At The Wheel

NZ Truth, Issue 1177, 21 June 1928, Page 18

At The Wheel

A LITTLE HOME-WORK Grinding In The Valves Is Easy Qne of the jobs which many owners who do most of their own work do not care to tackle is that of grinding m the valves. IT must be admitted that this process fair order; it is the valve itself that calls for some amount of knowledge suffers. and skill, but it is not at all beyond If the pits are deep or the face the capacity of anyone who has a rea- burnt, the valve should be taken to a sonable amount of mechanical "sense." garage, where new faces can be cut at Probably, many owners will appre- a small charge. Ciate instructions In simple language Taking the valves now as ready for as to how to set about putting the grinding m, _y screwdriver or brace, and valves m order. ' bit and fine and coarse grinding paste The first job, of course, is to dis- will be necessary, mantle the valves, setting aside springs First the coarse paste is used, and and other parts for cleaning. \ small amount is spread on the face The valves, if not numbered m ro- or the valve, tation from front to rear, should be The valve is then dropped on to the spotted m turn with a punch, one hole seating, and with a firm pressure it is for No. 1, tWO holes for No. 2 and SO rotated backwards and forwards from on. a dozen to twenty times. •- . The valve stems and the faces An effective method is to give should then be scraped free from car- the valve three backward and forbon. and the faces, both of the valve ward movements, then turn it oneand seat, examined. sixth turn, and continue until the I In most cases the inlet valves will circle is completed, be found to be m fair order. The valve is then lifted, the • old They can be tested m this way. t ■ wiped off , and fres h paste placed | The faces are wiped dry, and half a on dosen chalk marks are made across hen a br jght circle of clean-cut the face of the valve face at regular motal is visible around the whole face, distances apart. the flno p aste can be used, and the The valve is then allowed to drop grlnding continued until the chalk on to the seating and given a quarter mark tesfc shows it t0 be seating perof an inch turning movement with a f ec tiy all round. screwdriver pressed well down. lf - th i s methQ ' d is followed out, the The valve is then lifted out, and work will be pleasant and easy, and all the chalk marks should be cut results certain. „*,,...» through where the faces of the It mupt be borne m mind that grindvalve and seating have come into ing must not be continued any longer contact. than necessary, and that it is of no use whatever attempting to grind the face If all the marks are not cut cleanly of a valve which has been grooved by tho valve needs grinding. contact with the seating. The exhaust vaives, as a rule, will A perfect seal can only be obtained be found to be slightly pitted and even on a valve the face of which is perburnt. fectly uniform and free from grooves The valve seats generally will be m and pits. liiiliiiiimiiiiiimiiliiuiiiiiiitimnniiiiiiliniiim limn iimtiimii nnnn iMimiiiiiiiimimiiiiiiiimm mntimimimii mmniiiummmimmmmimiiinnniimmmmiimimi „„ ,„„„ ,mmiiu__ mmimiiimiiiiimmiiiiiimiilim ilimum Ul|il uiillillHllllllllllllllllllllllllllllHllllllillllulltl.lllillllllllllllllllllllllllllllltuiiiilUMllililiiilliiiimillillllilHiilillllllli