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 power tests of an 8.1 Litre Phantom engine with various sized inlet valves.
| Identifier | ExFiles\Box 92\2\ scan0167 | |
| Date | 8th September 1933 | |
| H.S. 1147 8.1 LITRE PHANTOM POWER TESTS (P.II N° 27.) COMPARISON BETWEEN VARIOUS SIZED INLET VALVES (STANDARD EXHAUST) 2-1 1/8 S.U. CARBS - STD. CAMSHAFT (F.82448) - COMP RATIO 5.5:1 R.R. LEAD BRONZE BEARINGS + OPEN EXHAUST STD SPRINGS HS{Lord Ernest Hives - Chair} 664/5 DOUBLE TAPER VALVE SPRINGS ① LARGE INLET VALVES (F.83904) (2.000 THROAT) TULIP LIGHTENED TO (LEC.3579) STEM DRILLED TO (EX.12011) NEW WEIGHT 5.32 OZS ORIGINAL WEIGHT 6.53 OZS ② STANDARD INLET VALVES (F.82458) (1.9 THROAT) ③ INLET VALVES SAME AS EXHAUST (E.83700) (1.9 THROAT) N° ① AND ② CURVES ARE AN AVERAGE OF SEVERAL TESTS. B.H.P. MEP (LBS/□") R.P.M. TIMING WITH .020 CLCE TDC E.C. 4° I.O. 1° I.C. 51° E.O. 51° D.P.B 8.9.33 | ||