curr5t4 ,,*apt] ,,vi ,,c>buretors ,,& ,,_! ,,fuel ,al?\gh gasol9e is inflammable 9 its liquid /ate1 its combu/ion is n suffici5tly rapid to approa* ! explosive po9t necess>y to r5d] its en]gy available 9 ! automobile eng9e cyl9d]4 ,! prop] proportion ( gasol9e vapor & air1 h[ev]1 =ms a mixture t is highly inflammable & t w be entirely consum$ 9 ! eng9e cyl9d] "u ord9>y conditions )9 ab\t "o-tw5tie? ( a second aft] ! =mation ( ! sp>k4 ,?is rapid combu/ion s ne>ly approa*es ! in/antane\s action ( an explosion t x may be consid]$ z su* 9 all ord9>y discussions ( ! gasol9e eng9e4 ,lit]ally1 h[ev]1 ! gasol9e eng9e is n an explosion motor1 b r is x an eng9e ( ! int]nal combu/ion type4 ,to obta9 ?is gasol9e vapor 9 an easily-controll$ =m ! c>buretor 0 design$ z "o ( ! mo/ important adjuncts ( ! automobile4 ,! fir/ =m ( c>buretors1 or vaporiz]s1 z !y 7 call$ !n1 employ$ a flat1 wov5 lamp wick ov] :i* ! gasol9e fl[$4 ,?is spread ! fuel out ov] a comp>atively l>ge surface & r5d]$ evaporation rapid & simple4 ,! *amb] conta9+ ?is wick 0 plac$ 9 ! l9e ( ! intake pipe ( ! motor & 0 connect$ ) ! cyl9d]s on ! desc5t ( ! pi/ons on ! suction /roke ?r\gh ! m$ium ( ! v>i\s inlet valves4 ,9 a f\r-cycle motor1 ! pi/on acts z a suction pump on alt]nate d[n-/rokes & s]ves to draw ! *>ge into ! cyl9d]4 ,?is suction creat$ ! necess>y curr5t ( air to facilitate evaporation ( ! gasol9e on ! wick1 & by regulat+ ! size ( ! passages1 ! prop] proportion ( air & gasol9e vapor c\ld be obta9$4 ,! mod]n1 high-spe$ automobile motor1 ) its v>y+ dem&s ^u ! c>buretor1 creat$ ! necessity = a m delicate1 flexible1 & compact vaporiz] ?an 0 to be f\nd 9 ! lamp wick type4 ,consequ5tly ! wick 0 replac$ by a small1 sl5d]1 holl[ tube hav+ a cone-%ap$ op5+ at its upp] end ?r\gh :i* ! gasol9e f ! fe$ pipe 0 made to pass4 ,fitt+ into ! upp] end ( ?is tube1 & po9t$ to ! same angle1 0 a cone-%ap$ ne$le t c\ld be mov$ 9 & out ( ! op5+4 ,if ?is ne$le 0 unscrew$ slightly s t x did n =m a tight fit ) ! end ( ! tube1 a small r+ w\ld be =m$ ?r\gh :i* ! gasol9e mu/ pass :5 suck$ by ! alt]nate d[n /rokes ( ! pi/ons4 ,?is tube & ne$le con/itute1 "u v>i\s guises1 ! ne$le valve ) :i* practically e mod]n c>buretor is equipp$4 ,:5 ! gasol9e1 ru%+ ?r\gh ! small tube1 /rikes ! re/rict$ op5+ ( ! ne$le valve1 x is brok5 up into a f9e spray :i*1 "u prop] conditions1 w become vaporiz$ almo/ z soon z x comes 9 contact ) a curr5t ( air4 ,?is air curr5t is induc$ by ! same pump-l effect ( ! pi/ons z t :i* sucks ! gasol9e ?r\gh ! ne$le valve1 & ?us x occurs only :5 ! *>ge is desir$ 9 ! cyl9d]s4 ,b ! c>buretor is n m]ely to provide a compact device = vaporiz+ ! gasol9e1 = x mu/ also furni% a means ( regulat+ ! proportion ( gas to air4 ,gasol9e vapor is only highly inflammable :5 mix$ ) ! prop] quantity ( air1 & if ?is proportion is v>i$ above "o limit or bel[ ano!r1 ignition ( ! *>ge w n occur 9 ! cyl9d]s4 ,9 fact1 ! all[able v>iation 9 ! proportion ( gasol9e vapor to air is re/rict$ betwe5 v n>r[ limits1 & %\ld n *ange m ?an f\r or five p] c5t4 f "o extreme to ! o!r4 ,! proportion ( gasol9e vapor to air by weight is ab\t "o to elev51 al?\gh ?is w v>y some:at ) ! diff]5t grades ( fuels4 ,! po9t to be emphasiz$1 h[ev]1 is ! fact t ! prop] proportion ( air to gasol9e vapor1 h[ev] x may v>y ) diff]5t grades1 %\ld be kept con/ant at all spe$s ( ! motor :5ev] t p>ticul> grade ( fuel is us$4 ,by volume1 ab\t #ig p] c5t4 ( ! mixture %\ld be air & ! rema9d] gasol9e vapor1 & x is ! device t w ! mo/ ne>ly ma9ta9 ?is proportion "u all conditions ( spe$1 temp]ature1 & air pressure t w prove to be ! mo/ delicate & flexible c>buretor4 ,a c>buretor may be adju/$ = diff]5t motors1 or = diff]5t op]at+ conditions ( ! same motor1 by means ( ! ne$le valve4 ,! f>!r end ( ! slim rod on :i* ! ne$le po9t is m\nt$ t]m9ates 9 a ?read & f+] nut t projects ?r\gh ! %ell ( ! c>buretor4 ,by turn+ ?is nut 9 "o direction1 ! ne$le valve is screw$ up t[>d ! cone-%ap$ end ( ! tube & ! orifice ?r\gh :i* ! gasol9e may pass is ?us r$uc$ 9 size4 ,?is w decrease ! am\nt ( gasol9e spray$ into ! air passage & w consequ5tly *ange ! composition ( ! mixture4 ,?is1 h[ev]1 %\ld n be confus$ ) ?rottl+ ! motor4 ,:5 ! ne$le valve is tight5$1 ! volume ( ! mixture pass+ to ! cyl9d]s is ! same1 = x is only ! proportion ( gasol9e vapor 9 t mixture t is *ang$4 ,?rottl+ consi/s 9 re/rict+ ! size ( ! op5+ ?r\gh :i* ! mixture passes1 & ?us limits ! am\nt ( ! *>ge t rea*es ! cyl9d]s at ea* suction /roke ( ! pi/on4 ,?rottl+ is us$ to r$uce ! p[]--& consequ5tly ! spe$--develop$ by ! motor1 :ile a decrease 9 ! am\nt ( gasol9e suppli$ to ! air ?r\gh ! ne$le valve may s]ve to increase ! p[] ?r\gh an improvem5t 9 ! nature ( ! mixture4 ,s9ce ! gasol9e vapor1 by volume1 =ms only ab\t ?ree p] c5t4 ( ! explosive mixture admitt$ to ! cyl9d]s1 a slight v>iation 9 ! size ( ! ne$le valve op5+ w result 9 a m>k$ *ange 9 ! composition ( ! *>ge & may make all ! diff]5ce betwe5 poor & p]fect runn+ ( ! motor4 ,consequ5tly ! ne$le valve nut %\ld be mov$ b ! small fraction ( a turn = ea* adju/m5t4 ,a motor :i* may refuse absolutely to run at "o position ( ! ne$le valve may give p]fect results if ! nut is unscrew$ b ! eigh? ( a turn4 ,9 view ( ! m>k$ diff]5ce 9 ! results obta9$ f ! use ( mixtures t are j "r1 & ^? :i* v>y b a slight p]c5tage 9 ! proportion ( gasol9e vapor to air1 x may be well to exam9e1 sup]ficially1 ! effects ( ri* & weak *>ges1 & !refrom to obta9 a li/ ( symptoms :i* may aid u to diagnose motor tr\ble prop]ly4 ,we all "k t air--or oxyg5--is requir$ to support combu/ion4 ,snuff+ a c&le is m]ely cov]+ its end s t air _c rea* ! flame4 ,= ! same reason1 gasol9e 9 a cov]$ tank _c burn1 no matt] h[ great ! heat appli$ to x4 ,! heat ( ! electric sp>k 9 ! cyl9d]1 al?\gh int5se1 does n cov] a suffici5tly l>ge area to ignite any *>ge except t compos$ ( ! prop] proportion ( gasol9e vapor & air4 ,if !re is too mu* gasol9e vapor1 mak+ a ri* mixture1 !re w n be suffici5t air 9 ! *>ge to support ! entire combu/ion ( ! gas1 & ! burn+ w be sl[--if x takes place at all4 ,! same conditions w prevail if !re is an insuffici5t supply ( air = a giv5 quantity ( gasol9e vapor1 & consequ5tly a ri* mixture may be obta9$ by r$uc+ ! air fl[ z well z by add+ to ! am\nt ( gas admitt$ to ! mix+ *amb]4 ,a ri* mixture w cause irregul> explosions 9 ! cyl9d]s1 & w (t5 emit a black1 pung5t smoke at ! exhau/4 ,! motor w probably ov]heat easily1 due to ! sl[-burn+ prop]ties ( ! mixture & ! result+ fact t a l>ge portion ( ! cyl9d] walls uncov]$ by ! pi/ons w be expos$ to ! flame4 ,9 "s in/ances1 ! cyl9d]s w miss fire at regul> int]vals1 ?us *ang+ ! syn*ronism ( ! impulses ) a well-def9$ & p]iodic skip 9 ! s\nd ( ! explosions4 ,:ile ^! are by no means c]ta9 symptoms ( a ri* mixture1 ! fir/ te/ to be made %\ld be to tight5 ! ne$le valve adju/m5t slightly :5 ! motor is runn+ & to note any result+ improvem5t 9 ! regul>ity ( ! explosions4 ,x may sometimes be difficult to di/+ui% betwe5 ! symptoms ( a ri* & a weak mixture1 b ! readju/m5t ( ! ne$le valve z j describ$ w at lea/ s]ve to locate ! tr\ble or to elim9ate "o or ! o!r possibility f consid]ation4 ,:5 a mixture is />v$1 or :5 !re is an insuffici5t supply ( gasol9e vapor to unite ) ! air admitt$ to ! cyl9d]s1 ! *>ge w n be highly inflammable & may n be ignit$ by ! small sp>k =m$ at ! plug4 ,ev5 :5 ignition does take place1 ! result+ p[] impulse w be weak because ( ! comp>atively small am\nt ( pressure-produc+ gas 9 ! mixture4 ,! explosions may occur regul>ly = a :ile1 b !re w be a m>k$ decrease 9 ! p[] develop$ by ! motor1 & ow+ to ! fact t weak mixtures may be sl[-burn+1 back-fir+ w (t5 result 9 "s eng9es to :i* su* a *>ge has be5 f$4 ,on ! o!r h&1 if a motor w run at all on a weak mixture1 x w produce bett] results ?an w\ld be ! case 7 ! *>ge too ri* 9 gasol9e vapor4 ,consequ5tly ! ne$le valve %\ld be clos$ z mu* z is consi/5t ) smoo? runn+ ( ! motor1 b ! mom5t a loss ( p[] or irregul> explosions occur1 ! mixture %\ld be enri*$4 ,at l[ spe$s ( ! motor1 ! pump+ action ( ! pi/ons is n z great z is ! case at high revolutions1 & consequ5tly ! suction draw+ ! gasol9e ?r\gh ! ne$le valve is dim9i%$4 ,= ?is reason1 ! ne$le valve op5+ mu/ be made l>g] or ! air passage re/rict$ = sl[ spe$s ( ! motor1 & x 0 consequ5tly necess>y1 on ! old1 non-automatic vaporiz]s1 to increase ! gasol9e supply :5ev] ! revolutions ( ! motor 7 to be r$uc$4 ,! mod]n c>buretor is suffici5tly automatic 9 its action to provide ! prop] mixture )9 wide ranges ( spe$ *ange ( ! motor1 b ev5 n[adays x is (t5 f\nd necess>y to increase ! gasol9e supply or to r$uce ! am\nt ( air admitt$ to ! intake pipe :5ev] x is desir$ to ?rottle ! motor d[n to a v l[ numb] ( revolutions p] m9ute4 ,! automatic action ( ! ord9>y c>buretor is obta9$ by increas+ ! air supply at high] spe$s ( ! motor4 ,consequ5tly ! motori/ w realize t :5ev] ! ne$le valve is to be set1 su* regulation %\ld be made :5 ! motor is well ?rottl$1 = if an ample gasol9e supply is obta9$ at l[ spe$s1 ! mixture w c]ta9ly be suffici5tly ri* at increas$ revolutions4 ,if1 on ! o!r h&1 ! c>buretor %\ld be set to supply a prop] mixture at high spe$s1 ! mixture w\ld be impov]i%$ :5 ! motor is ?rottl$1 & irregul> runn+ w\ld result4 ,! air = ! op]ation ( ! motor at ord9>y spe$s is suppli$ ?r\gh a fix$ op5+ 9 ! c>buretor connect$ ) ! *amb] into :i* ! gasol9e spray is introduc$4 ,9 addition to ?is1 mo/ c>buretors are suppli$ ) an auxili>y air op5+ :i* s]ves to furni% ! additional air necess>y = ! mixture at high spe$s ( ! motor4 ,! fix$ op5+1 be+ re/rict$ 9 size1 _c admit ! increas$ quantity ( air dem&$ by ! high] spe$s ( ! motor4 ,! auxili>y op5+ is provid$ ) "s =m ( automatic valve :i* may consi/ ei!r ( a s]ies ( ball *ecks1 a spr+-actuat$ mu%room valve1 or a s]ies ( special valves1 ea* ( :i* op5s at successively increas$ spe$s ( ! motor4 ,all ( ^! devices op]ate on ! same pr9ciple1 h[ev]1 & all[ ! increas$ suction ( ! motor to add to ! size ( ! air passage automatically--ei!r by ! f>!r op5+ ( a s+le valve1 or by ! successive op5+ ( diff]5t valves4 ,"s c>buretors are provid$ ) an adju/m5t by means ( :i* ! delicacy1 or ease ( op5+1 ( ! auxili>y air valve may be regulat$4 ,?is may be done by means ( a nut & screw :i* w increase or decrease ! t5sion ( ! controll+ spr+4 ,if ?is spr+ is set ) a high t5sion1 ! auxili>y valve w act only :5 ! motor is ex]t+ great suction1 or at fa/ spe$s4 ,! regulation ( ! auxili>y valve is an adju/m5t t %\ld be made only aft] ! ne$le valve has be5 set prop]ly = sl[ spe$s ( ! motor4 ,:5 ?is condition is obta9$1 ! ?rottle %\ld be op5$ & ! fur!r adju/m5t ( ! c>buretor = high spe$s ( ! motor %\ld !n be made ?r\gh ! auxili>y air valve4 ,9 o!r words1 ! ne$le valve %\ld be set s t ! motor runs prop]ly at l[ spe$s1 :ile ! adju/m5t ( ! auxili>y air valve %\ld be made only to secure smoo? op]ation at a high numb] ( revolutions4 ,x is n to be und]/ood t less gasol9e is actually requir$ at high spe$s ( ! motor because ! supply (t5 ne$s to be cut d[n at ! ne$le valve "u ^! conditions4 ,! actual am\nt requir$ at high spe$s is1 ( c\rse1 great] ?an is ! case at sl[1 on acc\nt ( ! great] numb] ( explosions 9 ! =m] in/ance4 ,b ! suction ( ! motor g5]ally increases ! gasol9e fl[ beyond ! dem&s ( ! cyl9d]s at high spe$s1 & x is = ?is reason t ! automatic auxili>y air supply is provid$ to furni% ! additional air requir$ to support combu/ion4 ,9 fact1 at heavy loads1 :5 ! total am\nt ( gasol9e consum$ mu/ be great1 a second>y jet ( fuel is br\ght into action 9 "s c>buretors4 ,?is is kn[n z ! multiple-jet type & is f\nd on "s ( ! l>ge eng9es t mu/ possess a spe$ & p[] v>iation betwe5 wide ranges4 ,! action ( ^! v>i\s jets is entirely automatic & is dep5d5t ^u ! spe$ & fuel requirem5ts ( ! motor4 ,7 ! gasol9e f$ directly f ! fuel tank to ! ne$le valve ( ! c>buretor x is evid5t t ! rate ( fl[ ( ! liquid w\ld dep5d1 to a l>ge ext5t1 ^u ! am\nt 9 ! tank & ^u ! position ( ! c>4 ,?is w\ld cause ea* *>ge to diff] 9 ! proportion ( gasol9e vapor to air1 & x is h>dly probable t ! motor c\ld be run at all "u su* conditions4 ,9 ord] t ! pi/ons may suck ! gasol9e f a level t does n v>y ) ! am\nt ( fuel 9 ! tank or ! position ( ! c>1 a sep>ate comp>tm5t is provid$ 9 ! c>buretor4 ,?is is kn[n z ! float *amb]1 & x is f ?is comp>tm5t t ! gasol9e passes ?r\gh ! ne$le valve into ! vaporiz+ or mix+ *amb]4 ,a cork or holl[ metal float is plac$ 9 ?is float *amb] & is m\nt$ on a lev] connect$ ) a valve locat$ at ! end ( ! gasol9e fe$ pipe4 ,z ! gasol9e is admitt$ to ! *amb]1 ! float rises & closes ! valve controll+ ! fl[ ( fuel4 ,z ! gasol9e is suck$ ?r\gh ! ne$le valve f ! float *amb]1 ! float 9 ! latt] l[]s1 & ! fuel is aga9 admitt$ by ! op5+ ( ! above-describ$ valve4 ,! float & valve are exce$+ly delicate 9 _! op]ation & ! gasol9e is ?us kept at a con/ant level 9 ! *amb] "u all conditions ( ! c> & tank4 ,! /em ^u :i* ! float ( "s c>buretors is m\nt$ is sometimes ?read$ & provid$ ) a nut by means ( :i* ! float may be rais$ or l[]$4 ,?is furni%es an adju/m5t = v>y+ ! level 9 ! float *amb] & det]m9+ at :at po9t ! fl[ ( gasol9e %all be cut (f by ! automatic valve4 ,! float is suppos$ly prop]ly regulat$ :5 ! c>buretor leaves ! factory1 b ! /em may become b5t or ! c>buretor may be appli$ to a motor o!r ?an t = :i* x 0 orig9ally design$4 ,9 ei!r ( ^! ev5ts1 x may be f\nd necess>y to raise or l[] ! float be=e ! prop] level ( gasol9e c be ma9ta9$ 9 ! *amb]4 ,if ! float is too high on its /em1 ! gasol9e control valve may n be op]at$ until ! fuel ov]fl[s 9 its *amb]4 ,?is is kn[n z a flood$ c>buretor & produces a ri* mixture :i* w ultimately prev5t ! prop] op]ation ( ! motor4 ,turn+ d[n ! gasol9e supply at ! ne$le valve w n rem$y ?is1 = ! fuel w rea* ! vaporiz+ *amb] by ano!r r\te4 ,a flood$ c>buretor (t5 gives tr\ble1 & :ile x may be rem$i$ easily1 ! amateur may exp]i5ce difficulty 9 locat+ its s\rce4 ,z soon z x is discov]$ t a c>buretor has become flood$1 ! ne$le valve %\ld be tight5$ s t no gasol9e c pass ?r\gh x1 & ! motor %\ld !n be crank$4 ,?is w s]ve to evaporate ! excess gasol9e 9 ! float *amb] & r$uce ! level to ! po9t at :i* x w n ov]fl[4 ,! exact numb] ( turns & fractions ( turns ?r\gh :i* ! ne$le valve nut 0 mov$ %\ld h be5 not$ 9 ord] t ! valve may be reset to its orig9al position aft] ! surplus fuel has be5 crank$ out4 ,a float t is set too l[ on its /em w close ! fuel supply valve be=e a suffici5t am\nt ( ! fuel has fl[$ into ! *amb]1 & w =m a lean mixture at high spe$s ( ! motor--ev5 ?\gh ! ne$le valve %\ld be op5$ wide4 ,! obvi\s rem$y = su* a condition is to raise ! float until ! gasol9e w be ma9ta9$ at ! prop] level4 ,if !re is no nut & screw adju/m5t by :i* ! float may be rais$1 ! arm to :i* x is atta*$1 & :i* is connect$ ) ! valve1 may be b5t slightly4 ,b ! motori/ %\ld n jump at conclusions & assume t ! float is improp]ly set ! mom5t ! c>buretor beg9s to flood or ! motor appe>s to />ve at high spe$4 ,! fir/ condition may be caus$ by a piece ( dirt or o!r =eign matt] t may h become lodg$ on ! valve seat & prev5t$ ! valve f clos+ :5 ! gasol9e rea*$ ! prop] level 9 ! float *amb]4 ,?is w produce exactly ! same results z w a high float & is a tr\ble t w m (t5 occur 9 ! av]age c>buretor4 ,! difficulty may g5]ally be rem$i$ easily by dra9+ ! gasol9e f ! float *amb] aft] ! valve 9 ! ma9 supply pipe has be5 turn$ (f4 ,! (f5d+ =eign matt] w g5]ally be c>ri$ ) ! gasol9e z ! latt] is dra9$1 & ! valve 9 ! fe$ pipe may aga9 be op5$ z soon z ! dra9 cock is %ut (f4 ,if ?is fails to rem$y matt]s1 x is probable t ! difficulty lies ) ! float4 ,a clogg$ gasol9e pipe or dirty /ra9] w produce ! same effect on ! op]ation ( ! motor z w a float t is set too l[ on its /em4 ,:5 ! motor seems to />ve at high spe$1 & x is evid5t t !re is suffici5t gasol9e 9 ! tank1 ! union %\ld be disconnect$ at ! po9t :]e ! fe$ pipe jo9s ! c>buretor4 ,if !re appe>s to be an ample fl[ ?r\gh ?is pipe :5 ! ma9 valve is op5$1 x is probable t ! /oppage has occurr$ 9 ! /ra9]4 ,if ! fl[ ?r\gh ! ma9 fe$ pipe is n free1 h[ev]1 x is possible t ! v5t hole 9 ! fill] cap on ! tank has become /opp$ or t ! latt] has be5 screw$ d[n too tightly4 ,9 ! gravity fe$ sy/ems1 "s me?od mu/ be provid$ to all[ ! air to fl[ into ! tank to replace ! gasol9e f$ to ! c>buretor4 ,if !re is no hole 9 ! fill] cap1 ! latt] %\ld n be screw$ d[n s tightly t an airtight jo9t w be =m$4 ,probably ! simple/ me?od ( det]m9+ :e!r ! tr\ble lies 9 a l[ float is to prime ! c>buretor & to obs]ve ! ease ) :i* ?is c be done & its effect ^u ! eng9e4 ,ne>ly e c>buretor is provid$ ) a flu%+ or prim+ p9 by means ( :i* ! float c be depress$ s t ! gasol9e *amb] w be fill$ rapidly to a po9t above its normal level4 ,?is is useful 9 />t+1 z ! desir$ ri* mixture is quickly obta9$ )\t an undue am\nt ( crank+4 ,if ! c>buretor flu%es easily1 x is evid5t t !re is no s]i\s /oppage 9 ! pipe4 ,if ?is easy flu%+ is foll[$ by good runn+ on ! "p ( ! motor1 & if ?is1 9 turn1 is succe$$ by gradually-dim9i%+ impulses indicat+ a weak5+ mixture1 x is q evid5t t ! float is prev5t+ ! fl[ ( ! gasol9e at ! prop] "t4 ,9 addition to ! flu% p9 f\nd on c>buretors1 _m are provid$ ) o!r devices to r5d] />t+ easy4 ,x is well kn[n t a high-te/ gasol9e1 su* z a #gf1 w vaporize m easily ?an w "o ( a l[] degree ( specific gravity4 ,also1 e motori/ has _h impress$ ^u him ! fact t heat aids 9 ! vaporization ( gasol9e4 ,if we try to />t a motor on a cold morn+ ) a l[-grade gasol9e1 su* z ! #fj- or #fb-;degree fuel n[ g5]ally obta9$1 we "k t a rag dipp$ 9 hot wat] & w\nd ar\nd ! c>buretor w help matt]s4 ,to enable l[ grades ( fuel to be prop]ly vaporiz$ "u all runn+ conditions1 _m c>buretors are provid$ ) a wat] jacket surr\nd+ ! vaporiz+ *amb]4 ,?is jacket is connect$ ) ! cool+ sy/em ( ! motor1 & ! hot wat] surr\nd+ ! *amb] s w>ms ! int]ior t vaporization is greatly facilitat$4 ,"s ( ^! sy/ems are provid$ ) a %ut-(f cock by means ( :i* ! c>buretor may be op]at$ ) hot wat] 9 ! jackets1 or n1 z desir$4 ,o!r c>buretors employ a jacket surr\nd+ ! exhau/ pipe ( ! motor & connect$ ) ! vaporiz+ *amb]4 ,! air is heat$ by ! hot exhau/ pipe z x is suck$ into ! c>buretor1 & ?is also facilitates ! vaporization ( ! fuel4 ,"s c>buretors are provid$ ) bo? jacket sy/ems1 :ile o!rs h nei!r1 b :atev] design is in/all$1 ! be/ results w be obta9$ if cold air is us$ aft] ! motor is once />t$4 ,cold air is m conc5trat$ & conta9s a great] am\nt ( oxyg5 p] cubic foot ?an does air t has be5 exp&$ by heat1 & consequ5tly _m c>buretors are provid$ ) a means ( turn+ (f ! hot air aft] ! motor is />t$4 ,! high] ! degree ( specific gravity ( a fuel on ! ,baum scale1 ! m volatile w x be1 & consequ5tly a #fh gasol9e w vaporize m easily & give m p[] ?an w a #fj or #fb fuel4 #gb gasol9e is (t5 us$ 9 races1 b ! av]age motori/ does n get bett] ?an #fd--;& he is sometimes lucky to obta9 fuel ( t specific gravity4 ,a hydromet]1 or specific gravity te/]1 is a conv5i5t in/rum5t = ! av]age motori/ to own1 & ) x he may tell exactly :at grade ( fuel he is pay+ =4 ,! ,baum scale1 by :i* all gasol9e is te/$1 reads 9 degrees1 & ! specific gravity is obta9$ by obs]v+ ! dep? to :i* ! hydromet] s9ks 9 ! liquid4 ,?is in/rum5t resembles some:at a glass !rmomet]1 & is s graduat$ t ! deep] x s9ks 9 a liquid1 ! high] w be ! read+ on its scale4 ,wat] 9 ! fuel is an annoyance t is (t5 enc\nt]$ by ! automobili/ & ! motor boatman1 & ?is w make its pres5ce kn[n by caus+ ! motor to skip :5 all adju/m5ts & connections seem to be 9 p]fect condition4 ,wat] is mu* heavi] ?an gasol9e & has no aff9ity = x1 & consequ5tly1 z x s9ks to ! bottom ( ! tank1 a few drops 9 a l>ge am\nt ( gasol9e w cause tr\ble by pass+ out ?r\gh ! ne$le valve at int]mitt5t int]vals & =m+ an unexplosive mixture4 ,! pres5ce ( ! wat] 9 ! fuel may be detect$ easily )\t ! use ( a hydromet] by draw+ "s gasol9e f ! bottom ( ! tank into a t9 or :ite-enamel$ cup4 ,if wat] is pres5t1 x may be se5 9 ! =m ( small globules 9 ! bottom ( ! cup4 ,if ! cont5ts ( ! cup are p\r$ ov] a flat surface s t ! liquid may be all[$ to spread1 ! gasol9e w be se5 to cov] a l>ge surface & evaporate quickly1 :ile ! wat] w seem to rema9 9 ! globules unevaporat$ = "s "t aft] ! gasol9e has disappe>$4 ,?is latt] te/ w sometimes %[ ! pres5ce ( wat] :5 none c be disc]n$ 9 ! bottom ( ! cup be=e ! cont5ts are p\r$ out on ! flat surface4 ,! practice ( dop+ ! fuel tank by add+ to ! gasol9e e!r or "s o!r highly volatile liquid is n to be recomm5d$ to ! av]age motori/4 ,a few ounces ( e!r or *lor(orm add$ to ! fuel w =m a m volatile & consequ5tly m p[]ful mixture1 b unless ! greate/ c>e is tak51 ! motor is liable to be completely ru9$ by su* a proc$ure4 ,num]\s cases are on record 9 :i* cyl9d] heads h be5 bl[n (f or ca/+s crack$ by ! =ce ( "s ( ! explosions :5 too mu* dope has f\nd its way into ! mixture4 ,al?\gh ! av]age motor gasol9e obta9able n[adays is h>dly all t c\ld be desir$ z automobile fuel1 a little c>e tak5 :5 fill+ ! tank w elim9ate _m ( ! c>buretor annoyances to :i* _m c>s seem to be subject4 ,! cap ( ! tank %\ld nev] be tak5 (f :5 ! air is fill$ ) p>ticles ( du/ t are liable to f9d _! way into ! fuel1 & c>e %\ld be tak5 to see t no pieces ( ! rubb] or lea!r wa%] or pack+ drop into ! gasol9e :5 ! cap is remov$4 ,=eign matt] & wat] t may be 9 ! gasol9e :5 pur*as$ may be remov$ by /ra9+ ! fuel ?r\gh a *amois sk9 plac$ inside ( ! funnel ?r\gh :i* ! tank is fill$4 ,,*apt] ,,vii ,,lubrication ,a lubricant acts z a sort ( pacifi] betwe5 two surfaces t w\ld o!rwise move 9 contact ) ea* o!r4 ,no surface c move 9 direct contact ) ano!r ( ! same or a diff]5t mat]ial )\t ! g5]ation ( heat2 b ! am\nt ( heat g5]at$1 or resi/ance met )1 is det]m9$ by ! nature ( ^! two rubb+ surfaces4 ,! oil1 or grease1 or :atev] suave1 slipp]y sub/ance is to be us$ z a lubricant1 int]poses itself 9 a ?9 film betwe5 ! two rubb+ surfaces & smoo?s matt]s ov]1 z x 74 ,if a suffici5t am\nt ( ?is me*anical soo?+ syrup is n f$ to ! rubb+ surfaces1 ! temp] & temp]ature ( ea* w be rais$ to ! po9t :]e !y w cl9*1 & mu* "t & ef=t may be requir$ be=e h>mony c aga9 be re/or$4 ,?us x is actually ^u a film ( lubricant t a %aft re/s1 r ?an ^u ! be>+1 or box1 9 :i* x turns4 ,if ! be>+ is set s tight t !re is no room = ! int]position ( an oil film1 ! %aft & j\rnal w at once heat4 ,! great] ! pressure ( ! %aft 9 its box1 ! ?ick]1 or heavi]1 %\ld be ! lubricant us$1 = a light oil w\ld be squeez$ out or brok5 d[n m easily ?an w\ld "o t possesses great] viscosity4 ,! coeffici5t ( friction may be t]m$ ! me*anical am\nt ( irritability g5]at$ :5 two surfaces are rubb$ toge!r4 ,?us if two metals are rubb$ toge!r1 ?is figure is high1 & a l>ge am\nt ( friction1 or heat1 w be g5]at$4 ,a metal rubb+ ov] oil1 h[ev]--z is ! case ) a well-lubricat$ be>+--w ar\se b little res5tm5t & its pa?way w be made smoo? & easy1 = ! coeffici5t ( friction ( ^! two mat]ials is l[4 ,! l[] ?is figure c be kept1 ! m easily c ! surfaces be rubb$ ov] ea* o!r & ! high] w be ! effici5cy ( ! be>+4 ,apply ?is to e be>+ or rubb+ surface ( a motor1 & we see t prop] lubrication affects n only ! l5g? ( life ( ! mov+ p>ts1 b ! ease ) :i* ! eng9e c be run & ! consequ5t p[] developm5t4 ,?us1 a lubricant t w prev5t we> betwe5 ! mov+ p>ts may be suppli$ to ! be>+s & pi/ons ( a motor1 & "u ?is condition ! eng9e might la/ indef9itely2 b ?is oil might be s visc\s or possess s high a coeffici5t ( friction t ea* be>+ w\ld turn ) difficulty & mu* ef=t w\ld be requir$ to run ! motor be=e x c\ld beg9 to develop p[]4 ,b ! introduction ( oil to a be>+ n only r$uces ! friction betwe5 ! surfaces t w\ld o!rwise move 9 contact ) ea* o!r1 b x s]ves ano!r v important purpose4 ,e prop]ly-lubricat$ portion ( a motor ei!r moves 9 a ba? ( oil or is connect$ ) an oil res]voir s t a c]ta9 am\nt w be f$ regul>ly to ! rubb+ surfaces4 ,!re is always "s heat g5]at$ 9 a be>+1 no matt] h[ well x may be lubricat$1 & ! cont9u\s fl[ or circulation ( ! oil s]ves to c>ry (f ?is heat t w\ld o!rwise t5d to dry ! lubricant if !re 7 no fre% supply4 ,! prop] lubrication ( ! motor is ev5 m necess>y ?an is ! adju/m5t ( ! c>buretor or ! condition ( ! ignition sy/em4 ,to be sure1 if ei!r ! c>buretor or ! ignition sy/em is out ( ord]1 ! motor w n run1 b no actual h>m to ! me*anism w result f ?is fact4 ,on ! o!r h&1 a motor may be run indef9itely ) a defective lubricat+ sy/em1 & no app>5t h>m w result--until ! end ( t indef9ite "t arrives & x is f\nd t ! ma*9e is a fit subject = a junk heap4 ,let u see h[ _m p>ts ( ! motor are rea*$ by ! gallon or s ( oil t we p\r into ! tank4 ,a six-cyl9d] motor may h sev5 crank %aft be>+s2 x w c]ta9ly possess six connect+ rods1 ea* ( :i* w be provid$ ) a be>+ at bo? its l>ge & small ends--or twelve 9 all2 !re may be two cam %afts1 ea* ) five be>+s & half a doz5 cams2 ^! w require1 toge!r ) ! magneto & pump %afts1 five or six ge>s 9 ! =w>d tra92 & ! six pi/ons w dem& _! %>e ( att5tion f ! lubricat+ sy/em4 ,"h is a gr& total ( ov] fifty rubb+ surfaces on a l>ge motor1 & ! oil mu/ be ?or\ghly & con/antly di/ribut$ to ea*4 ,( c\rse1 _m small] motors1 provid$ ) b a s+le cam %aft & a ?ree-be>+ crank %aft1 may possess b "o-half ( ?is numb] ( lubricat$ p>ts1 b at ! lea/1 ! oil mu/ rea* ) unfail+ c]ta9ty two doz5 vital places ( ! eng9e4 ,at "s ( ^! portions1 ! movem5t is comp>atively sl[ & ! pressure is n great4 ,!re=e su* surfaces z ! cams or valve /em roll]s w dem& less oil ?an w ! be>+s revolv+ at high] spe$ & c>ry+ heavi] loads4 ,b x is ! h>de/-work$ be>+s t =m ! majority ( ! friction surfaces ( a motor1 z w be realiz$ :5 x is rememb]$ t all po9ts on ! circumf]5ce ( a ?ree-in* crank %aft be>+ w travel at ! approximate rate ( #a1jjj feet p] m9ute--& ^! are ! portions t also c>ry ! heavie/ load4 ,b :ile ! pi/ons c h>dly be call$ be>+s 9 ! g5]ally-accept$ layman's def9ition ( ! t]m1 !y require ! lion's %>e ( ! lubricant1 & are ! fir/ portions ( ! motor to feel--& %[--! effect ( any failure ( ! oil+ sy/em4 ,:ile 9 t]ms ( miles p] h\r1 ! movem5t ( ! pi/ons may n seem v rapid1 ! ?\s& feet p] m9ute at :i* ea* ord9>ily travels is r a high rate ( spe$ :5 x is consid]$ t x is entirely a rubb+ or a slid+ motion1 & t ! direction is rev]s$ m ?an two ?\s& times dur+ ea* sixty-second p]iod4 ,?is means t ea* pi/on slides or rubs )9 ! cyl9d] walls = a di/ance ( betwe5 two & ?ree ?\s& miles dur+ an ord9>y season4 ,& rememb] t ?is is n a roll+ motion1 b a cont9u\s rubb+6 ,9 addition to ?is high-spe$ rubb+1 ! pi/ons are press$ firmly aga9/ ! side ( ! cyl9d]s on ea* explosion /roke ?r\gh\t a portion ( _! travel4 ,?is corresponds to a heavy pressure c>ri$ by ! rubb+ surfaces1 & is caus$ by ! side ?ru/ induc$ by ! angul>ity ( ! connect+ rod z x ov]comes ! resi/ance ( ! load ?r\gh ! crank %aft4 ,b ?is is only a small portion ( ! difficulties t mu/ be ov]come 9 cyl9d] lubrication4 ,n only mu/ ! oil pacify ! rubb+ surfaces & keep !m well sep>at$1 b x mu/ rema9 )9 a re/rict$ t]ritory ( ! cyl9d] walls4 ,:atev] oil rea*es ! upp] portion ( ! cyl9d] walls w be burn$ & w contribute to ! =mation ( ! c>bon t is ! mortal enemy ( effici5t runn+4 ,l>ge quantities ( oil burn$ 9 ! cyl9d] w also =m ! d5se cl\ds ( *ok+ blue smoke t ! heal? au?orities ( _m cities h be5 inve/igat+1 :i* h l$ to ! enactm5t ( city ord9ances mak+ ! driv+ ( a smok+ automobile a misdemeanor4 ,9 view ( ! difficulty :i* has be5 exp]i5c$ by _m driv]s 9 suffici5tly lubricat+ ! pi/ons )\t caus+ ! c> to emit cl\ds ( smoke1 x may well be ask$1 ,:y _c an unburnable oil be us$ & !reby elim9ate ?is tr\ble8 ,?is is out ( ! "q1 = ! m9]al oils n[ us$ are obta9$ f petroleum & are c\s9s ( k]os5e1 gasol9e1 b5z9e1 & _m ( ! o!r highly-inflammable liquids t ne$ b ! t\* ( a mat* to burn almo/ ) ! rapidity ( an explosion4 ,b not)/&+ ! excitable family to :i* ! m9]al oils belong1 ! mod]n motor c> lubricants are remov$ a suffici5t di/ance f _! m inflammable relatives to enable !m to )/& a temp]ature ( betwe5 #djj & #ejj degrees1 ,fahr5heit4 ,?is is suffici5t heat-resi/+ ability to enable ! oil to /ay on ! cyl9d] walls ne> ! bottom ( ! /roke1 :]e x is mo/ ne$$2 b ev5 ?\gh its burn+ po9t c\ld be rais$ to a degree d\ble its pres5t am\nt1 x c\ld n )/& ! high temp]ature g5]at$ 9 ! top ( ! cyl9d] at ! "t ( ! explosion4 ,! temp]ature "h rea*es a po9t well above ! #bjjj-;degree m>k1 & 7 x n = ! cool+ sy/em1 p>ts ( ! int]ior ( ! cyl9d] w\ld probably be melt$ by ! cont9u$ application ( ?is excessive heat4 ,any oil1 consequ5tly1 w\ld f9d b small opportunity to rema9 9 its normal /ate aft] x once rea*$ a po9t at :i* x w\ld be expos$ to ! heat ( ! explosions1 & we mu/ look = a prev5tive measure o!r ?an t ( increas+ ! fla%-po9t or burn+-po9t ( ! lubricant4 ,b ?is high temp]ature does n exi/ ?r\gh\t ! /roke1 = z ! pi/on desc5ds & ! gas exp&s1 heat is giv5 (f until ! oil on ! l[] portions ( ! cyl9d] uncov]$ by ! pi/on is sometimes able to rema9 9 comp>ative peace4 ,& ev5 ?\gh ?is oil rema9+ on ! cyl9d] walls at ! bottom ( ! /roke %\ld be burn$1 x w\ld n be pres5t 9 suffici5t volume to create ! d5se cl\ds ( objectionable smoke4 ,consequ5tly x is ! endeavor ( eng9e]s s to design ! pi/ons & lubricat+ sy/em t excess oil w n be f$ to ! pi/ons & all[$ to rema9 on ! walls aft] ! =m] h desc5d$4 ,b an excess am\nt ( oil f$ to ! cyl9d]s w result 9 s mu* less h>m ?an w an insuffici5t supply1 t we are tread+ on r dang]\s gr\nd :5 we w>n ! amateur to cut d[n 8 lubricant to ! po9t :]e !re w be no smoke4 ,z !re are no ord9ances t absolutely prohibit ! slighte/ appe>ance ( smoke at ! exhau/1 & z a fa9t blue trail is an excell5t indication t ! motor is receiv+ suffici5t lubrication 9 ! cyl9d]s1 x =ms a satisfactory te/ by :i* ! novice c det]m9e ! condition ( ! oil+ sy/em4 ,by ! "t t ! exhau/ gases h pass$ ?r\gh ! pipes & h exp&$ 9 ! muffl]1 "s ( ! blue smoke may h disappe>$1 & consequ5tly ! fact t a c> does n give a trace ( vapor at its exhau/ %\ld n necess>ily be tak5 z an indication t ! motor is n well lubricat$4 ,if ! own] w\ld satisfy himself t ! cyl9d]s are receiv+ a suffici5t am\nt ( oil1 he may op5 ! individual pet cock on ea*1 & if he f9ds !re a fa9t blue trail ( smoke at ea* explosion 9 t cyl9d]1 he may re/ assur$ t h>mony exi/s betwe5 ! rubb+ surfaces ( ! pi/on & ! cyl9d] walls4 ,) ! increase 9 ! size & p[] ( ! automobile motors & ! proportionately great] numb] ( p>ts dem&+ lubrication1 ! att5tion requir$ f ! driv] by ! oil+ sy/em has be5 greatly less5$4 ,in/ead ( ! necessity ( turn+ on individual oil cups :5ev] ! motor is />t$1 ! mod]n driv] m]ely twirls ! />t+ crank or presses ! button ( ! self-/>t]1 secure 9 ! k t :5ev] ! motor runs1 ! lubricat+ sy/em op]ates--provid$1 ( c\rse1 ! res]voir is fill$ & !re is no /oppage 9 ! pipes4 ,! oil+ sy/em ( ! mod]n motor is absolutely automatic1 & if suppli$ ) a suffici5t quantity ( a good lubricant1 x w p]=m its "w ) an abs5ce ( tr\ble t places x among ! greate/ improvem5ts ( ! eng9e ( rec5t ye>s4 ,individual oil cups su* z 7 us$ =m]ly1 h be5 elim9at$ f ! cyl9d]s1 & :atev] sight-fe$s !re may be are plac$ on ! da% 9 pla9 view ( ! driv]4 ,in/ead ( rely+ ^u ! suction ( ! cyl9d]s = ! positive fe$ to ! pi/on1 me*anically-op]at$ pumps are us$ to =ce ! oil to ! v>i\s portions ( ! motor4 ,9 "s sy/ems1 !re is a sep>ate pump = ea* oil lead4 ,?is is kn[n z a me*anical oil]1 & g5]ally consi/s ( an oil tank locat$ on ! da%bo>d ( ! c>--ei!r 9 front ( ! driv]1 or "u ! motor hood--& connect$ by means ( a belt or ge> ) "s %aft ( ! motor4 ,! belt or ge> drives a %aft to :i* is connect$ ! plung]s ( ! v>i\s oil pumps t =ce ! oil to ! diff]5t p>ts ( ! motor4 ,be=e pass+ to ! individual pipe1 h[ev]1 ! oil drops ?r\gh a sight-fe$ connect$ ) t lead1 & z all ( ^! sight-fe$s are m\nt$ 9 a r[ )9 pla9 view ( ! driv]1 ! condition ( ! lubricat+ sy/em 9 "p or 9 :ole may be det]m9$ at a glance4 ,! p>ts ( ! motor t are lubricat$ by an indep5d5t fe$ l9e 9 ?is mann] may v>y ) diff]5t motors4 ,9 g5]al1 h[ev]1 x may be said t x is seldom t ! oil is f$ directly to ! pi/on1 b t ! lubricant is fir/ di/ribut$ to ! oil wells 9 ! crank case4 ,"h1 ! spla% ( ! cranks z !y revolve 9 ! oil is dep5d$ ^u to ?r[ ! lubricant ^u ! expos$ portion ( ! pi/on z x reciprocates bel[ ! cyl9d] walls4 ,! sides ( ! pi/on ?us cov]$ c>ry ! oil to ! cyl9d] walls4 ,x is evid5t t if an excess am\nt ( oil is cont9ually c>ri$ up by ! pi/on to ! cyl9d] walls1 a c]ta9 proportion ( ?is lubricant w rea* ! op5 space 9 :i* ! *>ge is ignit$1 & w !re be burn$--) ! att5dant =mation ( cl\ds ( objectionable smoke4 ,?is tr\ble is ov]come to a c]ta9 ext5t 9 "s motors by ! use ( a type ( r+ set 9 ! pi/on t prev5ts ! lubricant f pass+ to ! upp] portion ( ! cyl9d]2 b all ! oil _c ?us be reta9$1 & x !re=e behooves ! driv] n to all[ too great a quantity to be f$ to ! crank case if ! spla% sy/em is us$4 ,! ma9 be>+s on :i* ! crank %aft revolves are g5]ally suppli$ ) oil by indep5d5t leads f ! oil]1 & :5 ! above-describ$ sy/em is us$ !y may be regulat$ indep5d5tly ( ! spla% fe$ lubricat+ pipes4 ,excess oil at ! be>+s w cause no damage1 b ea* crank %aft j\rnal does n dem& z great an am\nt z t suppli$ to a pi/on & connect+ rod be>+4 ,_m lubricat+ sy/ems t are n[ 9 popul> use employ b "o pump to =ce ! oil to ! v>i\s be>+s & rubb+ surfaces1 & regulate ! supply by ! size ( ! pipe lead+ to ea*4 ,a satisfactory me?od ( ov]com+ ! possibility ( excess oil 9 ! cyl9d] has be5 adopt$ by "s manufactur]s4 ,?is consi/s 9 plac+ a *annel1 or tr\gh1 directly "u ! l[] sweep ( ea* connect+ rod be>+4 ,ea* *annel is kept fill$ to ov]fl[+ by a sep>ate pipe connect$ ) ! ma9 lead f ! pump1 & a con/ant level is consequ5tly ma9ta9$ at all spe$s ( ! motor4 ,an elaboration ( ?is me?od consi/s 9 atta*+ "o end ( ea* tr\gh to a rod op]at$ 9 conjunction ) ! ?rottle1 s t z ! spe$ ( ! motor increases1 ! end ( ! *annels may be tilt$1 ) ! result t ! connect+ rod scoop w dip deep] into ! lubricant4 ,aft] ! prop] level 9 ea* tr\gh has be5 rea*$ ! excess oil ov]fl[s into ! bottom ( ! crank case4 ,f "h1 x is aga9 />t$ on its way by ! pump & is di/ribut$ to ! v>i\s be>+s & tr\ghs ?r\gh ! diff]5t pipes lead+ f ! pump4 ,z a fur!r precaution aga9/ a smok+ exhau/1 "s design]s h add$ a baffle plate above ea* crank case comp>tm5t t s]ves to r$uce ! size ( ! op5+ ?r\gh :i* ! oil may be spla%$4 ,) ?is comb9ation ( tr\ghs & baffle plates ! possibility ( a smok+ motor is practically elim9at$4 ,all motors are n s equipp$1 h[ev]1 & 9 ! case ( ^? provid$ ) ! bona-fide spla% sy/em1 c>e mu/ be tak5 to keep ! sep>ate crank case comp>tm5ts fill$ to ! prop] level4 ,too high a level 9 ! crank cases w cause ! motor to smoke2 :ile ! supply %\ld n be all[$ to become s l[ t :5 ! angle ( ! crank case is *ang$--z 9 asc5d+ a hill--! lubricant w run t[>d ! re> & w n be rea*$ by ! scoop on ! connect+ rod be>+4 ,?is latt] dang] makes x advisable to give ?is sy/em pl5ty ( oil :5 any t\r+ is to be done ?r\gh a hilly di/rict4 ,9 "s lubricat+ sy/ems1 ! oil is suppli$ z x is us$1 & ei!r is dis*>g$ ) ! exhau/1 or collects 9 ! bottom ( ! crank case1 f :i* x %\ld be dra9$ occasionally4 ,9 ! circulat+ sy/ems1 h[ev]1 :i* are n[ us$ on a majority ( ! c>s1 ! same oil is us$ cont9u\sly until x becomes worn or fill$ ) s$im5t & p>ticles ( dirt & o!r =eign matt]4 ,! pump us$ = ma9ta9+ ?is circulation may be ei!r ( ! plung]1 c5trifugal1 or ge> type1 & is g5]ally h\s$ 9 a portion ( ! crank case4 ,a /ra9] is usually plac$ 9 ! suction end ( ?is pump = ! purpose ( remov+ all ! free =eign matt] f ! oil be=e x is aga9 />t$ on its mission ( lubrication4 ,9 ^! sy/ems1 ! oil well is g5]ally locat$ 9 a second>y bottom ( ! crank case4 ,f "h x may be dra9$ :5 ! supply is to be r5ew$4 ,ano!r successful sy/em by :i* all ! be>+s ( ! crank %aft are positively lubricat$ is us$ on _m ( ! be/ c>s4 ,9 ?is sy/em1 a cont9u\s oil hole passes ?r\gh\t ! l5g? ( ! crank %aft1 includ+ its arms & connect+ rod be>+s4 ,at ea* be>+1 "o or two small oil holes connect ) ?is ma9 art]y & ext5d radially to ! surface4 ,oil is =c$ into ! longitud9al oil hole by means ( a small pump1 & naturally f9ds its way ?r\gh e radial op5+ to all ! be>+s4 ,! excess may ov]fl[ into ! individual oil wells1 f :i* x w be spla%$ ^u ! expos$ portions ( ! pi/ons z !y desc5d4 ,x w be se5 t1 no matt] :at mod]n oil+ sy/em is us$1 ! same k9d ( lubricant is suppli$ to all p>ts ( ! motor4 ,?is feature makes matt]s mu* simpl] ?an 0 ! case :5 "o oil 0 us$ = ! cyl9d]s1 ano!r1 ( a diff]5t ?ickness1 suppli$ to ! crank case1 & /ill a ?ird requir$ = ! ge>s4 ,by ! old gravity sy/ems1 ! fl[ ( oil dep5d$ l>gely ^u its viscosity1 or ?ickness4 ,!re=e1 9 w9t]1 a ?9n] oil 0 requir$ ?an 9 summ]1 = ! m a lubricant is w>m$1 ! ?9n] does x become--& vice v]sa4 ,) ! me*anical =ce sy/ems n[ 9 use1 h[ev]1 practically ! same k9d ( oil may be us$ ?r\gh\t ! ye>--al?\gh _m motori/s believe t bett] results w be obta9$ if a heavi] oil is us$ 9 summ] ?an 9 w9t]4 ,! oil w be w>m$ by ! motor & x w n require _m m9utes ( op]ation be=e a lubricant made ?ick by a l[ temp]ature w fl[ freely & d its "w z effici5tly z a ?9n] oil4 ,b no matt] h[ reliable a lubricat+ sy/em may be 9 its op]ation1 ! driv] mu/ d 8 %>e & make c]ta9 t fre% oil ( ! prop] quality is suppli$ :5 ne$$1 & assure himself t all ! passages are free f ob/ructions4 ,neglig5ce on ! driv]'s "p may result 9 "o or m /uck pi/ons t w ei!r s]i\sly injure ! motor1 or w put x out ( commission until ! tr\ble c be rem$i$4 ,if a suffici5t supply ( oil is n f$ to ! rubb+ surfaces betwe5 ! pi/on & ! cyl9d] walls1 a high degree ( heat is g5]at$ :i* w t5d to exp& ! pi/on until x grips ! cyl9d] s closely t ! =m] _c be mov$4 ,9 ?is ev5t ! motor w /op dead1 & _c be />t$ aga9 until ! pi/on has cool$ & contract$ to its normal size4 ,ev5 !n1 h[ev]1 ! motor %\ld n be run "u its own p[] until ! burn$ & gumm$ oil has be5 remov$ & ! scor$ surfaces h be5 clean$4 ,:ile ?is may be/ be done by remov+ ! pi/on--at :i* "t an exam9ation = any badly burn$ r+s may be made--?is is n always possible1 & x may be necess>y to run ! c> home or to ! ne>e/ repair %op be=e ! prop] repairs c be made4 ,9 ?is case1 ! motor %\ld be turn$ by h& until x is c]ta9 t ! pi/on is aga9 free 9 its cyl9d]4 ,lib]al quantities ( k]os5e oil %\ld be p\r$ 9 ?r\gh ! sp>k plug op5+1 & if possible1 ! motor %\ld be rock$ back & =? by ! fly:eel to give ! k]os5e an opportunity to rea* all p>ts ( ! pi/on & r+s4 ,! k]os5e w s]ve to cut & remove mu* ( ! c>bon & gumm$ oil & to make ! way free = ! fre% lubricant1 :i* %\ld be p\r$ 9 lib]al quantities into ! cyl9d] head4 ,! fly:eel %\ld aga9 be mov$ back & =? s t ! oil w rea* all p>ts ( ! pi/on surface1 & aft] ?is--if ! damage has n be5 too great--! motor %\ld be ready = op]ation4 ,,*apt] ,,viii ,,cool+ ,to enable ! p>ts ( a motor to "w well1 !re mu/ be fre$om ( motion betwe5 all t move 9 contact ) ea* o!r4 ,?is necess>y fre$om ( motion is provid$ = to a c]ta9 ext5t by prop] lubrication1 b ?is is n all-suffici5t4 ,! necessity = "s additional friction- & heat-r$uc+ sy/em c be bett] realiz$ :5 x is und]/ood t ! temp]ature ( ! explosion 9 ! cyl9d]s ( a gasol9e eng9e is well ov] #b1fjj degrees1 ,fahr5heit4 ,! melt+ po9t ( pure iron is less ?an #b1hjj degrees4 ,!re=e 7 !re no escape = ?is heat1 & c\ld ! motor be induc$ to run "u ^! sev]e conditions1 ! cyl9d]s w\ld soon rea* a temp]ature dang]\sly ne> ! melt+ po9t4 ,long be=e ?is po9t c\ld be rea*$1 h[ev]1 ! int5se heat w\ld h exp&$ ! pi/ons s t !y w\ld become /uck 9 _! cyl9d]s1 & no m explosions c\ld occur4 ,an om9\s knock 9 "o or m ( ! cyl9d]s1 foll[$ by a sudd5 labor+ & f9al cessation ( op]ation on ! "p ( ! motor1 is sometimes ! fir/ intimation t ! driv] may h t 8 eng9e is ov]-heat$2 b s]i\s z a /uck pi/on may seem1 x is =tunate t ! motor /ops ( its own accord1 = to cont9ue to run "u ^! conditions ( con/antly increas+ heat w\ld be to wreak f> m s]i\s & p]man5t damage ^u ! mov+ p>ts ?an ! brok5 r+s or scor$ cyl9d]s t usually result f a lack ( lubrication or cool+ m$ium4 ,a l>ge am\nt ( ! heat result+ f ea* explosion is c>ri$ out ?r\gh ! exhau/ pipe 9 ! =m ( ! burn$ gases1 :ile o!r portions radiate into ! surr\nd+ air4 ,^! outlets are n suffici5t1 h[ev]1 to c>ry away all ! heat t is necess>y to enable ! motor to run effici5tly1 = prop] pi/on lubrication is exce$+ly difficult to obta9 at high temp]atures4 ,!re mu/1 !re=e1 be m positive & direct means = c>ry+ (f ?is undesir$ heat1 & to accompli% ?is result e int]nal combu/ion motor is provid$ ) a cool+ sy/em ( ei!r ! air or liquid 7usually wat]7 type4 ,motorcycle p[] plants & a few ( ! small & m$ium-siz$ automobile eng9es employ ! air-cool+ sy/em2 ! great majority ( automobile eng9es1 /ation>y plants1 & m>9e motors use wat] z ! cool+ m$ium4 ,let u consid] fir/ ! air-cool$ sy/em4 ,! area pres5t$ by ! outside ( a smoo? cyl9d] is n l>ge en\gh to enable suffici5t radiation to take place4 ,t is1 ! heat is conc5trat$ on a comp>atively small surface1 & ?is is mu* m difficult to keep cool ?an is ! same am\nt ( heat di/ribut$ ov] a great] area--= ! cyl9d] w be expos$ to a l>g] quantity ( fre% air 9 ! latt] case4 ,!re=e _m air-cool$ eng9es are provid$ ) a s]ies ( grooves & flanges on ! out] surface ( ! cyl9d]4 ,! heat is conduct$ to all p>ts ( ?is surface--flanges z well z grooves--& ! area ( ! surface t is expos$ to ! cool+ air is greatly increas$ !reby4 ,^! grooves & flanges may ext5d circumf]5tially ar\nd ! cyl9d]1 z is ! case ) _m motorcycle eng9es1 or !y may ext5d longitud9ally4 ,ano!r =m ( air-cool+ sy/em consi/s ( p9s or sp9es project+ radially f ! surface ( ! cyl9d]4 ,! motion ( ! c> ?r\gh ! air is g5]ally suffici5t to create a circulation ( ! cool+ m$ium1 b 9 ord] t ?is circulation may cont9ue :ile ! c> is at re/ a high-spe$ fan is provid$ t draws ! air f ! front t[>d ! re> ( ! motor4 ,?is s]ves also to supplem5t ! air circulation produc$ by ! motion ( ! c>1 & keeps ! motor mu* cool] ?an w\ld be ! case 7 ! ma*9e run )\t ! fan4 ,?is fan is g5]ally atta*$ to a bracket at ! front ( ! motor1 & is driv5 ei!r by a belt or ge>$ %aft4 ,9 "s designs1 h[ev]1 ! fan blades are includ$ 9 ! fly:eel at ! re> ( ! motor & ! air is ?us suck$ ov] ! cyl9d]s4 ,"o ( ! mo/ effective air-cool+ sy/ems = use on an automobile motor consi/s ( ! above-m5tion$ longitud9al flanges & grooves enclos$ 9 a ?9 jacket or cas+ surr\nd+ ea* cyl9d]4 ,^! jackets are op5 at ! top & bottom ( ! cyl9d]s1 & connect ) l>ge pipes1 or tr\ghs1 ?r\gh :i* air is =c$4 ,! tr\gh into :i* ! top ( ! jacket spaces op5 is connect$ ) ! dis*>ge end ( a l>ge fan4 ,! air is ?us driv5 into ! top tr\gh1 ?r\gh ea* jacket1 & into ! l[] tr\gh1 ! f>!r t]m9ation ( :i* is connect$ ) ! suction end ( a fan includ$ 9 ! fly:eel4 ,! two fans s]ve to set up a rapid circulation ( air :i*1 by means ( ! tr\ghs & jackets1 is conc5trat$ ^u ! surfaces ( ! grooves & flanges ( ea* cyl9d] & none is wa/$ on p>ts ( ! motor t x is unnecess>y to cool4 ,fur!rmore1 ! re> cyl9d]s receive z mu* air z d ! =w>d ones1 = ! tr\gh s]ves to di/ribute ! circulation equally along ! grooves & flanges ( ea*4 ,inasmu* z ! heat f an air-cool$ motor is radiat$ directly into ! curr5t ( air itself1 ! surface is v susceptible to temp]ature *anges f ! int]ior4 ,?us1 if ! c> is run = a great di/ance on ! l[ ge>1 & ! cyl9d]s become hot 9 consequ5ce1 a l>g] am\nt ( heat w imm$iately be radiat$ f ! cool+ surfaces ?an is ! case :5 ! motor is runn+ sl[ly4 ,a coa/ d[n a %ort hill1 h[ev]1 w s]ve to cool ! motor rapidly1 = if ! eng9e is run f ! mom5tum ( ! c> ) ! sp>k turn$ (f1 cool air w be drawn into ! cyl9d]s1 & ?is1 9 addition to ! circulation ( cold air on ! outside1 w r$uce ! temp]ature ( ! eng9e rapidly4 ,?is is a feature ( ! op]ation ( an air-cool$ motor t is n possess$ to s l>ge an ext5t by ^? ( ! wat]-cool$ type4 ,x is1 p]haps1 h>dly accurate to apply ! t]m wat]-cool$ to ! ord9>y type ( automobile motor4 ,wat] is m]ely ! m$ium t transf]s ! heat f ! cyl9d]s to ! cool+ surface ( ! radiator4 ,z air is us$ to cool ?is heat$ wat]1 we see t ! only diff]5ce betwe5 ! two sy/ems lies 9 ! po9t ( application ( ! actual heat-absorb+ m$ium--:i* is air 9 bo? cases4 ,?us 9 ! air-cool$ motor ! air is c>ri$ directly to ! surfaces to be cool$2 :ile 9 ! o!r type1 ! heat is transf]r$ by means ( ! wat] to ! po9t :]e x may be effectually dis*>g$ into ! air4 ,ea* cyl9d] ( a wat]-cool$ motor is surr\nd$ by a space kn[n z ! wat] jacket4 ,?is space is g5]ally ca/ ) ! cyl9d]1 al?\gh 9 "s designs ( motors ! jackets are =m$ by ! subsequ5t application ( a copp] cas+ t s]ves to reta9 ! wat]4 ,! wat] jackets are connect$ ) ea* o!r by means ( pip+ & wat]-tight jo9ts s t ! wat] w pass successively f "o to ! o!r4 ,if ! wat] rema9$ 9 ^! spaces1 x w\ld soon be w>m$ to a temp]ature f> above ! boil+ po9t1 /eam w\ld be =m$1 a high pressure g5]at$1 & inf9ite h>m w\ld result--bo? to motor & to pass5g]s4 ,! pip+1 h[ev]1 does n end ) ! connections betwe5 ! cyl9d]s1 b ext5ds to & f ! radiator4 ,?is radiator is a l>ge1 p]=at$ /ructure plac$ ei!r =w>d ( ! motor to =m ! end ( ! bonnet-cov]+1 or 9 front ( ! da% betwe5 x & ! re> cyl9d] ( ! eng9e4 ,! radiator is a mass ( small cellul> or tubul> passages1 ea* "o ( :i* possesses an exce$+ly l>ge out] surface 9 proportion to ! am\nt ( wat] t x c conta94 ,:5 ! hot wat] rea*es ! radiator x is di/ribut$ to ^! _m cells or tubes1 & is ?us spread ov] a l>ge cool+ surface4 ,a l>ge fan is usually locat$ directly beh9d ! radiator1 & z ?is s]ves to draw ! air rapidly ?r\gh ! op5+s betwe5 ! cells or tubes1 cool+ is greatly facilitat$4 ,!re are sev]al types ( radiators 9 g5]al use4 ,"s consi/ ( a numb] ( flat cells plac$ 9 su* a mann] t regul>-%ap$ air op5+s w be =m$4 ,ea* side ( ea* flat wat] cell abuts on an air passage4 ,su* a radiator is kn[n z ! honeycomb1 or cellul>1 ! =m] t]m be+ appli$ to ^? ^: cells resemble a honeycomb4 ,! tubul> radiator consi/s ( a numb] ( v]tical1 p>allel tubes ?r\gh :i* ! wat] passes1 & :i* are plac$ a suffici5t di/ance ap>t to provide ample air passages betwe5 !m4 ,ea* tube is cov]$ at frequ5t int]vals ) flut$1 circul> flanges t s]ve to increase ! radiat+ surface 9 mu* ! same mann] z d ! grooves & flanges on ! cyl9d]s ( ! air-cool$ motor4 ,all air passages 9 any radiator ext5d directly ?r\gh ! wid? ( ! radiator1 :ile ! wat] circulates f top to bottom 9 a v]tical direction4 ,! reason = ?is circulation ( ! wat] w be app>5t if we call to m9d a bit ( our elem5t>y physics4 ,:5 wat] is heat$1 x exp&s & rises1 & = ?is reason1 we always f9d ! surface ( ! wat] 9 a teakettle w>m] ?an is t at ! bottom--al?\gh ! latt] is clos] to ! fire4 ,z ! wat] is circulat$ ?r\gh ! radiator1 x is cool$ by ! passage ( ! l>ge am\nt ( air ?r\gh ! op5+s betwe5 ! cells or tubes4 ,! wat] ?us cool$ s9ks to ! bottom ( ! radiator & is replac$ by ! wat] j heat$ by ! motor4 ,! cool$ wat] is conduct$ to ! bottom portion ( ! end cyl9d]1 & passes to ! o!rs 9 succession1 gradually ris+ z x is heat$1 until x is aga9 =c$ to ! radiator at ! top4 ,!re are two me?ods ( circulat+ ! wat] ?r\gh ! cyl9d] jackets & radiator4 ,! mo/ common me?od consi/s ( ! introduction ( a pump 9 ! l[] portion ( ! circulat+ sy/em4 ,9 ! case ( automobile motors1 ?is pump is driv5 by ge>s connect$ ) ! crank %aft ( ! eng9e4 ,su* a pump w be ei!r ( ! ge> or c5trifugal type1 & w suck ! cool$ wat] f ! l[] portion ( ! radiator1 & =ce x ?r\gh ! jackets4 ,! second me?od is kn[n z ! !rmo-syphon sy/em because ! circulation is automatic & dep5ds ^u ! cool+ ( ! wat] 9 ! radiator4 ,:5 ! cool$ wat] s9ks1 a syphon action is =m$ t t5ds to draw ! hot wat] f ! cyl9d] jackets1 & ! automatic circulation w ?us cont9ue z long z ! successive heat+ & cool+ take place4 ,inasmu* z ! pump is driv5 by ! crank %aft ( ! eng9e1 its spe$ w be proportional to t ( ! motor4 ,! same holds true ( ! fan t s]ves to draw ! air ?r\gh ! radiator4 ,x w ?us be se5 t bo? ! wat] & ! air are =c$ at a m rapid rate :5 ! motor runs at high spe$1 & t !re=e ! extra heat g5]at$ by ! m frequ5t explosions 9 ! cyl9d]s w be c\nt]act$ to a c]ta9 ext5t4 ,! increas$ numb] ( explosions & ! high] spe$ at :i* ! fan turns also cause quick] heat+ & cool+ ( ! wat] by ! !rmo-syphon sy/em1 ?us =m+ a m rapid circulation4 ,inasmu* z ! =ce ex]t$ ^u ! wat] by its cool+ & heat+ is n z great z t =m$ by a high-spe$ & effici5t pump1 ! pipes & connections ( ! !rmo-syphon sy/em mu/ be ( ample size 9 ord] to keep ! resi/ance to ! passage ( ! wat] z l[ z possible4 ,c>e mu/ also be tak5 9 ! design ( ?is sy/em s to con/ruct & connect ! pipes & jackets t ! hot wat] w be all[$ to rise & ! cool to desc5d1 & ?us to make possible ! syphon conditions on :i* pr9ciple ! circulation is bas$4 ,! ability ( ! radiator to c>ry (f ! heat f ! wat] dep5ds ^u ! rapidity ) :i* ! air passes ?r\gh ! passages provid$ = ! purpose4 ,! am\nt ( air pass+ ?r\gh is det]m9$ by ! spe$ ( ! suction fan & ! rapidity ( travel ( ! c> itself aga9/ ! w9d4 ,x has be5 %[n t1 :5 ! motor runs at a high numb] ( revolutions1 ! fan turns fa/] & ! rapidity ( circulation is increas$4 ,b if ! c> itself does n increase its spe$ 9 proportion to ! high] revolutions ( ! motor1 ! maximum am\nt ( air w n be =c$ ?r\gh ! radiator passages1 & ! excess heat w n be c>ri$ (f entirely f ! cyl9d]s4 ,?is is a condition t prevails :5 ! motor is run on l[ ge>4 ,! spe$ ( ! motor is increas$1 :ile t ( ! c> is r$uc$2 additional heat is g5]at$ 9 ! cyl9d]s1 b ! spe$ ( ! air is n increas$ 9 proportion4 ,!re=e a motor t is driv5 a long di/ance on ! l[ ge> w h a t5d5cy to ov]heat4 ,wat] "u atmosph]ic pressure _c be br\ght to a temp]ature above #bab degrees ,fahr5heit )\t be+ conv]t$ into /eam4 ,!re=e1 :5 ! heat f a wat]-cool$ motor _c be c>ri$ away suffici5tly fa/1 ! wat] 9 ! circulat+ sy/em w beg9 to boil4 ,z long z wat] rema9s 9 ! jackets1 ! temp]ature ( ^! spaces _c well rise above #bab degrees1 & consequ5tly !re is small dang] t a wat]-cool$ motor w become ov]heat$ to ! po9t at :i* ! pi/ons w seize 9 ! cyl9d]s4 ,! mom5t ! wat] 9 ! circulat+ sy/em beg9s to boil1 h[ev]1 exce$+ly rapid evaporation naturally takes place1 & ! wat] w soon entirely disappe> 9 ! =m ( /eam & vapor4 ,to run ! motor "u ^! conditions w mean t pi/ons & r+s w soon become /uck 9 _! cyl9d]s1 al?\gh lib]al quantities ( oil w sometimes delay ?is inevitable result4 ,b ev5 :5 ! cool+ wat] is n br\ght to ! boil+ po9t !re is a vapor t is con/antly dispell$ f x :5ev] its temp]ature is br\ght above t ( ! air4 ,! wat] sy/em ( an automobile mu/ !re=e be repl5i%$ at irregul> int]vals1 dep5d+ ^u ! am\nt & nature ( ! runn+ to :i* ! c> has be5 subject$4 ,! old] c>s 7 provid$ ) an extra wat] tank1 g5]ally locat$ "u ! seat1 & connect$ directly ) ! wat] jackets & ! radiator4 ,! usual wat]-cool+ sy/em ( ! pres5t-day c>1 h[ev]1 is self-conta9$--t is1 !re is no sep>ate tank = ! /orage ( ! wat]4 ,! wat] is p\r$ into ! top ( ! radiator1 & f ?is high po9t x rea*es e "p ( ! circulat+ sy/em4 ,:5ev] ! radiator w accommodate a c\ple ( qu>ts1 or m1 x is well to fill x1 = too mu* wat] _c be us$ on ! mod]n design ( cool+ sy/em4 ,x is true t a motor runs at its highe/ effici5cy :5 its temp]ature is z great z t at :i* prop] lubrication ( ! pi/ons c be obta9$--= a gasol9e eng9e is a heat eng9e1 & ! great] its unnecess>y heat losses1 ! less w be ! p[] develop$ by x4 ,b a motor _c be kept at ! prop] temp]ature by r$uc+ ! am\nt ( cool+ wat] 9 its circulat+ sy/em4 ,! be/ me?od is to less5 ! rapidity ) :i* ! wat] is cool$1 & ?is may be accompli%$ by plac+ a lea!r flap1 a c>dbo>d1 or o!r ob/ruction ov] a portion ( ! radiator to r$uce ! numb] ( op5+s ?r\gh :i* ! air may pass4 ,x %\ld only be necess>y to d ?is 9 ! colde/ wea!r1 h[ev]1 = ! cool+ sy/em ( e motor is design$ to ma9ta9 ! prop] temp]ature on all except ! hotte/ or colde/ days4 ,x has be5 /at$ 9 a prec$+ p>agraph t cont9u$ runn+ on ! l[ ge> is ! mo/ frequ5t cause ( ov]heat+ a motor4 ,?is is true1 b x is n ! only cause4 ,ob/ructions 9 ! circulat+ sy/em t r$uce ! fl[ ( wat] w h ?is effect1 z w also deposits on ! int]ior ( ! cyl9d]s t s]ve to prev5t ! prop] transf] ( heat to ! wat] 9 ! jacket spaces4 ,removal ( ! c>bon w rem$y ! latt] tr\ble1 b to cle> out ! circulat+ sy/em is m or less ( a complicat$ matt]4 ,/oppage 9 ! pipes or radiator cells may be caus$ by a lime deposit f h>d wat] t may h be5 us$ 9 ! circulat+ sy/em4 ,!re are prep>ations int5d$ to remove ?is deposit1 b su* %\ld n be us$ )\t fir/ advis+ ) ! mak] ( ! c> or an exp]i5c$ repair man4 ,a s]ies ( batt]$ cells 9 ! radiator may r$uce ! numb] ( cool+ spaces t %\ld be trav]s$ by ! wat]1 & ?us ! hot wat] _c be di/ribut$ ov] z great an air area z is necess>y to ma9ta9 ! motor at ! prop] temp]ature4 ,su* a condition w be app>5t f a m>k$ diff]5ce 9 temp]ature betwe5 ! affect$ portion ( ! radiator & ! rema9d]4 ,if a deposit has be5 =m$ on a c]ta9 s]ies ( cells1 or if !y h be5 ob/ruct$ 9 any o!r mann]1 ! hot wat] _c circulate ?r\gh ?is section ( ! radiator1 & x w rema9 comp>atively cool4 ,wat] is a liquid t rema9s 9 its fluid /age only ?r\gh a temp]ature range ( #ahj degrees--at atmosph]ic pressure4 ,at #bab degrees x boils & turns to vapor1 :ile at #cb degrees x freezes & becomes a solid4 ,9 nei!r ( ^! /ages does x =m a desirable cool+ m$ium = a gasol9e motor4 ,( ! two1 h[ev]1 its solid /age is ! m h>mful to ! motor4 ,n only w x cease to fl[ :5 x becomes ice1 b ! expansion ( ! wat] dur+ ! =mation ( ! solid is liable to bur/ its reta9]--:e!r x be ! cells ( ! radiator1 ! pump1 pipes1 or ev5 ! cyl9d] walls !mselves4 ,x is ! radiator t is ! mo/ liable to suff] f su* a cause1 h[ev]1 = ea* cell conta9s s small an am\nt ( wat] t ! liquid w be br\ght to ! freez+ po9t be=e ! l>g] volume 9 ! jacket spaces approa*es ?is temp]ature4 ,( c\rse ! wat] w be kept well above ! freez+ po9t :5 ! motor is runn+1 & x is only :5 ! ma*9e has /ood idle = sev]al h\rs t c>e mu/ be tak5 to prev5t ! =mation ( ice 9 ! circulat+ sy/em4 ,aside f keep+ ! c> 9 a w>m place :5ev] ! motor is to be at re/ m ?an two h\rs1 !re is only "o me?od ( prev5t+ ! cool+ wat] f freez+1 & t is by ! introduction ( "s *emical t l[]s ! po9t at :i* ! liquid w turn to a solid4 ,!re are sev]al +5i\s heat]s available t are atta*$ to ! circulat+ pipes & t s]ve to keep all ( ! jacket wat] w>m2 ! use ( ^! produc+ ! same conditions z ?\gh ! c> 7 kept 9 an artificially-heat$ g>age4 ,"o ( ! mo/ common liquids us$ 9 ! cool+ wat] to prev5t freez+ is alcohol4 ,if equal p>ts ( wood alcohol & wat] are us$ 9 ! cool+ sy/em1 ! result+ mixture w n freeze until x rea*es a temp]ature cold] ?an #be degrees bel[ z]o4 ,a weak] mixture--"o hav+ #be p] c5t4 ( wood alcohol--w freeze at ab\t z]o1 & x !re=e dep5ds ^u ! prevail+ cold-wea!r temp]ature z to ! prop] proportion t %\ld be us$4 ,x mu/ be rememb]$ t ! boil+ po9t ( alcohol is mu* l[] ?an is t ( wat]1 & t !re=e a mixture t w n freeze 9 exce$+ly cold wea!r is liable to boil away on ! fir/ mod]ate day on :i* ! c> is run4 ,! above-m5tion$ #ej p] c5t4 mixture ( wood alcohol & wat] w boil at #ace degrees1 :ile ! #be p] c5t4 solution w )/& a temp]ature #dj degrees high] be=e x is trans=m$ into vapor4 ,z ! l[] temp]ature w be rea*$ easily if ! motor is run = "s "t 9 comp>atively mod]ate wea!r1 x w be se5 t ! /rong] mixture %\ld be us$ only :]e w9t]s are v sev]e4 ,x mu/ also be borne 9 m9d t1 z alcohol boils m readily ?an does wat]1 x foll[s t x w evaporate m easily1 z well4 ,!re=e1 9 ord] to ma9ta9 a uni=m proportion ( wood alcohol to wat]1 ! =m] %\ld be repl5i%$ m (t5 ?an is ! latt]4 ,glyc]9e is ano!r sub/ance t is (t5 mix$ ) ! cool+ wat] to prev5t ! latt] f freez+4 ,a #ej p] c5t4 mixture ( ?is & wat] has a freez+ po9t ( ab\t z]o1 or slightly l[]1 & boils at practically ! same temp]ature z wat]--#baj degrees4 ,comb9ations ( wood alcohol & glyc]9e may be us$--equal p>ts ( ea* be+ ! usual proportion--& ?us v>i\s freez+ & boil+ po9ts may be obta9$4 ,! radiator is "o ( ! mo/ delicate p>ts ( ! motor c>'s con/ruction1 & yet x is ! mo/ expos$ to fly+ /icks & /ones t may be ?r[n up by ! rapid travel ( ! c>4 ,! c> own] may d well to foll[ ! practice ( _m rac+ driv]s :o place a heavy wire me% scre5 9 front ( ! radiator z a protection aga9/ ob/acles t may be /ruck by ! front ( ! c>4 ,x w\ld seem t /icks & /ones w\ld be ?r[n t[>d ! re> ( ! c>1 & w\ld !re=e avoid ! radiator by a wide m>g91 b exp]i5ce has prov$ t1 at high spe$1 su* loose pieces are frequ5tly =c$ =w>d & are run into by ! front ( ! c>4 ,,*apt] ,,ix ,,two-,,cycle ,,motors ,!re has always be5 a /rong prejudice 9 favor ( ! f\r-cycle motor = ! p[] plant ( ! gasol9e automobile4 ,?is may be due to ! fact t design]s h sp5t mo/ ( _! "t & en]gy on ! developm5t ( ?is eng9e1 & t !re=e ! two-cycle type has n yet be5 suffici5tly tri$ out 9 ! motor c> to enable u to judge fairly z to its real m]its4 ,c]ta9 x is t 9 ! few in/ances 9 :i* ! two-cycle motor has be5 us$ z an automobile p[] plant1 ! results h be5 highly satisfactory1 & ! pres5t vogue ( ! f\r-cycle motor--) well ov] #ih p] c5t4 ( ! automobiles n[ made adh]+ to ?is type--is l>gely due to popul> prejudice 9 its favor4 ,z has be5 describ$ 9 ! fir/ *apt] ( ! pres5t volume1 ! f\r-cycle motor devotes a sep>ate /roke to ea* ( ! ev5ts ( expansion1 scav5g+ or expulsion ( ! burn$ gases1 suction1 & compression4 ,! two-cycle motor1 on ! o!r h&1 devotes b two /rokes to ^! f\r ev5ts1 & !re is !re=e an explosion twice z (t5 9 ! two-cycle eng9e cyl9d] z is ! case ) ! f\r-cycle type4 ,b 9 lieu ( ! suction /roke ( ! f\r-cycle motor1 !re mu/ be "s me?od ( =c+ ! *>ge into ! cyl9d] ( ! two-cycle eng9e4 ,! base1 or comp>tm5t bel[ ! pi/on1 9 :i* ! crank revolves1 is us$ = ?is purpose4 ,z ! pi/on travels upw>d on its compression /roke1 a p>tial vacuum is =m$ 9 ! base1 & if a passage is op5$ betwe5 ?is comp>tm5t & ! c>buretor1 ! *>ge w be suck$ 94 ,all outside connections ) ! base are tightly clos$ on ! d[n-/roke ( ! pi/on1 & consequ5tly ! rec5tly-inhal$ *>ge w be compress$1 ready = its entrance into ! cyl9d] above ! pi/on z soon z ! connect+ passage is op5$4 ,?is passage is op5$1 z has already be5 describ$1 at ! bottom ( ! /roke & ! compress$ *>ge ru%es 9 & fills ! space 9 ! cyl9d] t at t "t is be+ vacat$ by ! exhau/ gases4 ,! majority ( two-cycle motors are made )\t any valve me*anism1 ! op5+ & clos+ ( ! passages be+ entirely automatic4 ,^! passages are ca/ ) ! eng9e & lead into ! cyl9d] ?r\gh op5+s 9 ! walls call$ ports4 ,! op5+ lead+ f ! cyl9d] to ! exhau/ pipe1 or exhau/ port1 is plac$ ne> ! bottom ( ! /roke s t x is cov]$ by ! pi/on1 except at ! l[] extremity ( ! travel ( ! latt]4 ,j bel[ ! exhau/ port1 & on ! opposite side ( ! int]ior ( ! cyl9d]1 is plac$ ! intake port1 or op5+ ( ! passage connect+ ! cyl9d] ) ! base4 ,n[1 z ! pi/on is =c$ d[nw>d1 x uncov]s ! exhau/ port & an easy means ( escape is furni%$ = ! burn$ gases4 ,imm$iately aft] ?is1 ! intake port on ! opposite side is uncov]$ by ! /ill-desc5d+ pi/on1 & ! previ\sly compress$ *>ge1 :i* is only await+ ! opportunity 9 ! base1 bl[s 94 ,! exhau/ gases are /ill escap+ :5 ?is happ5s1 & !re=e x is necess>y to prev5t ! incom+ *>ge f pass+ directly across ! top ( ! pi/on & out ?r\gh ! exhau/ port be=e use has be5 made ( its explosive qualities4 ,consequ5tly1 to keep x 9 its prop] pa?1 a baffle plate is atta*$ to ! top ( ! pi/on :i* s]ves to deflect ! incom+ *>ge t[>d ! top ( ! cyl9d]1 & ?is n only prev5ts ! loss ( ! mixture1 b also furni%es a bla/ ( air t helps to bl[ out ! burn$ gases4 ,on ! return ( ! pi/on to ! top ( its /roke1 x fir/ passes ov] ! intake port & !n cov]s ! exhau/ port1 effectually clos+ bo? & prev5t+ ! escape ( ! *>ge dur+ compression4 ,:ile ?is is go+ on1 x mu/ be rememb]$1 ! pi/on is =m+ ! p>tial vacuum 9 ! base1 :i* s]ves to draw 9 ! *>ge = ! succe$+ explosion4 ,if ! *>ge is drawn directly into ! base f ! c>buretor1 a *eck valve mu/ be us$ 9 ! pipe connect+ ! two2 o!rwise ! mixture w\ld be =c$ back into ! c>buretor ! in/ant ! pi/on began its desc5t4 ,a two-cycle motor draw+ its *>ge 9 ?is mann] is kn[n z ! two-port type1 = !re are only ! exhau/ & ! inlet ports 9 ! int]ior ( ! cyl9d] walls4 ,! passage connect+ ! c>buretor ) ! base may ent] at ! bottom ( ! cyl9d]1 = ?is space & ! base are ! same :5 ! pi/on is at ! top ( its /roke4 ,?us if ?is port is plac$ s t x is uncov]$ :5 ! pi/on is at ! top ( its /roke1 x w admit ! *>ge to ! base at a "t :5 a p>tial vacuum has be5 creat$ 9 ?is comp>tm5t by ! upw>d movem5t ( ! pi/on4 ,?is port is aga9 cov]$ z soon z ! pi/on />ts on its d[nw>d j\rney1 & ?us ! *>ge is prev5t$ f escap+ until ! intake port connect+ ! base ) ! top ( ! cyl9d] is op5$4 ,su* a two-cycle motor is kn[n z ! ?ree-port type1 & x w be se5 t n ev5 an automatic *eck valve is us$ 9 its passages--& x is consequ5tly a valveless motor 9 ! lib]al int]pretation ( ! t]m4 ,! high velocity ( ! *>ge recomp5ses = ! %ort "t t ! port is uncov]$1 & consequ5tly ! base is fill$ ) ne>ly z l>ge an am\nt ( *>ge z is ! case ) ! two-port motor--:i* all[s ! incom+ gases to ent] ! crank case dur+ ! entire upw>d /roke ( ! pi/on4 ,x w ?us be se5 t ! pi/on ( ! two-cycle motor acts z a pump 9 two ways4 ,fir/1 ! vacuum is =m$ t s]ves to draw ! *>ge into ! crank case1 or base1 ( ! motor2 & second1 ! return /roke ( ! pi/on compresses ?is rec5tly-inhal$ *>ge & makes x ready to be %ot up into ! cyl9d] z soon z ! pi/on has uncov]$ ! port t =ms ! upp] t]m9al ( ! communicat+ passage4 ,!re c1 ( c\rse1 no great] am\nt ( fre% *>ge ent] ! cyl9d] ?an is drawn into ! crank case4 ,consequ5tly1 ! am\nt to :i* ! cyl9d] w be fill$ dep5ds ^u ! vacuum =m$ & ! pressure ex]t$ ^u ! *>ge by ! succe$+ d[n-/roke ( ! pi/on4 ,x is to be suppos$ t ! pi/on r+s w be tight & t none ( ! *>ge c escape by !m1 & !re=e ! vacuum =m$ & pressure ex]t$ 9 ! crank case w dep5d entirely ^u ! displacem5t ( ! pi/on 9 its travel comp>$ ) ! total capacity ( ! crank case4 ,9 o!r words1 if ! crank case is l>ge & ! pi/on is small & travels b a %ort di/ance1 its pump action on ! entire volume w be small4 ,b if ! crank case is small & ! travel ( ! pi/on alt]nately d\bles & halves ! volume1 ! motion ( ! pi/on w cause ! pressure 9 ! crank case to v>y greatly4 ,9 a prec$+ p>agraph x has be5 describ$ 9 :at mann] ! incom+ *>ge 9 ! two-cycle motor 0 us$ to scav5ge ! cyl9d]1 or rid x ( burn$ gases1 by deflect+ ! mixture & all[+ ?is to =ce out ! rema9+ exhau/ be=e ! exhau/ port 0 clos$ by ! upw>d motion ( ! pi/on4 ,x is evid5t t ! great] ! =ce1 )9 c]ta9 limits1 ) :i* ! *>ge ent]s ! cyl9d]1 ! m p]fect w be ! scav5g+ action4 ,b !re is a limit to ! pressure t c be atta9$ by ! mixture :5 x is compress$ 9 ! crank case previ\s to its dis*>ge into ! cyl9d]4 ,?is limit is det]m9$ by ! size ( ! space requir$ = ! revolution ( ! crank & big end ( ! connect+ rod1 & by ! volume displac$ by ! motion ( ! pi/on4 ,! crank mu/ h room 9 :i* to revolve1 & ! displacem5t ( ! pi/on c only be ! area ( its top multipli$ by its l5g? ( /roke4 ,?us eight p\nds p] squ>e in* is ab\t ! usual limit ( crank case compression ) ?is type ( two-cycle motor4 ,?is may be v>i$ slightly "o way or ! o!r by ! arrangem5t ( ! ports1 b x makes slight diff]5ce :e!r ! motor is ( ! two- or ?ree-port type s f> z ?is consid]ation is conc]n$4 ,two-cycle motors h be5 design$ :i* comb9e ! pr9ciples ( action ( bo? ! two- & ?ree-port types4 ,! mo/ important dep>ture f ! g5]ally-accept$ type ( two-cycle motor1 h[ev]1 is ! design 9 :i* ! *>ge is f$ into ! cyl9d] f a *amb] t is absolutely indep5d5t ( ! crank case prop]4 ,?is may be accompli%$ 9 sev]al ways4 ,!re may be :at is t]m$ a diff]5tial pi/on 9 :i* a sep>ate plung] op]ates 9 ! int]ior ( ! holl[ trunk pi/on1 & by means ( ! prop] connection ) ! crank %aft compresses ! *>ge 9 ! *amb] ?us =m$ at ! "t x is to be =c$ into ! cyl9d]4 ,ano!r design = obta9+ intake compression indep5d5t ( ! crank case consi/s ( a coll>1 or circul> enl>gem5t at ! base ( ! pi/on4 ,?is coll> reciprocates )9 ! l[] portion ( ! pi/on 9 a *amb] :i* has be5 bor$ to ! exact size4 ,! coll> consequ5tly =ms a v>iable base = ?is comp>tm5t1 & z ! pi/on desc5ds1 ! coll> travels ) x1 ?us draw+ 9 a *>ge ( ! fre% mixture4 ,on ! upw>d /roke1 ?is mixture is compress$ by ! coll> z x r$uces ! size ( ! comp>tm5t4 ,x w be se5 t su* a motor c be design$ to compress ! *>ge to almo/ any am\nt4 ,inasmu* z ! mixture1 z m5tion$ above1 is compress$ on ! up-/roke ( ! pi/on1 x is evid5t t x _c be dis*>g$ into t p>ticul> cyl9d] at t "t--= ! mixture %\ld be deliv]$ to its cyl9d] only :5 ! pi/on is at ! bottom ( its /roke4 ,9 ! case ( a f\r-cyl9d] eng9e1 h[ev]1 "o ( ! pi/ons w\ld be 9 ! prop] position = ! entrance ( ! *>ge1 & x is into ?is cyl9d]1 t ! compress$ mixture is =c$4 ,! compression space 9 ea* cyl9d]1 !re=e1 works = its neighbor1 r ?an = itself4 ,?is int]*ange ( c\rtesies is obta9$ ?r\gh ! good (fices ( a di/ributor 9 ! =m ( a rotat+1 holl[ cyl9d] hav+ ports cut ?r\gh\t its l5g? t regi/] ) correspond+ passages lead+ to ! v>i\s cyl9d]s4 ,?is di/ributor is tim$ ) ! crank %aft ( ! motor1 & may be driv5 ei!r by a ge> or by a sil5t *a94 ,z ! mixture is compress$ 9 ! sep>ate *amb] ( "o cyl9d]1 ! passage lead+ to ! di/ributor is op5$ by ! revolution ( ! latt]1 & ! *>ge is l$ ?r\gh ?is passage1 ! di/ributor1 & !nce ?r\gh ano!r passage--also op5$ by ! di/ributor--to ! prop] cyl9d]4 ,! cyl9d]s ?us op]ate 9 pairs1 "o receiv+ its *>ge :ile ! o!r is ab\t to beg9 its explosion /roke--& vice v]sa4 ,! =ce ( ! explosion 9 a gasol9e eng9e cyl9d] is n only dep5d5t ^u ! am\nt & nature ( ! inflammable mixture admitt$1 b ^u ! =ce ) :i* x is compress$1 z well4 ,! av]age compression pressure ( a two- or f\r-cycle eng9e ( ! ord9>y type1 is f #fj to #gj p\nds p] squ>e in*4 ,inasmu* z ?is pressure1 assum+ t ! r+s & valves are tight1 is proportional to ! displacem5t ( ! pi/on /roke comp>$ ) ! volume ( ! cle>ance space1 ! am\nt ( compression is con/ant at all spe$s & loads ( ! motor4 ,%\ld x be possible to increase ?is compression at w1 x w\ld be f\nd t1 ) a w>m motor1 a pressure 9 ! neighborhood ( #ajj p\nds p] squ>e in* w\ld s]ve to g5]ate suffici5t heat to ignite ! mixture be=e ! =mation ( ! sp>k--= x is "o ( ! elem5t>y laws ( physics t a gas w become heat$ :5 compress$4 ,x is = ?is reason t ! compression pressure ( ! ord9>y automobile motor is kept 9 ! neighborhood ( #gj p\nds p] squ>e in*4 ,a me?od ( v>y+ compression pressure to meet individual load requirem5ts has be5 devis$ = "s motors1 h[ev]1 & :ile su* types are n z yet 9 g5]al use 9 automobiles1 x is probable t ! ne> future w f9d mu* advancem5t along ^! l9es4 ,"o su* two-cycle motor t has be5 design$ especially = automobile use employs a sep>ate air compressor driv5 by ! eng9e itself & us$ z ! clut* & v>iable spe$ transmission ( ! c>4 ,! am\nt ( pressure g5]at$ 9 ! compressor is dep5d5t ^u ! resi/ance (f]$ to its op]ation--or1 9 o!r words1 x increases ) additional load c>ri$ by ! motor4 ,! compression1 or compress$ air1 r1 is c>ri$ directly f ! compressor to ! cyl9d]s ( ! motor1 be+ admitt$ at ! prop] "t by a rot>y valve driv5 by ! crank %aft4 ,?us ! compression 9 ea* cyl9d] is automatically regulat$ by ! load1 & a motor ( ?is type possesses a high ov]load capacity4 ,! motor m5tion$ above op]ates on some:at ! same pr9ciples z ^? f\nd 9 ! ,diesel eng9e1 :i* w be1 z _m pr$ict1 ! ultimate type ( int]nal combu/ion motor4 ,! ,diesel motor is n necess>ily a p>ticul> make ( eng9e1 b be>s ! "n ( ! orig9ator ( ! pr9ciples involv$4 ,^! are di/9ct f ^? ( ! ,otto cycle1 :i* is ! pr9ciple ^u :i* practically all automobile motors op]ate4 ,! ,otto cycle consi/s ( ! well-kn[n s]ies ( ev5ts 9 ! cyl9d]1 z foll[s3 ,ignition1 foll[$ by ! explosion1 or expansion ( ! burn$ *>ge2 dis*>ge ( ! exhau/ gases1 or scav5g+2 admission ( ! fre% *>ge1 suction2 & compression ( ! newly-receiv$ mixture previ\s to ignition & ! repetition ( ! cycle4 ,9 speak+ ( ! ,otto & ,diesel eng9es1 x mu/ be borne 9 m9d t !y are ref]r$ to z a class1 r ?an z a p>ticul> make--z "o w\ld m5tion poppet valve or sleeve valve eng9es--= !re may be _m manufactur]s ( ea* type4 ,al?\gh ! ,diesel pr9ciple may be appli$ to ei!r ! two or f\r-cycle type ( motor1 x is to ! =m] design t x l5ds itself unusually well4 ,?is motor op]ates a two-/age air compressor 9 conjunction ) a /orage tank4 ,at ! beg9n+ ( ! compression /roke1 pure air "u high pressure is admitt$ to ! cyl9d]4 ,9 its upw>d travel1 ! pi/on compresses ?is air to a pressure approximat+ #ejj p\nds p] squ>e in*4 ,:ile x has be5 %[n t su* a pressure is ab\t five times m ?an en\gh to g5]ate suffici5t heat to cause premature ignition1 x mu/ be rememb]$ t1 unlike ! ord9>y type ( motor1 ?is is only pure air t is inject$ into ! cyl9d] & conta9s none ( ! explosive gasol9e vapor4 ,at ! top ( ! /roke1 h[ev]1 :5 ! compression is at its maximum1 ! fuel is inject$ directly into ! cyl9d] )\t hav+ be5 previ\sly vaporiz$4 ,?is is ano!r feature 9 :i* ! ,diesel motor is entirely diff]5t f ! ,otto type1 = ! latt] mu/ employ a c>buretor to vaporize ! fuel be=e x c be admitt$ to ! cyl9d]4 ,b inasmu* z !re is already a pressure approximat+ #ejj p\nds p] squ>e in* 9 ! cyl9d] ( ! ,diesel motor at ! "t ! fuel is inject$1 !re mu/ be a =ce beh9d ! latt] ( #gej or #a1jjj p\nds p] squ>e in* 9 ord] to enable x to ov]come ! resi/ance ( ! highly-compress$ air 9 ! cyl9d]4 ,9 %ort1 ! liquid fuel is spray$ directly into ! cyl9d] at a pressure ( #gej or #a1jjj p\nds p] squ>e in*4 ,?is trem5d\s pressure is suffici5t1 n only to vaporize ! p>ticles ( fuel z soon z !y ent] ! cyl9d] f ! nozzle1 or atomiz]1 b to cause !m to bur/ into flame1 z well4 ,9 o!r words1 ! compression ( ! air previ\sly has g5]at$ suffici5t heat 9 ! cyl9d] to ignite ! fuel imm$iately on its admission4 ,! fuel cont9ues to be inject$ into ! cyl9d] dur+ ! great] "p ( ! d[n-/roke ( ! pi/on4 ,9 ?is respect1 also1 is ! ,diesel motor radically diff]5t f ! ,otto type1 = ! latt] receives its full *>ge at "o "t & fires ! entire am\nt 9 a s+le explosion4 ,9 ! ,diesel motor1 on ! o!r h&1 ! ignition cont9ues z long z fuel is admitt$1 & ?us ?is eng9e is ( ! int]nal combu/ion type 9 ! /ricte/ s5se ( ! ^w4 ,x is1 aft] all1 ! expansion ( ! gases due to ! heat ( combu/ion t produces ! p[] 9 a gasol9e eng9e1 & if ! fuel c be s admitt$ t x c burn dur+ ! great] "p ( ! /roke1 a high effici5cy w be obta9$4 ,! exhau/ gases ( ! ord9>y two-cycle motor pass out ( ! exhau/ port z x is uncov]$ by ! desc5t ( ! pi/on4 ,^? t rema9 are =c$ out by ! sudd5 admission ( ! fre% *>ge1 :i* is deflect$ upw>d & is int5d$ to scav5ge ! top ( ! cyl9d]4 ,b x is claim$ t ?us employ+ ! fre% mixture z a scav5g+ ag5t is wa/eful ( ! fuel-p]meat$ *>ge & does n conduce to effici5t runn+4 ,! sy/em is simple 9 ! extreme1 h[ev]1 & does its "w well 9 small in/allations 9 :i* fuel economy is n ( vital importance4 ,b 9 ! two-cycle ,diesel type ( eng9e1 ! high pressure ( ! pure air is us$ = scav5g+1 & z ?is is admitt$ ) s l>ge an initial =ce1 ! exhau/ port may rema9 uncov]$ = a long] p]iod ?an w\ld be ! case 7 ! air to rely entirely on ! up-/roke ( ! pi/on = its compression4 ,!n too1 :atev] air may escape conta9s no fuel1 & consequ5tly effici5t scav5g+ may be obta9$ )\t wa/e4 ,at ! high pressure at :i* ! fuel is inject$ into ! cyl9d] ( ! ,diesel eng9e1 practically any grade ( gasol9e1 naph?a1 k]os5e1 crude oil1 or o!r =m ( petroleum c be vaporiz$4 ,! compress$ air employ$ 9 ! compression & injection ( ! fuel is also us$ = />t+ ! motor1 = ?is is n a type t is am5able to h& crank+4 ,?us ! ,diesel type ( eng9e c be run 9 any wea!r on any grade ( oil fuel1 & z ! c>buretor & electrical ignition sy/em are absolutely elim9at$1 two ( ! great s\rces ( tr\ble ( ! automobile motor are abs5t--& ?is feature1 alone1 ev5 m ?an ! sup]ior economy ( op]ation1 w appeal to ! av]age motori/4 ,j :5 ?is type ( motor w be tak5 up by automobile design]s is difficult to /ate4 ,! ,diesel type ( eng9e has prov$ s wond]fully successful = l>ge /ation>y p[] plants & = m>9e purposes1 & its reliability is s absolute on all grades ( fuel1 t ?is motor may solve ! fail+-gasol9e-supply problem4 ,z yet1 ab\t #ajj horsep[] is ! smalle/ unit t has be5 made 9 any quantities1 b x 0 rec5tly ann\nc$ t ?is type w\ld1 9 ! v ne> future1 be built = motor trucks & o!r comm]cial vehicles4 ,consequ5tly1 x is well = all ^? int]e/$ 9 ! application ( ! two-cycle motor to ! automobile to und]/& ! elem5t>y pr9ciples on :i* ?is radically-diff]5t type op]ates4 99 99 99 99 99 99 ,transcrib]'s note3 ,inconsi/5t hyph5ation has be5 reta9$ unless "o =m pr$om9at$4 ,! foll[+ corrections h be5 made3 p4 #ai ,?is give a mu* - give *ang$ to gives p4 #cd purpose ( cleann+ - cleann+ *ang$ to clean+ ,ev]y?+ else has be5 reta9$ z pr9t$4