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).
Engine development strategy and the relative merits of different fuel delivery systems.
| Identifier | ExFiles\Box 179b\1\ img043 | |
| Date | 3rd September 1932 guessed | |
| (2) At the moment I think that HS.{Lord Ernest Hives - Chair} is in agreement with me that it would be better to move to J.{Mr Johnson W.M.} 3. complete car, rather than take 2 steps to J.{Mr Johnson W.M.} 1., and then J.{Mr Johnson W.M.} 3. You will remember that I pressed very hard for Derby to be interested in J.{Mr Johnson W.M.} 1. head when we brought it out, but the time has now passed when this move would be advantageous, and I favour now the greater move to the J.{Mr Johnson W.M.} 3., especially as we shall be having Peregrine available, and it is time the 25HP. stepped up into a somewhat larger car, where it will carry the necessary bodies and give a better performance without losing so much of the RR. qualities. The car you took to France I had intended should have been fitted up with the best we could make of our old standard carburetters, which would still be a good thing to do with it until such time as the RR. semi-expanding carburetter is ready. The mechanically driven petrol pumps have been considerably more trouble than was anticipated by me or anyone else, though they were thought to be simpler and less costly than the autovac, which has several undesirable features, viz: (1) It does not feed at full throttle, therefore would fail on a long straight road, even if it were not a hill, unless the throttle is occasionally partly closed. (2) It affects the slow speed running of the engine. We avoided both these faults by the extra complication of a vacuum pump on P. 2., and 25HP. has a large autovac tank to reduce the risk of (1). Naturally I do not wish to adopt a mechanically driven pump as standard until it has proved itself at least equally reliable as the autovac, which has been more trustworthy than an examination of its parts would suggest. R.{Sir Henry Royce} | ||