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).
Increasing the horsepower and improving the performance of the 20 HP model.
| Identifier | ExFiles\Box 5\2\ 02-page252 | |
| Date | 22th April 1929 | |
| X8930 Hs.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} } from R.{Sir Henry Royce} SECRET. DA.{Bernard Day - Chassis Design} Ry. } (at Le CanadelHenry Royce's French residence) RL/M18.4.29. Rec'd at WN. 22.4.29. c. Lord Wargrave. LHS.{Lord Herbert Scott} Mr. Claremont. Wor.{Arthur Wormald - General Works Manager} Sg.{Arthur F. Sidgreaves - MD} Pn.{Mr Northey} EP.{G. Eric Platford - Chief Quality Engineer} 20 H.P. x 5770 x 5050 It is decided that we cannot keep the weight of our 20 HP. complete car down to that of the Chrysler and other 25 HP. cars, so that we must increase the size and HP. of the engine as soon as convenient. Naturally this has always been before us, but whatever we do it will never satisfy everyone because the more it is increased the greater the total weight will become until we get into the same position. But everyone believes that a 20 HP. equipment is not large enough for our second model, therefore it must be increased to 25 HP - i.e. .25" on the bore, and it may later have .5" on the stroke. This latter suggestion would mean a new engine, new crankshaft and connecting rods, and looks as though our reputation would be hopelessly lost before it was in the hands of the customers. One feels it is much easier to ask for, than to get, and also I am not sure how the rest of the chassis would stand the increase - clutch, gear box, back axle, seem none too large for the increase given below. It still therefore looks as though for the immediate production we must make the very best of our present engine and chassis for perhaps another 500 chassis, at least, by :- (1) Still doing all we can to keep down the body weights, and height, and width, but we must make them long enough for 6 seats when needed. We must continue to help coachbuilders for lighter body construction and accessories, (there is much hope in eight). My idea of 3" on the chassis is to avoid the short and ugly scuttles by having only the P. steering. It also keeps the roof down by the difference in the height of the seats. We must get this going quickly it is now nearly two years old. (2) We have already increased the engine maximum HP. by 20% at say 10% higher revs., so we can have 10% lower gear than in the present large wheel standard. We should then get at moderate speeds - 30/50 MPH. - the 20% increase in torque all in acceleration or hill climbing. (3) Mr. Elliott has made the discovery and valuable suggestion that we can increase the cyl. bore from 3" to 3.25" with the present engine, which is about 17%. This would give us another very definite move, and be sufficient with (1) and (2) to meet our present needs. contd. | ||