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).
Comparison of efficiencies for STD. 40/50 RR. and E.A.C.1 engines with valve timing diagram.
| Identifier | ExFiles\Box 72\4\ scan0330 | |
| Date | 14th November 1923 guessed | |
| PAGE 5. COMPARISON OF EFFICIENCIES OF STD. 40/50 RR. & E.A.C.1 WITH THE AIR STANDARD EFFCY: 40/50 RR. Comp: ratio = 3.99 E.A.C.1 Comp: ratio = 4.6 'Air standard' = 1 - 1/r^(γ-1) | R.P.M. | Indicated Thermal Efficiency % | Indicated thermal efficiency X 100 / standard efficiency % | |---|---|---| | | 40/50 RR. | E.A.C.1. | 40/50 RR. | E.A.C.1. | | 500 | 21.34 | ---- | 50.25 | ---- | | 600 | ---- | 27.33 | ---- | 59.8 | | 750 | 21.24 | 27.56 | 50.0 | 60.4 | | 1000 | 23.69 | 27.31 | 55.8 | 59.8 | | 1250 | 24.00 | 30.05 | 56.5 | 65.75 | | 1500 | 24.74 | 29.49 | 58.2 | 64.6 | | 1750 | 25.50 | 29.26 | 60.0 | 64.0 | | 2000 | 25.10 | 29.52 | 59.1 | 64.7 | AIR STANDARD EFFICIENCY. | 40/50 RR. | E.A.C.1. | | r = 3.99 | r = 4.6 | | .4251 | .4569 | VALVE TIMING USED. IN.OP. 2° EX.CLO. 4° 37° 48° EX.OP IN.CLO. Timing taken with .010" tappet clearance. 110° Camshaft. | ||