Motor Road Transport For Commercial Purposes
(Liquid Fuel, Steam, Electricity)

ECONOMIES : FUEL 165 The Carburati on Problem. The problem of carburetting air with. the heavier forms of liquid fuel, such as paraffin, in order to produce a homogeneous and dry gas for burning in an internal combustion engine, is one which is difficult of solution, and the obstacles which have to be faced can only be fully appreciated by those who have gone into the question th.orougb.ly. For the marine or stationary engine the matter is not easy, nevertheless, it has not a tithe of the com- plication which the motor lorry or car presents, for the reason that the loads and pistons speeds do not vary so widely in ratio to time, nor do atmospheric pressure and temperature differ in the same degree. With the average modern petrol carburettor the efficiency is not high, and when the amount of useful work obtained from any given quantity of spirit in relation to its latent energy is considered, it is easily realizable how far short of perfection is even the light fuel carburettor of to-day. The present day design of the internal combustion engine is accountable for a large amount of heat wastage, but that only seems to point direct to the utilization of surplus heat in order to volatilize the heavier forms of liquid fuel. The typical car or van carburettor is not capable of self regulation even with. regard to such comparatively small variations as are met with when using different grades of petrol and benzol. The seat of the trouble lies in the faet that the mixing is inadequate, and temperature is not sufficiently studied; and without these two factors being taken into serious consideration, a homogeneous and dry gas will not be obtained. The consequen.ee of this is loss of power through condensation, unevenness in burning, and incomplete combustion. Many inventors before the war tried to produce a