A NEW CARBURETTER.
Page 45
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AN ENTIRELY new carburetter, developed and manufactured hy Carburation (Temperature Control),
of Orkney Street, . Battersea, London', S.W. 10, is being Shown at Olympia during the present week on Stand No. 257 by London Motor Garage, Ltd. The difficulty attendant on securing correct proportions of the fuel supply to an engine mainly lie in the avoidance of " flat spots" or sluggish periods throughout the range from idling speed to. full
throttle opening. The difficulty is invariably got over by the excessive supply of petrol Which, while producing the correct mixture at the critical speeds, gives an excess of petrol at certain other points in the range thus making for loss of econosny.
In the C.T.C. carburetter, entirely new principles of carburation have been , brought to bear. By a dispositioning and proportioning of Parts, and particularly of tho relative areas of the jet orifices, a very high velocity of the liquid fuel (such as ha's been proved requisite to secure and retain vaporization) is maintained at, the low engine speeds whilst, inversely, the velocity at higher engine speeds is relatively lower.
In order to secure this end, the jet is•disposed in an unusual manner, viz., well below the level of the petrol, so that when the engine is inert there is above the level of the jet a substantial well of liquid fuel available to be drawn upon for instant supply as the throttle is opened (after starting up) thus giving what is always lacking with a sluggish oarburetter—or rather, one which is sluggish at certain critical speeds—rapid acceleration.
For starting up (always with throttle closed and without flooding) and when idling, the air enters the small air inlet and draws itsfuel from the pilot pipe, passing' to the engine through a small port in the induction pipe at the edge of the throttle. On a slight opening of the
throttle a second high velocity fuel supply is available, .through the second port behind the throttle. As the throttle is opened wider the volume of petrol standing in the nozzle and the well is available to enrich the air passing through the choke tube. At high engine speeds the well is. empty and air passing down the pilot pipe across the mouth of the calibrated jet assists vaporization. On throttling down, the well and nozzle tend to fill, thus providing a reservoir of quickly available fuel for the next throttle opening (incidentally catching the overflow and preventingwaste), whilst on a sudden 'closing of the throttle front full bore, the "flat spot" which could occur through the, well being quite empty 13 avoided by the relation of the mouth of the pilot pipe to the calibrated jet.
On the test bench and with an engine we have manipulated the throttle at various rates of, movement, and have found that "flat spots" areentirely eliminated. By the provision of the nozzle and well, the tendency for the petrol to overflow immediately the throttle is closed is entirely prevented. With the large supply of fuel in the well available for starting up there is never any need to flood this carburetter. The result is that with. the C.T.C. carburetter there is the greatest economy, the greatest efficiency at all engine speeds, and the most rapid acceleration possible