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).
Test data on the thermal efficiency and power of the 40/50 test engine at low compression, including a heat balance analysis.
| Identifier | WestWitteringFiles\K\September1923\ Scan26 | |
| Date | 12th July 1923 guessed | |
| SHEET 2. LOW COMPRESSION (PRESENT STD.) THERMAL EFFICIENCY, POWER ETC. OF THE 40/50 RR. TEST ENGINE. COMPRESSION RATIO 3.9 - ENGINE CLEAN - FUEL 'SHELL' NO.2. S.G. .752. CAL.{Mr Calvert}VALUE (LOWER) 19,000 B.Th.U's/LB. [TABLE 1] R.P.M. | Fuel pts. hr. | Pts. HP. hr. | B.H.P. | I.H.P. | HP. req. drive motor. | Jacket water. °C Inlet.Outlet. | Lbs. water min. | B.Th.U's. min. to water. | Mech. effcy. 500 | 18.09 | 0.78 | 23.1 | | 4 | 57.75 | 80 | 41 | 1660 | 750 | 26.27 | 0.78 | 33.67 | | 5.5 | 58 | 78 | 62.5 | 2250 | 1000 | 32.14 | 0.706 | 45.42 | | 8 | 61 | 81 | 82.5 | 2970 | 1250 | 40.45 | 0.71 | 56.75 | | 11.5 | 64.5 | 81.5 | 103.5 | 3167 | 1500 | 46.75 | 0.70 | 66.25 | | 15.5 | 65 | 80 | 126 | 3402 | 1750 | 52.9 | 0.71 | 74.75 | | 20 | 66.5 | 80.5 | 150 | 3780 | 2000 | 58.53 | 0.75 | 77.29 | | 26 | 70.5 | 83 | 177 | 3982 | HEAT BALANCE. [TABLE 2] R.P.M. | 500 | 750 | 1000 | 1250 | 1500 | 1750 | 2000 Thermal equt. work done. | 980 | 1428 | 1927 | 2407 | 2809 | 3171 | 3278 Loss to engine friction. | 169 | 233 | 339 | 488 | 636 | 847 | 1103 Heat loss to jackets. | 1660 | 2250 | 2970 | 3167 | 3402 | 3780 | 3982 Ht. loss through exh. & radiation by difference. | 2577 | 3909 | 4332 | 5978 | 7073 | 7952 | 9067 Heat supplied. | 5386 | 7820 | 9568 | 12040 | 13920 | 15750 | 17430 | ||