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).
Power test results comparing different sized inlet valves for an 8.1 litre Phantom engine.
| Identifier | ExFiles\Box 17\6\ Scan163 | |
| 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 7/8 S.U. CARBS. - STD. CAMSHAFT (F.{Mr Friese} 82448) - COMP. RATIO 5.5:1. R.R. LEAD BRONZE BEARINGS + OPEN EXHAUST. STD. SPRINGS ② STANDARD INLET VALVES (F.82458) (1 1/8 THROAT) ③ INLET VALVES SAME AS EXHAUST (F.83700) (1 1/8 THROAT) 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. H.S. 664/5. DOUBLE TAPER VALVE SPRINGS N° ① AND ② CURVES ARE AN AVERAGE OF SEVERAL TESTS. B.H.P. M.E.P. (LBS/□") R.P.M. TIMING WITH OZO CLCE TDC EC 4° IO 1° IC 51° EO 51° R.W.P. 8.9.33 | ||