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).
Outlining proposed modifications for Phantom power development to increase performance.
| Identifier | ExFiles\Box 113\2\ scan0129 | |
| Date | 28th November 1927 | |
| Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to BJ. Wor.{Arthur Wormald - General Works Manager} C. c. to PN.{Mr Northey} CWB. SG.{Arthur F. Sidgreaves - MD} 41725 R2/M28.11.27. X.8830 X.172 X.8060 X.877 X.8771 PHANTOM - POWER DEVELOPMENT. For increased performance of acceleration, hills, and speed we are arranging for modifications as follow, to advance the power for sports and other chassis. Taking the present 4.1 to 1 comp. ratio under silent road conditions to give a maximum of - Cutout open plus 10% 105 HP. } Maintaining double exhausts & two 115 HP. } groups of threes. Comp. ratio plus 10% 126 HP. } This is possible with turbulent } head to reduce detonations and } flexible mounting to reduce feeling } of torque reaction. Carb. plus 8% lower depression) 4" to 1/2". This is possible with 136 HP. ) straight through carburetters. Valve area plus 18% = 10% gain) Head 2" - large light inlet } Slight economies and larger valve 1.9. 149 B.HP } inlet than exhaust. Head 1.75" slightly smaller } exhaust 1 5/8. } Valve timing long 155 B.HP } Forego if necessary small percen- duration plus 4% } tage of low speed torque - for the } loss we gain in less detonations } and harshness. At speed of 2750 r.p.m. hope for 100 M.E.P. ) Should equal 157 B.HP. The whole of these are some distance away but many should be possible on EAC.14., and all on EAC.10. In the meantime every effort should be made to reduce weight and windage of bodies etc. - lower and lighter, R.{Sir Henry Royce} | ||