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).
Data from the National Physical Laboratory on torque and horsepower for a 6-Cylinder 16 HP engine at 0°C.
| Identifier | ExFiles\Box 145\1\ scan0122 | |
| Date | 1st January 1933 | |
| TABLE 1 TORQUE IN LB/FT REQUIRED TO TURN ENGINE AT 0°C N.P.L. ENG. DEPT. TEST MARK | OIL | VISCOSITY AT 25°C CENTIPOISES | SPEED IN REVOLUTIONS PER MINUTE -|-|-| 0 | 30 | 60 | 75 | 90 | 120 G.M.S. 1. | A | 246 | 11.3 | 26.5 | 28.4 | 28.9 | 29.3 | 29.9 G.M.S. 2. | "A.F." | 350 | 10.5 | 30.1 | 33.2 | 34.4 | 35.6 | 38.0 G.M.S. 3. | "B.B" | 456 | 12.0 | 33.1 | 38.1 | 39.8 | 41.2 | 44.2 G.M.S. 4. | "D" | 580 | 8.0 | 36.8 | 44.0 | 46.0 | 47.7 | 50.7 IT IS CLEAR FROM THESE RESULTS THAT THE BREAK-AWAY TORQUE IS INDEPENDENT OF THE VISCOSITY ON THE ASSUMPTION THAT THE VISCOSITIES AT 0°C ARE IN THE SAME ORDER AS THOSE AT 25°C. AS THE SPEED INCREASES, THE TORQUE APPEARS TO BE DETERMINED LARGELY BY THE VISCOSITY ON THE SAME ASSUMPTION. TABLE 2 - HORSE-POWER REQUIRED TO MOTOR ENGINE N.P.L. ENG. DEPT. TEST MARK | OIL | SPEED IN REVOLUTIONS PER MINUTE -|-|-| 30 | 60 | 75 | 90 | 120 G.M.S. 1. | A | 0.15 | 0.32 | 0.41 | 0.50 | 0.68 G.M.S. 2. | "A.F" | 0.17 | 0.32 | 0.49 | 0.61 | 0.87 G.M.S. 3. | "B.B" | 0.19 | 0.44 | 0.57 | 0.71 | 1.01 G.M.S. 4. | D | 0.21 | 0.50 | 0.66 | 0.82 | 1.16 GRAPH 1 (Left): AXES: TORQUE - LBS. FT. vs{J. Vickers} REVS. PER MINUTE. LINES: MOBILOIL "D", MOBILOIL "B.B", MOBILOIL "A.F", MOBILOIL "A" NOTES: BREAK-AWAY TORQUE, STARTING TESTS AT 0°C (32°F), 6-CYL. STANDARD 16 H.P., NATIONAL PHYSICAL LABORATORY. GRAPH 2 (Right): AXES: BRAKE HORSE POWER. vs{J. Vickers} REVS. PER MINUTE. LINES: MOBILOIL "D", MOBILOIL "B.B", MOBILOIL "A.F", MOBILOIL "A" NOTES: STARTING TESTS AT 0°C. (32°F.{Mr Friese}), 6 CYL. STANDARD 16 H.P., NATIONAL PHYSICAL LABORATORY, 1933. | ||