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).
Phantom camshaft experiments comparing standard vs long duration camshafts on engine performance and valve timing.
| Identifier | ExFiles\Box 69\4\ scan0372 | |
| Date | 21th January 1927 | |
| PHANTOM CAMSHAFT EXPTS. 4:1 TO 1 COMPN RATIO WITH SHORT EXH. PIPES TO EACH PORT. TWO R.R.C.H CARBURETTERS. STANDARD CAMSHAFT. E.C. 2°, I.O. 14°, I.C. 30°, E.O. 34°. LONG DURATION INLET AND EXHAUST. E.C. 10°, I.O. 5°, I.C. 52°, E.O. 54°. LONG DURATION INLET STD. EXHAUST. E.C. 10°, I.O. 5°, I.C. 52°, E.O. 42½°. ALL TIMING DIAGMS WITH .020 TAPPET CLCE. B.H.P. ENGINE R.P.M. STANDARD. CAMSHAFT. LONG DURATION INLET STANDARD EXHAUST. LONG DURATION INLET AND EXHAUST. No5. MAX. POWER IS REACHED AT A HIGHER SPEED WITH LONG DURATION CAMSHAFT. ael | ||