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).
The 10,000-mile test of the 19-EX car, focusing on its new semi-expanding carburetter and performance.
| Identifier | ExFiles\Box 19\1\ Scan216 | |
| Date | 16th August 1932 | |
| 87120 To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} By.{R.W. Bailey - Chief Engineer} c. to Hdy.{William Hardy} PHANTOM II. X7080 19-EX. Car has now returned after 10,000 miles test in France. This car has been running principally in order to enable improvement to be made to the Continental Phantom II. The necessity for this is well realised. Last winter sales were promised that an improved Continental P.II would be available for sale in the spring of this year. The chief alteration on 19-EX. car is the R.R. semi-expanding carburetter. The first point to note with this carburetter is that the average petrol consumption in France was 9.3 m.p.g. (this car had 7 1/2% higher axle ratio and 1/4 ratio higher compression). The last 10,000 miles which was run out there on 25-EX. car averaged 10.9 m.p.g. We are conducting some consumption tests over average roads but we think it must be accepted that at present with this new carburetter we use more petrol than the old one with the same average speed. We do not consider the metering of the new carb. at present is as good as it might be but we are working on this. We have also got to accept with the new carburetter that we shall not have the same degree of mixture control. Another point which arises on the carburetter is the starting. On this carburetter we rely on the throttle edge for starting and find it is essential in order to get a reliable start we should have the throttle stop and it is also better to do without the governor so that the hand control lever is connected direct to the throttle. 19-EX. car was run without the governor. Although the carburetter has behaved reasonably well it should be realised that so far we have had very little experience with this under winter conditions. We know that we had considerable difficulty in making the present carburetter satisfy U.S.A. winter conditions both for starting and running. We have to take a certain risk in throwing away the present carburetter which has had about 25 years development work on it. The P.II however, is getting so far behind on performance that we must make a move. The carburetters of this type which we have so far been running are too small for maximum power. When we produce any of these carburetters it is proposed that we should produce them in the larger size. We expect to have one of these carburetters completed in a few weeks. | ||