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 graph comparing BHP to Engine RPM for a 10 HP aluminum engine with a turbulent head and long duration camshaft.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 87 | |
| Date | 6th September 1927 | |
| 10 EX. ALUM ENGINE COMP. RAT. 4.95-1 STANDARD INDUCTION AND EXHAUST LONG DURATION CAMSHAFT TURBULENT HEAD. B.H.P. ENGINE R.P.M. 17 TOOTH M.P.H 16 TOOTH M.P.H B.H.P. C.O. OPEN ROAD WHEEL H.P. C.O. OPEN 17 TOOTH 90 M.P.H. 16 TOOTH 90 M.P.H. ROAD SPEED ENGINE REV. M.P.H. 16x52 17x52 80 2600 2450 70 2278 2140 60 1950 1835 50 1670 1580 40 1310 1228 30 978 920 20 653 613 AVERAGE PRODUCTION FIGURE % LOSS TO ROAD WHEELS. 2750 38% 2500 28% 2250 22% 2000 22% 1500 20% 500 15% AS ABOVE LOSS AT VARIOUS ROAD SPEEDS. M.P.H. % LOSS. 80 35% 70 27% 60 22.5% DIFFERENCE IN H.P AT ROAD WHEELS AVAILABLE. 16 & 17 TOOTH AXLE. M.P.H. % GAIN 17x52 90 10.5% 80 4.5% 70 2.% ROLLS-ROYCE, LIMITED PRINT ROOM, 6 SEP 1927 DERBY. | ||