Chapter 18

Carburetters, Coolers, Etc.

The Benz and the De Dion motor tricycle carburettors have already been described; these are what are termed surface carburetters, the  air passing over the surface of the hydrocarbon. This carburetter works well, but on a rough road it is liable to give off vapour too rapidly, the vapour being in excess of the pure air, and reducing the power of the engine. The writer has to a great extent overcome this difficulty in his Benz by keeping the level of tile petrol in the carburetter much lower than is usual.

The Maybach carburetter is used in the Daimler cars and most of the English and French voiturettes. It is of the spray type, and is shown in fig. 56, which is taken for Maybach’s specification; d is the float which cuts off the supply from the pipe e, keeping a constant level of petrol in the chamber a; the nozzle b2 is placed in the suction pipe of the engine, the incoming air sucks the liquid out of the nozzle in the form of spray, and thus it becomes impregnated with petrol vapour.

It is only fair to say that Maybach’s patent appears to have been anticipated by an Englishman. E. Butler. F. C.Blake, of Hammersmith, has lately brought out a spray carburetter in which the spray nozzle is fixed in the centre of a flexible diaphragm, which at each suck of the piston lifts the valve seat off the valve and admits the petrol to the mixing pipe. As there is an adjusting screw to the valve below the diaphragm, this arrangement should work well with hydrocarbons of considerable variation of density.

In the early cars no great attempts were made to reduce the temperature of the water used for cooling purposes, but in the last two or three years radiators have been adopted. These are pipes through which the water is circulated, generally by a pump; the pipes are covered with a large number of plates or grills soldered to them, and offering a considerable surface to the air.

Clarkson and Capel’s radiator is shown in Fig. 57. It consists of a helix tinned copper wire, bound spirally round the tube, and then soldered to it; this wire offers a very large surface to the air. This radiator or condenser is light and efficient.

The Stanley steamers imported into England are frequently fitted with these radiators to condense the exhaust steam, for in the United States either the dryness of the atmosphere renders the steam partially invisible, or there is no objection to a car being followed by a cloud of vapour which would not be tolerated in England.