146 ALCOHOL FUELS. 



difficulties of starting a touring car with, say, 1501bs. compression 

 would be great and would require a compression relief gear. Then 

 again with throttle control there would be very little flexibility. 

 Every motorist knows that flexibility is one of the chief aims of 

 every designer of touring car engines, so I do not think that 

 engines with a compression much higher than at present will be 

 adopted. 



Then, again, if any of the mixtures of alcohol and other sub- 

 stances added to increase the vapour pressures were subjected to 

 much higher compression, pre-ignition would occur. 



In a stationary engine with alcohol alone a compression of 

 2001bs. per square inch could be adopted. This with a hit and 

 miss governor would probably be a good deal more economical 

 than a petrol engine, and would very nearly approach the Diesel 

 engine in thermal efficiency. 



In my opinion the carburetter of the petrol engine leaves 

 much to be desired if an alcohol fuel is to be used, and that if 

 alcohol alone is to be used a new design will be necessary. 



At the present time alcohol with different mixtures serves for 

 adaption to the present type of petrol car, and for some time to. 

 come will carry us over the transition stage, but in the end I feel 

 sure that alcohol alone, denatured of course to render it undrink- 

 able, will come out on top, as none of the substances added increase 

 its thermal efficiency to anything like the extra cost that they 

 entail. At the same time as before mentioned alcohol mixtures 

 will tide over the present, but will be discarded when suitable car- 

 buretters are fitted, and a plentiful supply of alcohol obtainable 

 everywhere. 



I think that with a suitable carburetter alcohol would give 

 very much better results than any of the mixtures, and the present 

 carburetter. 



The most suitable one would have to break up the alcohol' 

 into a spray and be fed with air at a temperature just high enough 

 to vaporize it. The proportions between fuel and air should be s 

 nearly constant at all speeds. For the general public a fixed jet 

 should be fitted. Alcohol having such a much wider explosive 

 range than petrol, a big waste of fuel can take place without the 

 driver being aware that his mixture is much too rich. I am 

 frequently told of cars pulling splendidly on Natalite, but the- 

 consumption is excessive. In almost every case of- this sort the 

 carburetter has a variable jet which is too much open. 



It would be an advantage to have the vaporizer heated up to> 

 facilitate starting. This could easily be done by an electric resist- 

 ance, as is the case, I believe, with some of the paraffin carburetters. 

 It is this difficulty in starting with alcohol alone that has to be- 

 overcome, and until there are plentiful supplies of denatured 

 alcohol of good quality to be obtained in every village sufficient 

 attention will not be paid to overcoming the difficulty. 



