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 of an aluminum engine with a long duration camshaft and turbulent head, showing BHP vs RPM and various power loss/gain calculations.
| Identifier | ExFiles\Box 69\4\ scan0343 | |
| Date | 7th September 1927 | |
| 10 EX. ALUM ENGINE COMP RAT. 4.95-1 STANDARD INDUCTION AND EXHAUST LONG DURATION CAMSHAFT TURBULENT HEAD GRAPH: Y-Axis: B.H.P. X-Axis: ENGINE R.P.M. Top X-Axis Scale: 17 TOOTH M.P.H. & 16 TOOTH M.P.H. Bottom X-Axis Scale: 16 TOOTH M.P.H. Curve 1: B.H.P. C/O OPEN Curve 2: 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: OFFICE LIMITED ROOM 7 SEP 1927 | ||