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 chart of masked versus unmasked camshafts with different lift rockers.
| Identifier | ExFiles\Box 13\2\ 02-page153 | |
| Date | 29th October 1931 guessed | |
| RM{William Robotham - Chief Engineer} P 30. COMPARISON OF 108° MASKED CAMSHAFT AND 114° E82448 UNMASKED CAMSHAFT OPEN EX. C/R 4.7 HIGH LIFT ROCKERS TWIN CARBS 1.4 CHOKES MASKED CAMSHAFT INLET LIFT .547 EXHAUST .469 B.H.P. R.P.M. INDUCTION DEPN. INS. HG. Diagram C: EX, IN, .020 CLCE, 22.75, 52, 49 Diagram A: EX, IN, HIGH LIFT ROCKERS .020 CLCE, 20, 4, 18.6, 41, 43.8, 67.8 Diagram B: EX, IN, HIGH LIFT ROCKERS .020 CLCE, 1.5, 12, 25.5, 46.0, 38.5, 62.5 Other Text: 114° SHAFT E.82448 VALVE LIFT INCR TO .525 Graph Curves: A, B, C | ||