New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1918-08-11
When the Engine Gets Sluggish
Look for Compression Leah,

reasons for this. First con
voiume OF gas used; in order ~ the
use of the power generated % make
burned gas the piston must tro Wy the
of the cylinder. When il 10 ' s out
way in the cylinder the spaca az the
the piston which contains thu ssoovs
OF gas is only about ona-ff,b Ssnafes
whom the piston has travelled y. VI mat
way down: Therefore, by draw al the
full cylinder of gas and tbsn IN
pressing 1t into small space q. sen'
top. about five times the voI,n 'as
gas is used, giving 1--WE timss '' -. q
power. 'eS The
Second when the gas is comprises
1t viii 'gnite much more ready We, s
burn much more evenly In fact !. aug
possible to have so much compress;ass
that the gas viii ignite from that l ssmsa
alone. and frequently there is pre' ssuse
ton because of too high compress sa,'
Loss of compression, therefore, ms ,va.
loss of power and waste, because q snM
cylinder of gas is taken in and os, lI
part of it used, and the explosions WY
weak and irregular sfs
There is something of the ac,;ou
q coil spring in COMPRISING tba -. VI
The force of the compre ss;on gas
would send the piston back to q a nA;Ae
where there was no comnress;or f ps
Just at the point of highest comrsss
sion, spark is introduced. which WHIPS T.
chemical action, expands the ras 80, ~
idly, so that between the forces of 10y p'
preston and expansion the p;s,o .Oni'
driven down with great power. ''' Is
In addition to the push rods hi.
adjusted so close that they ho,d .s
valves open, there are numhsx 'us
other places where loss of Commas; VI
might occur. There are the valve s os.a
and IN some forms Of constructor ~
valve cages, where there NAV he ' I.s sIue
spark plugs, at the base whore t.S
screw into the cylinders. and some.; ,ssy
around the insulators; pet or n,;.aiN
cocks, both at the base and lining =.
valve. Where the cylinder had. ue
removable, there might be Iaas ere
tween the head and the cylindsr S Ie'
cause of poor gasket or fa;lvs. w.
bolt the head tight. 'e 70
If the cylinders are worn nv, =,
round, or have scores or ridges ~. VI
them, the piston rings will not mal.
tlght Joint and compressed pas ANY "',s
leak by the piston. Piston ines soS VIII
times lose their elasticity ~ 90me'
gummed fast with burned oil and ore
bon, and no longer press frmlv acs isl,
the cylinder walls, and occasionallr r' AZ
retaining pins break off and tba s;s me
work around until all the openincs "ss
IN line; in either event gas leaks ne a's
Lack OF lubricating oil will cause r H..
same trouble. This usually NAV ho WY ~
eected quickly by knocking in the NV
sihe. In some cases carbon denos;,aa
on the exhaust valve seat keen O'' .ta
valve from closing and affects tho tho oo WE
preston. '"e eoa'
To test for compression. each crl;r.
der must be dealt with separstey
Open all petcocks except on the cyljn.
der to be tested and turn the enrins
over with the starting crank numbsr
of times. Where there are no petcoek,
remove spark plugs. A decided oppos.
sltlon to turning the crank should he
felt once in each two turns, for the
upward travel OF the piston every Other
revolution should be COMPRISING the
gas. II no such resistance is felt. or
if it is less for the cylinder than 70:
others, or if there is p resistance
which quickly decreases while the pis
ton is at top OF compression. it will be
: an indication that there is a leak
somewhere and tests should be made
TO determine where it is.
Leaks past the piston often may be
located by removing the breather pipe
cover and listening while the engine is