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).
Graph comparing power output (BHP and BMEP) for an Aluminium Phantom engine with large versus small diameter valves.
| Identifier | ExFiles\Box 42\4\ Scan060 | |
| Date | 6th June 1924 | |
| SHEET 3. BRAKE HORSE POWER. BMEP (LBS. PER SQ. IN.). R.P.M. OF ENGINE. LARGE VALVES. B.H.P. " B.M.E.P. SMALL VALVES. B.H.P. " B.M.E.P. ALUM. PHANTOM POWER COMPARISON. FOR. 1.600 DIA. & 1.750 DIA. VALVES. COMP. RATIO = 4.60 : 1. CORRECTED N.T.P. 6/6/24 | ||