From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Performance issues of a new carburettor, including poor fuel consumption and engine flooding.
| Identifier | ExFiles\Box 102\1\ scan0284 | |
| Date | 17th May 1935 | |
| Wor.{Arthur Wormald - General Works Manager} -2- C3/C17.5.35 faster than the old one on pick-up, the customer not always appreciating that the car generally has gone up in weight, and seldom requiring the very slight improvement at high speed. We recently took the petrol consumption of private owners, compiled from 100 Inspection Reports, and the average over the 100 was just over 17 miles to the gallon with the old carburettor. It appears that customers are not able to get more than 14 m.p.g. with the new carburettor, and many get less even on a decent straight run. We have taken out further figures which show that: Over 35 recent reports of old carburettors the average is 18.25 mpg. " 21 " " " new " " 13.85 " Difference = 4.4 m.p.g. or 24.1%. We have also taken from the customer a point that has always been much appreciated, namely the ability to weaken the mixture and get improved petrol consumption when not requiring full power from the engine. It is, however, one little point that is very much appreciated by a large number of owners and drivers. We now have this third and really most important trouble, namely the flooding, to such an extent as to cause the car to stop in traffic, to the humiliation of the owner and driver. From the customers point of view apparently the only advantages are the cure of the spitting back and possibly the necessity for cleaning the air valve, although I believe one can overcome this latter on the old carburettor with the new air valve designed a little time ago. This I think you will agree is most disturbing and I should be glad if you would have the matter very carefully investigated. You will, of course, have seen reports as to what has been found to be the cause of the various stoppages. Three recent cases we have in mind are Sir George Sutton (2 carburettors,) Major Monro, and Dr.Beaumont. C. PS. Since writing the above I have had experience of this flooding myself. This morning, coming through Hyde Park, I was stopped by a Point Policeman and the engine stopped | ||