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).
Performance comparison graph between a 112° masked camshaft and a 114° unmasked camshaft.
| Identifier | Morton\M19\ img272 | |
| Date | 29th October 1931 guessed | |
| RM.{William Robotham - Chief Engineer}P.31. COMPARISON OF 112° MASKED CAMSHAFT AND 114° UNMASKED CAMSHAFT. OPEN EX. C R 4.7 HIGH LIFT ROCKERS. TWIN CARBS 1.4 CHOKES. MASKED SHAFT. INLET LIFT .547 EXHAUST LIFT .469. R.P.M. IND DEPN INS HG. B.M.E.P. A.{Mr Adams} B. C. Left Circle: HIGH LIFT ROCKERS .020 CLCE. EX. IN. A.{Mr Adams} 68. 44. 49. 21. 3. 11.2. Top Circle: 114° SHAFT E82448. VALVE LIFT INCREASED TO .525. EX. IN. C. 52. 49. 22. 7.5. Right Circle: HIGH LIFT ROCKERS .020 CLCE. EX. IN. B. 60.3. 36.3. 54.4. 29. 5°. 4°. | ||