CURING KNOCKING.

Hawera Star, Volume XLVII, 11 August 1928, Page 15

CURING KNOCKING.

LEAD OXIDE LATEST TREATMENT. Some feiv months ago attempts, were begun in America to isecsure benefit, in the term of reduced tendency towards i knocking in engines, by the deposition j of special compounds upon the interior j .surface,s of the combustion chandler i and on piston - heads. This sch eme ha,.; | recentlv been advanced a stage further ! by road tests of cars with treated l and j indicated engines, and although, the rej suits were based upon rough and ready observations, it seems quite clear that advantage j® gained from, an anti-knock compound ‘“painted” on the combustion chamber surfaces. The compound used was litharge or ! lead oxide: a coating of this to a.thh ki ness of one-lvundiedth of an inch is said i ay chemical action and reaction to ah- ! sorb heat at th» moment of explosion that would otherwise give rise to knock- 1 I itig. and to restore it during the ex-. j parision ueriod. | j before thin scheme can be seriously i lionridered. however, as a practical afi ternative to tetr-a- end-ethyl fuels, a J /nod deni more information of a. definite and " scientific character will he iK-ed'ed. Dynnmomater lest.-, are required, in ewijnnction with some .such indicating i j instrument as is need to demonstrate , t'n anti-knock qualities of fuel dotes. | Moreover it is not enough to lanow that j knocking can. he cheeked. Another ; i it to lie determined is whether the ; ! effect- can lie achieved in the (manner . i described without loss of power. *