INTAKE SILENCERS

Rotorua Morning Post, Volume 2, Issue 222, 13 May 1932, Page 2

INTAKE SILENCERS

HOW NEW ADJUSTMENT TO CARBURETTOR WORKS Everyone is more or less familiar with the noises which become audible at wide open throttle such as occur in hill climbing, accelerating, high speeds, etc., and commonly called "power roar." Experiments by manufacturers both in the laboratory and on the road located the cause for this noise, not in the exhaust hnt rather in the intake system. An intake silen'cer removes this objectionable. noise and imparts the feeling to the driver and other occupants of the car that the engine is performing apparently without effort. The silencer is that developed by Buick in conjunction with engineers of the AC Spark Plug Company. The principal of operation is based on the phenomenon of sound waves. Every sound has a definite wave char-

acteristic and the pnrpose of the intake silencer is to induce a counter sound wave opposite to that of the original sound wave emanating from 'the intake system so that the two waves counteract or neutralise each other. To malce the silencer effective over a wide range of sound waves, multiple chambers are used, each of which acting alone wonld neutralise one definite wave but when acting in series spread the neutralisation over a wider range. A device of this land properly built offers no resistance to air flowing into the carburetor.