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 108° masked camshaft and a 114° unmasked camshaft.
| Identifier | Morton\M19\ img271 | |
| 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.47 HIGH LIFT ROCKERS TWIN CARBS 1.4 CHOKES MASKED CAMSHAFT INLET LIFT .547 EXHAUST .469 Axes: B.H.P. (vertical left, 80-160) R.P.M. (horizontal bottom, 500-3500) INDUCTION DEPN INS HG (vertical right, 2-4) B.M.E.P. (vertical right, 60-110) Graph Keys: A, B, C Diagram C (Top Left): 114° SHAFT E82448 VALVE LIFT INCR. TO .525 C EX, IN .020 CLCE Timings: 22 7.5, 52, 49 Diagram A (Bottom Left): HIGH LIFT ROCKERS .020 CLCE A EX, IN Timings: 20 4 18.6, 67.8, 43.8, 41 Diagram B (Bottom Right): HIGH LIFT ROCKERS .020 CLCE B EX, IN Timings: 1.5 12, 25.5, 62.5, 38.5, 46.0 | ||