The sun., 1916-03-05

the next orcration or stroke nf', me
completion or The suction s,rnh, b.. g.,
compress this charge ~ ga rp ,,.
rumplish this of coIrs" both utplu ,.i
exhaust valves must l"' absoluj,lv ar
tight A the crank pin passes tH~oue.
the are Ut "hutiom c"utr'' u.I u.
the piston travels upward. tbttpr = .,..
the charge of gas At "top r,u'r o..
when the piston H. nearest the c,'"-,,e.
head the charge Is fully cou3n.s.f
nid ready for ignition. At 'Li3 my',.,
The igui'iun syat,m Is 80 '!r,"d I" . H
delivers tn" spark at spark plus ~
This spark Is to the charge of ga oha'
the PERCUSSION cap IS To the loaded g'ir
When the compressed "h"rrc ~ gae
i1 ignitod the pistru IL instantly foi, af
outward due to the expansion 80 H..
hurning charge. thereby d,uNori.a
through piston "It" aud connecting YOU
- rotary motion to crank .haa "u
This X called U,c power stroke t''.
This has taken place "pnsi""rahl" Vas'r
products or combustion must y, cl m.
mated from the cylinder IN order '" re.
pare II for Il new charge. Therefore
iuSt before the piston completes N,
power stroke the exhaust valve "G' 5.
timed to op,u TO permit tn" hu-,o'
gases to cScap,. This exhaust Nal,,
l"maius open during all the tim, 1at
the piston travels up again. ln n
manner the cylinder t. fully clcpurd
TIL" upstr"i:" of the piston af'ct The
power stroke constitutes the rNhau,.
stroke. In this lnpuner four uIcra'ioa
ha," been completed, namely suction
stroke. compression stroke" firing s'ro,,
aud exhaust stroke From til. forero.
inr 1t will hc noted that the power e'-o'.
H. tby only iuptiis, Stroh,
I'll" necessity for proper ValS, tinins
becomes apparent Tile intake Na,r
must open wh"u the piston Icgir. E.
travel downward and " must clos q,
certain point to pr",cn, the piston pub.
uc this charge out Of tn" cylinder vh".
1t begins to travel upward ON the .rn.
preston stroke again. Iikowis, th, ~
haust valve must opoI ~ n point pf'e,
the expansive force Of til" firing chargr
has been rNrTt.d un tho piston. tn -
usually Just before til" piston reaches
hutiom centre on the firing etrnkc Like.
wise the exhaust valve ,loscs when iho
pisto has made the fun travel uuu arl
thereby eliminating all the burned gases
Motor" "f various makes differ ,lIsl'jv
AZ to val,r timing.
II must ais" he noted that tic e.. x
gear ~ a1d ~" ;lru at hair ru.
10 crdul shaft ~" rn complete ..,
fuuv strokes "f tine piston "iiuh a.H.t
"D'' mi,s, make two ruiu,l.,, .r.u..
tious. ~ Tia. mclr.tiul.. huvttt.. .
intake valve upcus only on the suction
STROKE. ia, ,;haust valve u9.is ,.,
ON the ,Ah.ti,t s,rnN". II,rcc to ICES.
49,, cnr timing gcars being driven At
half tim" speed
Tho cant shat, "N' carries tho t,f
which opcr,icy ,,3yc push rods ~. .-
cam j. am crr sla,,.d dc,ic. ATTACH.
,,,,.. can. .l,f. which q, rni.,iup ls..
pusn rod a." the .chy upcu'ue &C.. .
.G" ac,ii@, tic ros,sta't,c ~ y,..s
srrluc. "tt" ih,-, valve .4~.ug. Ia. .
necessary 10 insure nu,rl: lrt,or ." t.
,.l,,s Th,. ,Yf,, nlsh rod roller. "T
urc installed io i,~tuf uoiy"lcse ur, %.
,,.. ,-d ts.. .N,ulI '.lI,V closely Ns
..u.,nur nr Tin. cam rl. ,alyr srri,u.
of prun,.. design. insure Tins.
=, u,h, ~" .h,,. fs AN nncuirc %
,,,,,,,, ,.,i,, -.,,.,...,,,J valve uush .of
IN d,,,-.,.. n.rr,tis an adiu,tiu,., .
,., ,,',,. ri,,u r,L Ia take care ~ ~. b.
=, ,i,i. u,lu, and elsewhere in tho yg'y.
.r...,,,rt.r