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

VAPORIZATION IN THE HIGH-SPEED MARINE ENGINE. 73 a series of fine apertures drilled in a bar t that extends across the openings a1, a2 for the admission of air ; this bar is drilled lengthways and communicates as shown with a duet in connection with the fuel supply. Over the jet-block, shown separately in plan, there is a com- bined spray chamber, mixture regulator, and throttle li? the base of which is formed with a rectangular opening h1, that coincides with the openings a1, a2 when the throttle is in full-open position, as shown in elevation and part plan section, as at V P ; the position of this for running slow is as shown in the part section at C R, with the throttle lever moved over from o to s, thus leaving only two fuel apertures uncovered and a corre- spondingly reduced opening for air admission. The mixture is vaporized during its passage through the two crescent-shaped passages v in a cast-iron block heated by the exhaust from x, which fiows partly arouncl the block and in part through a central passage x2, on its way to the outlet pipe x3. In accordance with this system all the air supplied to the motor passes through the vaporizer, yet it is claimed that a compression of over 56 Ibs. can be used without a water drip in motors up to 40 when the cylinders, four in this case, are properly cooled. In anot her variant of the single-jet type of exhaust- heated petrol-paraffin vaporizers—the P.C., or Cottrell, and illustrated in Figs. 55 and 56—the spray nozzle is arranged vertically in the centre of a double-coned choke-tube c, and fed from a float cistern / fitted with a two-way plug t, as usual ; but according to this system —adopted in the Forth marine motors—only about one-third of the air with full-open throttle is drawn through the vaporizer; this, as shown in the cross-