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).
Technical summary comparing Bentley and Wraith camshafts, exhaust systems, and carburettors.
| Identifier | ExFiles\Box 108\2\ scan0196 | |
| Date | 13th January 1939 | |
| -2- The Bentley camshaft is not as good as the Wraith for idling, but it is not bad in this respect, and maybe with the raised engine mounting we should not notice much difference. We think it is well worth trying a Bentley camshaft in a Wraith. These tests have been done with a Bentley II exhaust system, and, of course, the losses on the Wraith system are even greater than those of the Bentley. However, the new exhaust system developed by Whyman approaches Bentley efficiency. Experiments are still being continued with the Duplex Stromberg carburetter which may enable us to approach results obtained with the two carburetters. Summarising the position, these curves again prove that there are numerous things we can do to improve the Wraith power output, and the results obtained on the Humber 'Super Snipe' indicate that we ought to be able to increase this output without making the car unpleasant. If, as a result of our experiments we find that we have increased performance at the expense of silence or smoothness we shall not consider that we have made any progress. Rm.{William Robotham - Chief Engineer} | ||