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).
Proposal for experiments to increase the power output of the Phantom II engine.
| Identifier | ExFiles\Box 65a\3\ scan0279 | |
| Date | 7th April 1931 | |
| To L.H.S.{Lord Herbert Scott - Chair} from Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey} c. Hs.{Lord Ernest Hives - Chair} c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} x777° Hs{Lord Ernest Hives - Chair}/Lov{Mr Lovesey}2/ADL 7.4.31. x777/ INCREASING POWER OUTPUT ON PHANTOM II. We propose to carry out the following experiments with the object of increasing the high speed power output of Phantom II. At present our power curves peak about 2500 R.P.M. and at maximum road speed of car the R.P.M. is in the neighbourhood of 3250 R.P.M. We want to aim at extending the power peak up to at least this figure and cater for running up to maximum speeds of 3500 R.P.M. In attaining this increased high speed performance we do not want to sacrifice any of the lower speed performance recently obtained with the twin choke carburetter. The demand is therefore for a twin or double carburetters although induction system modifications may be necessary to cater for the higher speeds. The following programme shews the general lines upon which we should work. (1) Compression Ratio. We wish to use 5/1 ratio with the cast iron large valve head. We should therefore see to what extent we want to reduce the depth of the combustion chamber to get 5/1 ratio. We can then see if this amount can be skimmed off the head. If not sufficient we can remove some from the head of the cylinder block and top of piston. | ||