The Vaporizing Of Paraffin for High-Speed Motors
(Electric Ignition Type)

ROAD C AR AND TRACTOll MOTORS. 103 conditions and with different densities of fuel. The complete apparatus—shown somewhat diagrammatic- ally—is to scale for a two-cylinder 20 H.P. one-ton lorry, and will be seen to have several points of interest, including the total absence of spring-loaded valves, a combined mixture regulator and throttle, and a vaporizer affording the ut most facility for cleaning. The White and Poppe may be cited as another car- burettor that has recently been combined with a vaporizing attachment for the use of paraffin ; in this, as in the example above, the air and fuel supplies are both mechani- cally controlled, and again, spring-loaded-automatic valves have been eliminated. In this carburettor vaporizer, used on the Dennis and other commercial cars, the vaporizer attachment is merely a thick copper tube arranged within the exhaust manifold, somewhat as shown in Figs. 72 and 73 ; but differs in being of the full intake area, as on this system there is no supplementary supply, and all the air passes through the heated vapor- izing' tube ; also, in the use of an auxiliary carburettor close up to the inlet manifold, for starting and running on petrol, each being provided with a separate combined throttle and mixture regulator. In the construction of the carburettor vaporizer, shown in Figs. 76 to 79, there can be seen one or two somewhat peculiar differences from ordinary practice ; in this example, the Halliday paraffin vaporiser, applied to a four-cylinder touring-car motor, provision is made for the supply of moist air in direct proportion to the throttle opening when running on paraffin. The change- over plug t cont rolling the supply of petrol or paraffin from one or other of the float cisterns /. is linked up to