Show lAl l Bar i wI I II FITTING ENGINE H rI r 9 v I BEARINGS EJ I r I j B By y Barney Old Oldfield jell C Copyright p J Syr 1911 u tc by Ilan In lac inc 1 Feature J Syr u Among tho moat most Important parts of or the Internal combustion en engine engino are arc arc tho the I hearinGs bearings which support the crankshaft and t connecting rods Without these parts the operation of or the engine would bo ho impo impossible and when the they are aro not In proper condition the operation of the engine Is Js Impaired in corresponding degree desree In Jn this country countr these engine bearings are always what are arc called plain bearings bearings bearings bear bear- ings that thC is to sa say a bronze e shell with an Inner lining of or babbitt bC composition Almost always alwa's these beatings bearings are aro made In two parts In such a way woy that when they are fitted together they form torm a complete cylinder cUnder Between tho thorn halves arc are placed shims which may be of or solid or of at laminated metal In operation the tho crank crankshaft hat revolves inside this tills bearing resting directly on ott tho the soft metal lining Obviously Ob unless unless unless un un- un- un less the entire works orl s are arc copiously lubricated the friction generated will melt tho the soft sort metal and let the shaft down on the bronze shell of the bear bear- ing But Dut short of ot this the natural wear gradually erodes out a portion of or the lining metal so 50 that the crankshaft t In turning develops a 3 little pl play This re results re- re suits in a knock an and when this we ve know that it is time lime to take up the tho bearings Now taking up engine bearings is no ob cob to look 1001 forward for to under the tho best I circumstances It requires considerable skill and md experience beyond those possessed possessed pos pos- Jess cd b by the ordinary car owner No Noone Noone o one should try to adjust the bearings without watching a skilled mechanic do the Job first but at that I think I Ican Ican Ican can give some seine hints on how to do the work which will bo be valuable to my readers The only entIre entirely satisfactory way of fitting titling tho the connecting bearing Is Isto Isto to tako take the en engine lne out on the work worle workbench workbench I ben bench h and do tho the fitting tiltinG when the crankshaft has been removed Tho The re moro removal of ot loos looseness ness the shims or 01 removing a a. lamination Is 19 not proper properly adjusting the bearings s. s It Jt gets rid of the pIa play temporarily but It does not give an accurately fitting bearing When hen th bearing is simply tightened against t the e shaft t In n this way the original origInal original inal looseness will develop again aGal before long Fo For this reason the only wholly satisfactory method of or doing the tho work is to put t the engine on the tho bench and proceed as Tho The craM pin or that part of or the tho crankshaft that runs In the connecting conn bearing is spread d lightly with Prussian Prussian sian scan blue or or r lamp black block mado made Into a n. paste with with a. a little oil The connecting J rod shims aro are made just a trifle trine smaller smaller smaller small small- er er and tho the connecting rod Is placed In Its proper position on n the crank pin The rue H crank pin cone conn connecting cling rod is then turned around so 80 that tho the bearing surfaces surfaces sur sur- faces ices will rub rab against each other Aft Aft- r r. r this cr has been done dona about a n. dozen times tho the connecting rod Is removed and a cloth Is used to take off oft the excess color from the bearing This will leave lea th the tho high spots o on the bearIng bearing bear bear- Ing showing These high Mh spots are aren arenow are arenow n now w remo removed d b by means of at a a bearing I Scraper Sometimes tho the entire half 0 of ofa ofa a n. bearing will trill show high color and I I obviously It all aU needs scraping When only onh scattered spots sho show color these must be carefully scraped caro care being used that the cuts do not go So too deep The cuts must be cleaned so that tho the petal metal is not left with a number of at rough rouSh spots This scraping process will m have hn-e to bo be o repeated a number of ot times the tho crank pin pig colored and the therod therod therod rod placed n Sn n position and twirled a few ow times removed cd ana ane tho the high spots scraped after aHer each operation When hen done often orten enough there this hns has be been n is known as a will bo be formed what bearing surface that is 18 to sa an say little surface of or tho the bearing spots all over o both halves of the bearing v while the connecting rod will turn freely Creel on Its It t can pin It must not be so tree free that bo whirled round around roun and ond yet ct it must not of great amount be bo so tight that an any effort cHart must be used in turning it Tho The ideal l bearing surface will show a small high spot about o er every thirty thirty- second of an inch This pr process s of oC fitting fitting fit fit- ting mus must be carried carrle out with every connecting rod loci bearing and tho the at attempt attempt t at- tempt Is made to got get eari elc bearing to tofit tofit fit tit with the same degree e of or tightness Tho The crankshaft b bearings gs are scraped rod wa as tho the connecting In tho the same sarno way bearings 8 but It Is not usually possible for tho the car r owner to tako take the tho engine out of oC the thc chassis and operate te on the work bench In this case caso the best the tho owner can canto rio do as a general sener thing is to scrape the lower half halt of ot each crankshaft crankshaft crank crank- shaft bearing It Is b by far best to scrape the crankshaft bearings s with the connecting rods lods detached from the shaft In this wa way a tho the exact degree of oC crankshaft cr bearing tightness may maybe maybe mayhe be he readily determined especially if It therod tho the rod bearings s are first scraped in Many Ian repair shops have Ime equipment for reaming ream ream- int ing bearings and then running them in This This This- means c ns simply wearing them down downto to the tho proper tit lit b by running tho the engine b by means of oC a C belt Obviously the car owner Is seldom In a l position to lo do this Two Important points are arc very er frequently frequently fre fro owner neglected by the tho car r when he is fitting crankshaft bearings s. s One of these i- i is ithe the removal of or end play and the other othor is shaft shaH alignment For example if It tho the rear bearing ls not Is-not not proper properly scraped It Is likely to throw the crankshaft out o of alignment with tho the clutch a condition which will make e endless trouble Also when on only I one bearing has been scraped and fit fit- td tod the shafting Is like likely 1 to be sprung slightly out of oC line lino and again trouble will result I mentioned the danger of ot end play which tends to cause causo bucking at slow car speed This trouble re results results ro- ro from worn tJan flanges es and when a flange Is badly worn It Is difficult to 10 overcome except by replacing the whole bearing In conclusion let me say this about fitting bearings bc while the operation is difficult and calls for tor real skill no I car r owner who alms to become a complete mechanic will want to pass pas the Job on to ther the repairman Ho He should not make it the first Job he ho tackles on his car but ho he should make It his aim to learn how to do it when he feels that his skill is able to meet tho the test of a real workmans workman's Job I Barne Barney Oldfield ld |