In an article entitled “Rumblings” in your December issue there is a statement that the “new-found speed” of Kelly’s Alta is due to the fitting of a Weber carburetter. I am sorry to have to contradict this statement in its entirety: in point of fact, Kelly’s car has not any “new-found speed” but has probably returned to something approaching its original speed.
A Weber carburetter was tried in the North of Ireland, but was not taken out of the country by Kelly, and as you yourself are fully aware, the mere fitting of a carburetter is extremely unlikely to produce more speed on any vehicle, since the carburetter’s main function is to adequately mix fuel and air in something like the correct proportions, and in sufficient quantity for the engine to consume.
What actually happened was that due to corrosion during the winter, and general stoppage in the fuel system, Kelly filed and otherwise modified the needles originally fitted by us to the two SU carburetters. Having found that this was approaching the problem from the wrong end, he asked my advice, and I told him to first of all get the whole system thoroughly cleaned, and fit a new fuel pump to replace one badly corroded. Having done this, the carburation was, as one would expect, all over the place and excessively rich, and this was the original trouble at Silverstone. Not having the car available here, I asked Kelly to send me his carburetters complete, and I then put them on the test bench on another two-stage engine, and tuned them correctly, returning them to him in time for the Winfield Races in which he competed and in which the “new-found speed” was alleged to have been found.
I am not claiming any recognition for myself, or for the firm for what is after all an ordinary piece of servicing for a racing car, but I do feel that the SU Company are entitled to this explanation.
In passing, I have carried out all the bench test work on carburation with both the Webers and the SU on the Alta engines as fitted to the HWM, and I can state, without fear of contradiction, that in all circumstances and conditions the SU carburetters can produce at least as good results as the Webers, and are in every way a very good instrument indeed.
I am, Yours, etc.,
Geoffrey Taylor. Surbiton.
[The fact remains that, in this country HWM and Aston-Martin have changed to Webers.—Ed.]