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 curves of Brake Horsepower at the flywheel versus Road Speed for various engine and gear configurations.
| Identifier | ExFiles\Box 4\1\ 01-page004 | |
| Date | 20th September 1932 guessed | |
| POWER COMPARISONS - B.H.P AT FLYWHEEL AGAINST RPM (OPEN EXHAUST) Y-AXIS: B.H.P. (FLYWHEEL) X-AXIS: ROAD SPEED M.P.H GEAR RATIOS:- ① STD PII 60 M.P.H: 2215 R.P.M ② S.T.D. PII 60 M.P.H: 2315 R.P.M. ③ S.T.D. PII 60 M.P.H: 2315 R.P.M. ④ S.T.D. PII S.H.P 60 M.P.H: 3018 R.P.M. ⑤ 60 M.P.H: 2700 R.P.M. 100 M.P.H: 4500 R.P.M. ENGINE CONFIGURATIONS: ① STD PHANTOM II - 7668cc ② CONTINENTAL PII (RR SEMI EXP CARBS - R: 5.25:1) - 7668cc ③ CONTINENTAL PII (TWIN SU CARBS. R: 5.25:1) - 7668cc ④ 12 CYL. 3¼x4 - J1 ENGINE (TWIN SU CARBS R: 6.3:1) - 6252 cc (112° CAMSHAFT) ⑤ 12 CYL. 3.25x4.5 - J1 ENGINE (TWIN SU CARBS R: 6.3:1) - 7338 cc (112° CAMSHAFT R: 6.3:1) | ||