MOTOR NOTES.

Auckland Star, Volume LXXI, Issue 245, 15 October 1940, Page 10

MOTOR NOTES.

NEW SPARK PLUG. IMPROVED INSULATION.

A new high-tension insulated spark jilu;, one of the fca majw advajierrnrnU in spark plug doiyn for row than a decade. has been aanoonccd in America. All other component partof automobile ipiitinn have lirrn propts»ivoly developed diirin; reoent years'. Prcwnl day highconnpros«ion engine-s, however. required higher voltages'. and additional clwlirira] adjustments had to i«o made for virinu> Imdf. The new- high-tension plug is patterned after the insulators <«n JaightcnsioH power lines and transformer* and employs the same functional principle in preventing electrical leakages. The design of the jwiwlain insulator sleeve on the new plug is fluted, ir rid?ed. l»y "petticoat#." which not only minimise the accumulation of srroasc and dirt, but also add to the -iirfacc length of ihc insulator sleeve ivith consequent reduction in outride 'flash over"' or short circuiting tend- , •ncics. The "|>ctlicnj!»" also *erv<» to ■hed or break up the flow of moisture; <vor the porcelain surface of the insuatoj- sleeve. With the introduction of this type of neulator sleeve. spark piny* have now eached a .'tape of development comparable with other electrical advances. ■ Phe new plug. it is claimed, will not >nly enable cars to run longer distances 1 K-fore dirt accumulation causes the plu; ! o short circuit, but will also enable cars | 0 run much farther before it is neew- | ary to reset the spark gaps to avoid hort circuitinp. Ihe principle of the new plug is well | nown to electrical engineers. Kvcrv J notorist has Seen the "petticinatcd"" initiators in high ten-iou iinf« and transorrncrs. Electricity. which always 01 lows the path of least resistance, inds it easier to go straight through 3»e spark plug centre electrode to the iring point rather than travel the onger distance around the petticoats, .onsequently. the chancn* of short car- | uiting are practically eliminated. Even w the the points bum awav through r»ng usuage, it is Mill for the ■lectricity to reach the firing point, thus ' •nsuring longer trouble-free lif<. of the dug. If this new type of spark plug ' uglifies the claims made oa its behalf., io doubt it will make its appearand »n the Xew Zealand n«rket in due ourse.