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 for a 10 EX aluminium engine with a 4.95-1 compression ratio, plotting BHP against RPM and MPH.
| Identifier | ExFiles\Box 29\3\ Scan167 | |
| Date | 7th 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. 16 TOOTH M.P.H. 17 TOOTH M.P.H. Graph Curves: B.H.P. C.O. OPEN ROAD WHEEL H.P. C.O. OPEN Table 1: 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 Table 2: AVERAGE PRODUCTION FIGURE. % LOSS TO ROAD WHEELS. 2750 38% 2500 28% 2250 22% 2000 22% 1500 20% 500 15% Table 3: AS ABOVE LOSS AT VARIOUS ROAD SPEEDS M.P.H. % LOSS 80 35% 70 27% 60 22.5% Table 4: 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% Stamp: ROLLS-ROYCE LIMITED SAINT ROOK. 7 SEP 1927 DERBY | ||