South Bend News-Times, Volume 36, Number 236, South Bend, St. Joseph County, 24 August 1919 — Page 21

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mni).v, rr.rsT 21, ini!. Motor Cars NEWS OF THE AUTOMOBILE INDUSTRY 7 Good Roads

THE SOUTH BEND NEWS-TIMES

How to Locate and Distinguish Various Knocks in Motor

cf th

Automobile Expert Explains Causes for Various NoUes and How They May be Corrected by the Motorist Himself.

'.v. a. If lco ainl In the (hm-

in rt will rt Uii tinii 'K C 'A OSS Ol

pow'T. A loos.- priming or ptrocVc nets sintil irly to ;t broken

! .-pirk pl'Jfr corf. j A I'-os'- fiy-whcrl will also caui-o I a t-oit of dull knork, which is not ! so notica hi'.' when the tar is pulli ! ir.t;, t-'it Incomes juitf notict.il'11 j wh-n the clutch is di.-ni?arpl. 1 1 1 to Locate Knoi ks

Thr art' several

i.uly and which, an a rul'. K' ".c rally understood. ur.Ic h;i.s Lfcomo an fxprrt in thi.

a r- not J Immp

-s or.? i lir..

MAIN" nKARINO. This i usually !etrtcl by a

notioaMc !

bird bump bini:

throughout th motor. It i.-- caused by t-nd play in the shaft. loose-fil

ling iiarinK. .corod, seizco or i

burnt-out barinirs. In th? latter c.k-cs the motor will roan Martine when cold. On a thrf-e-brarinc.

or thud. The best method to

!o.at it Is by Fhort-circuitlr.& tho park plug; when two knocks will be noticeable, since the explosion pressure Is eliminated. Connecting

rod knocks may be caused "by

I twisted rod. loose j bearing, burnt-out

I play.

which mav be

BY C. T. SCHAEFER. Motor knocks may re due to four distinct causes

ij fined :is follows:

First That due to the exhaust. Second That due to lost motion in moving parts. Third That due to the deflection of parb. Fourth That due to the vibration of parts. In this article we will principally consider noise, commonly

'öiiiw ''" ii c uuc iu io-r. motion, most eeneraiiv ,.

methods of lo- i four-cylindrr crankshaft it is very

rat motor knocks; houewi. t hv . M. t. ä. . . ,, J ' netrmr the end or center bearings

most po.-!ive ii;-iuii j.- i'j i u- n.--I of what may be ailed a listening ; rod or by th of a stethoscope. ! A lori wooden-handled ucrew- ! driver forms a good listening rod. 1 The I'.at end is placed against th- ; cylinder or crank wall and the ! ... ... T t-511 nnrc.

,i.i.u,- -, - the end 1 earings knocks come sing

sarv to trv arious .umii uum ,, , .

f you ome in close proximity of tic ! i;nnrl- whf-n it tan be heard very

i distinctly. In some shops a spe

i ciat tool is provided for this puri -

made from a piece of sstcfl

jare the ones producing the knock, j Sinct- the center bearing has a p!ston and connecting rod on each Fide of it. and the explosions in the two cylinders follow each o.her at equal intervals, there is a peculiar douhie knock, whereas on either of

,inr with a wooden handle, and

Known as wear. It should be remembered, however, that in the fa metal plug in the bottom. Demajority of caes the third and fourth causes of noise can bejtHctinK lh" kntxk is fulte Sirnii'-. t'irA rtrrriv to locf motion r.r m.i- Ac U .t,:.- J however, its actual location is a

j problem not so i;imi i-fim-u n r- -

and some )ieier to use a

y and at e.jual time intervals. With

a ball-bearing crankshaft a rum-

I bling noise will exist if the races

are chipped or the balls broken. As

a rule, tae exact location is difficult to determine.

bearing, scored bearing, or side

I ti the case of a seized or

burnt-out bearing the motor will also groan when starting cold. The connecting rod bearing will make a much louder noise than a piston bearing, as the latter will make more of ;i tapping sound than h knock. Another good Indication of a connecting rod bearing: knock is that the knock will not "be near so prominent when the spark Is retarded with the motor running idle.

roXNKCTING ROD. This in a characteristic

riSTOS TIN". A piston pin knock can be easily distinguished by a sharp metallic noise, occurring twice when the spark is short-circuited. The knock

will appear regularly, and it is very

ery sharp when the engine is pulllnjr

hard The neck can also be located by speeding up tho motor, then closing the throttle suddenlv. In

sharp I doing so you will get a double

knock which is very sharp. Pis- knock will c ton pin knocks are caused by j speeding up.

cracked or broken pin. or a or badly worn member.

causeu v

tight j releasing the .-pitch and ro k ! t'.y-wheei back and foith

har.ee p. the motor l

tan be located by

z the

It is

:it 1 1 r. c

loose rittir.g

r-c a r.r gs. heirir.ps.

e f! i or ".

.IV

r T r

T!.MIN II -:.Mt S

PISTON". A piston slap is a sharp slap, easily detected when the t-park plug it short -circuit? d and the- pet or relief cock left open. The clearness

. V 1 V . '4 l.l t'4'X.i ouiov . i v ' v r A i t

i holts, broken holts. or haI-:'ttinc rlr. i

not i

e.l:

kevs and sp'.ir.'-s. There is

much danger of mistaking a !oo

wheel, as it will create a cor.di-

; tion which appears: t 1 v .-.h iking ! is i:nera!l

of this slap will vary with the size i the car to picet s. i :r.f or a

i r

taithts A tappet kno. k is often er. our- i

tered and is difficult to remedv on tics

light -spot-, I motors. ! :s a brisk tap , slightly

of the cylinder and the metal used in the piston. It can easily be located when th? car Is running at the usual driving speed with spark lever set. Then, by varying the spark lever, the slap will continue or cease. It can be eliminated for a short time by injecting heavy oil in the cylinder. This slap is caused

nv a large cylinder .bore, small tus- ! that is not square, or a

ton. or a tapered piston or bore. A I tion of these causes. Nois caused remedy occasionally suggested is to j by excessive clearance can be rem-

offset the piste n pin hole when renewing the piston. A broken or loose ring1 will be difacult to locate.

ditlr.guhe ; r-y r. r h-.. ni in ::: r.-!

and can ;s.!v be d: tcrt, ind ! sounding the timing err cu- with, a scrrw ilri-r or t-tho.-.pv Thi"

i.Tur-d by worn ' e i r -

e thi:

r;r: gs

'.v i ; .

it h !: -r.r. r1 f r, . s aj-e v r -aus--d by after oerh i ilfor the rrvilv-

such ,; t r i

üit rf ' ;::

or kr.ock. and is caused by execs- . parts ; h mc r. sie clearance. bent valvo stem. ;r;ire and i;s :a'

sticking, f'at and out-of-round roll- j proper

ers. tent valve spring. or a seat Inc:. The clear an;

shaft and ' onr.ectir. g rods in i f motors is very small, and rare must used in replacing o;ts oi! ;-

edied by adjusting. i pers. ec. locating mat.r kr.- i:s

is luit-1 an art.

I.OOSr: CAMSHAFT. become

and or.

tl.cier.t through

and is generally diagnosed as either ': A loose camshaft is very rarely j practice and aboh:te of the abv.ve two knocks. 'encountered, and usually registers a j tion while on the hunt. ,dull thump. It is very hard to d:s- ; velops the vr.so so th

LOOSE HA'-WIIKEL. (cover, due to the pressure of the . are the different This is distinguished by a hard. 1 valve springs, as this prevents the j tlnguished. but continuous rattle or a series of: hearings from showing wear. It i ! located.

sharp knocks, particularly at low engine speeds. The nature of the

c.i :

cr entra -tri..; ' ot o;-.!v

P'vVs a s . ' " : -re a:s- s; dil

sometimes located by excessive ra t - J Co Tight. IV.?. b' American tling of the timing gears, caused by tomoV.V Di-'est.)

r fers to "motor knocks," we will consider the engine only, since this Is one of the most intricate problems the driver or repair man h is to deal with. The problem 'onshts of distinguishing and finally locating engine or motor knocks. Caum of Nol.s Xoi;e jn the engine ma" te due to any or all of the several causes. The crankshaft being a very common source of. noise. When its b-.ringM become worn the alternating stresses due to piston and eonin otiüg rodn cause it to defect from its true course and pound on the sides of its bearings. Also, if the ignition occurs too early In the ftroke the piston will be forced down on the shaft and cause a bad knock. This may also arlso from preignition. The camshaft, although not subjected to the extremely Kcfere service of a crankshaft, is. nevertheless, a source of iiois If the bearings become loo.--, the valve springs, when compressed by the lifting cam. will

force the cnmsnait away anc inus j cause a light tapping noiso which J

U extremely hard to locate. As there aro eight cams on a fourcylinder motor and more on a six. eight, or 12. this nois will become ;il most continuous at uniformity hlu'h speeds with even slightly looso i e.t rings. IMstoii Of ton Txoso. The piston often becomes loose on its pin on account of Its location, .-nil difficult of providlrg lubrication due to heat. As the piston changes its direction twice for evi ry revolution of the crankshaft, the noise will be quite, pronounced with the slight wear In the bearing.

This also is true If the rings aro i

loose in their s!otr for they will .-top every time the piston changes; its direction. . After long use the I cylinder becomes oval-shaped, ow- I irg to the angular thrust exerted ' i.y the connecting rod, and as th? , piston becomes worn on the same j surface a decided looseness will resuit. i The connecting rod having a j ) . aring on each end. is a very proli- j f,- source of knocks. Its direction j i changed twice for every revolu- ; tu-n of the crankshaft, and there- j foi anv wear is shown up by!

pounding or knocking at each n-M-rsal. The whip of the rod tends ,. throw it from sid' to side and looseness which may exist will ause knocks. Valcs "lake Some Xole5. Valves and tappets necessarily produce some noise, because suffiuent clearance must be left between them to r-llow the valve to s. at firmly. When this clearance

on.

becomes excessive there is a s-ton : vt.-thi.mne. as used bv nhvsician;

tion

locating irregularities in the ac-

of certain organs id' the hu-

at each lift, and With all of these

man bodv. if consists of a piece or noise is quit? pronounced. With j h;m ruM,rr connected by rubber the overhead valve there is a great- ' tubes to the observer's ears. Only

er possibility for looseness and side play with its resulting annoyance. With slide and rotary alve motors this is practically eliminated. Imi Cranks A No C ii.uso. Ijoose rank .and camshaft bearings will change the center distance between the timing pears, thus allowing these to mesh tinevenly. Improper fittings of bearings in overhauling and adjusting will also cause this uneven meshing of gears. Bent shafts will also cause the same trouble. A hissing noise or whistling screech is produced occasionally when the gaskets under valve plugs, cylinder heads, etc., are not tight. Spark plugs will cause; the same sort of noise when the core breaks or becomes loose. Inlet and exhaust manifolds will also cause Viiss-

the sounds that are produced in the immediate vicinity of the point at which the instrument is applied are heard in the instrument. To determine whether a knock really exists, the engine can be run at arious speeds, and the car is driven over a smooth, isolate 1 road. The isolation provides quiet surroundings, while the smooth pavement r,x( hides all knocks and rattles of other chassis and body parts. Various Knocks ami ('aus.es. In t!r following paragraphs the various mote :- knocks are desc-ibed. together with the cause. In compiling these paragraphs, we ,tre endeavoring to make this information as clear as possible. in cc-der that the repairman may use this portion of the article as a trouble shootiiv: chart for locating and diagnosnig these intricate problems which arise

A Dark, 'Stormy Mi

on a muddy road

Sometime you may have tire trouble at just such a time and in just such a place. To change or fix a tire is a pretty unpleasant job. We have a service car that is ready to go to your assistance at any time from 7 a. m. to 9 p. m. no matter where you are. It is equipped with everything needed to remedy tfre trouble, no matter how bad it is. And in our shop we do vulcanizing and retreading that makes your tires just like new or we can sell you a new tire in any of the leading brands. We also have a complete line of accessories.

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MAIN 2804.

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NOT SECONDS All new, fresh stock, while they last at these LOW PRICES, chance to get CORD TIRES at lower prices than fabric tires.

Your

RIB NON-SKID ! I.Nt Trier Our Trice List Trice Dur Trice 32x4... $44.65 I $23.81 $46.90 I $25X)T 33x4... $45.85 $24.45 $48.10 $25.65 34x4 ... j $47120 j $25. 17 "$49.50 j $26.40

NOTE WHAT YOU SAVE.

Other Sizes at Low Prices.

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Announ

THE OPENING IIIIIIIIIIIIIIIIIilMIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Oi

144-146-148 Lincoln Way East

ON SEPTEMBER 1st THE NEW i i 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 m 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ; 1 1 1 1 1 1 1 1 1

TO)

Corner of Jefferson Blvd.

AGE

This new building made as nearly fireproof as modern construction can make it was built especially for a garage by L. J. Casbon at a cost of nearly $35,000. With its storage and repair rooms built of concrete, beams that were specially constructed by a Chicago firm, and the latest, most 'improved fire apparatus, car owners are given'absolute protection against fire. flfl Centrally located, two blocks from-the heart of the city at the intersection of two of the main thoroughfares, it offers the ideal storage place for local as well as transient motorists. The storage room the main part of the building, on the ground floor is 72 feet wide by 175 feet long, giving 12,600 square feet of floor space for the storing of cars. The repair room, located at the rear of the building under the main floor, but with an outside approach, will be equipped with all of the modern machinery known to the garage world and will be under the charge of expert mechanics. A gasoline and air station will be maintained and a complete line of accessories and motor helps for all makes of cars will be handled at all times.

We would be pleased to have you come in and equipment.

at anv time and inspect our new building

CASBON

lk. TTft

ITT3 f i A

Corner Jefferson Blvd. and Lincoln Way

L. J. CASBON, Proprietor

i iAl

P4MFl MAIN 2251

CO,

126 EAST JEFFERSON BLVD. 's.''?.-;: ''vs. ,, i-y.'v y-'Viifirr-i 1 ti 1 1- Uitti '' -