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 B.M.E.P. curves for a Phantom II engine with standard versus 'R Type' camshafts.
| Identifier | ExFiles\Box 92\2\ scan0121 | |
| Date | 3rd June 1931 | |
| CURVE 1A PH.II B.M.E.P. CURVES OPEN EXHAUST 4.6:1 COMP. RATIO A.{Mr Adams} TWIN CARBS 1.3 DIA: CHOKES. (STD COMP. RATIO) (R TYPE 110° CAMSHAFT) B. " " " " " ( " " " ) (STD: " " ) R.W.S. 3-6-31 | ||