Page 33 Advertisements Column 2

Sun (Auckland), Volume III, Issue 738, 10 August 1929, Page 33

A MESSAGE OE VITAL INTEREST TO MOTORISTS appotenie : ap po-ten" ik ) The quality in a motor spirit that ensures perfect Combustion This diagram shows correct combustion—tuith “Plume the appotenie motor spirt . * * appotenie [from Latin: ad (ap), meaning added to; and potens, meaning powerful ] possessing increased power; said of a gas that, being stable to heat and high compression will therefore neither audibly nor silently “knock” in a high compression engine. > i S 1 This diagram shows incorrect combustion—with motor spirit unstable to heat and high compression Plume, defying high temperatures, powerfully resisting the disrupting influences of high compressions, bums evenly and steadily. The expansion of the gas following this correctly-timed combustion delivers a powerful, thrusting push to the piston. It maintains this steady surge of power throughout the length of the power stroke, enabling your engine to deliver its full horsepower. Correct combustion follows naturally when appotenie motor spirit is used. Plume will deliver maximum power without silent or audible “knock,” despite the stress of hill climbing in top gear or the heavy-load strain of low gear “plugging” through sand or mud. When you use a motor spirit that is unstable under heat and high compression, a chemical change takes place in the charge shortly after the instant of ignition. The temperature and pressure of the ignited portion “A” raises the temperature and pressure in the remainder of the charge to such an extent that it spontaneously ignites, or “goes off,” in uncontrolled combustion. Flames rip through the charge, hitting cylinder walls and piston, resulting in what is commonly called a “knock.” Whether this “knock” is silent or audible, the propulsive power of the charge is wasted in violent, spasmodic expansion, which the piston cannot absorb. Retarding the spark, or cutting down to second, may cut out the sound of the knock, but it is simply a case of shutting the stable door after rhe horse-power’s gone. Write for our free booklet “The Connoisseur” It explains the appotenie quality still further. PLUME appotenie *Motor Spirit Prove the appotenie quality for yourself. Fill up at the Plume pump. 9PI 7 VACUUM OIL COMPANY PTY. LTD.