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 results for a 40/50 HP test engine, showing thermal efficiency, power, and heat balance under high compression.
| Identifier | WestWitteringFiles\K\September1923\ Scan24 | |
| Date | 12th July 1923 guessed | |
| SHEET 1. HIGH COMPRESSION. THERMAL EFFICIENCY, POWER ETC. OF 40/50 HP. RR TEST ENGINE. COMPRESSION RATIO 4.4. FUEL 'SHELL' NO.2. S.G. .752. CAL.{Mr Calvert}VALUE (LOWER) 19,000 B.Th.U's/LB. First Table: R.P.M. | Fuel pts. hr. | Pts. HP. hr. | B.H.P. | I.H.P. | HP. to drive motor. | Temp. Jacket water. oC Inlet.Outlet. | Lbs. water min. | B.Th.U's. to jacket water. | Mech.Effcy. 500 | 18 | .76 | 23.6 | 27.6 | 4 | 60 | 74 | 68.05 | 1714.8 | 85.5% 750 | 27 | .76 | 35.3 | 40.8 | 5.5 | 63 | 75 | 92.34 | 1994.5 | 86.5% 1000 | 34 | .72 | 47.3 | 55.3 | 8 | 66 | 77 | 120.5 | 2385.9 | 85.6% 1250 | 44 | .73 | 59.6 | 71.1 | 11.5 | 66.5 | 77.5 | 149.1 | 2952.2 | 83.8% 1500 | 49 | .69 | 70.3 | 85.8 | 15.5 | 70 | 81 | 180.4 | 3571.9 | 82.0% 1750 | 56.5 | .74 | 76.2 | 96.2 | 20 | 72 | 81 | 220.9 | 3578.6 | 79.3 2000 | 59 | .71 | 82.5 | 108.5 | 26 | 73.5 | 82 | 255 | 3901.5 | 76.0 HEAT BALANCE. Second Table: R.P.M. | 500 | 1000 | 1500 | 2000 Thermal equt. work done. | 1000 | 2005 | 2983 | 3499 Loss to engine friction. | 169 | 339 | 636 | 1103 Heat loss to jackets. | 1715 | 2386 | 3572 | 3901 Loss through exhaust radiation etc. (By difference) | 2774 | 5400 | 7399 | 9067 Heat supplied. | 5508 | 10130 | 14590 | 17570 SHEET 1. CONTD:- | ||