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

52 VAPORIZING OF PARAFFIN. which means about once a year, if only in occasional use as in a yacht or launcli. To clean out the carbonized deposit, the union-nut of the fuel pipe p is first unscrewed and the nuts holding down the cover k taken ofT, this allowing the entire vaporizing surface to be opened up. In an engine of this size—i.e., with cylinders 6 indies X 8 inches—no means other than a plentiful supply of cooling water is required to prevent thumping when speeded up to its full power of 12 to 14 B.H.P. at 550 to 600 revolutions per minute ; but when required to run slowed down for manæuvring or declutched, the running is steadier if a by-pass between the delivery and suction of the circulating pump is opened, so that the temperature of the cylinder jackets eau be raised. This size of engine when connected up to a cooling tank for thermo-circu- lation works better if fitted with a by-pass on the exhaust for regulating the temperature of the vaporizer, as illustrated in Fig. 42, in order to subdue the harshness of the explosive action at full load, and in engines of larger size, it is better if supplemented by a second by-pass valve on a pipe connecting the exhaust with the air supply, for the purpose of diluting the mixture with from 5 to 10 per cent, of inert gases, so as to furt her suppress any tendency to thump ; the method of carrying this into effect is shown in modified form in Fig. 41, where the three-way plug z, when turned to the position shown, connects the passage z1, leading to the spray feed regu- lator r1, direct to the atmosphere through z2, but when turned 90° eommunicates with the passage z3, so as to draw in exhaust gas in place of air. In the combined exhaust and lamp-heated induction spray vaporizer shown in Fig. 38, which is a modified