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).
Brake test results for a self-starter motor with a 45 slot armature.
| Identifier | ExFiles\Box 34\3\ Scan137 | |
| Date | 5th March 1918 | |
| X. 2642 5.3.18. X.2642B BRAKE TEST OF R.R. SELF STARTER MOTOR (with 45 slot armature) Load in Pan (lbs) | Spring Bal. Reading (lbs). | Speed. R.P.M. | Amps. | Volts. | Nett. Spring bal reading (lbs). | S (lbs). | T (lbs). | T-S (lbs). | Torque (lb.inches) | B.H.P. | E.H.P. | Efficiency ---|---|---|---|---|---|---|---|---|---|---|---|--- 20. | 8½ | 495 | x 168 | 9.425 | 5 | 2.65 | 20.81 | 18.16 | 90.8 | .713 | 2.120 | .336 18 | 8 | 590 | 155.5 | 9.525 | 4½ | 2.39 | 18.81 | 16.42 | 82.1 | .768 | 1.985 | .387 16 | 7¾ | 690 | x 142.5 | 9.625 | 4¼ | 2.25 | 16.81 | 14.56 | 72.8 | .797 | 1.837 | .433 14 | 7¼ | 800 | 129.5 | 9.75 | 4 | 2.12 | 14.81 | 12.69 | 63.45 | .8045 | 1.691 | .4755 12 | 7 | 935 | x 116.5 | 9.95 | 3½ | 1.85 | 12.81 | 10.96 | 54.8 | .813 | 1.552 | .5235 10 | 6½ | 1085 | 103.5 | 10.15 | 3 | 1.59 | 10.81 | 9.22 | 46.1 | .793 | 1.407 | .563 8 | 6 | 1250 | x 90.5 | 10.35 | 2½ | 1.32 | 8.81 | 7.49 | 37.45 | .7425 | 1.256 | .591 6 | 5½ | 1465 | 77. | 10.55 | 2¼ | 1.12 | 6.81 | 5.69 | 28.45 | .661 | 1.089 | .606 4 | 4¾ | 1735 | x 63 | 10.775 | 1¼ | .66 | 4.81 | 4.15 | 20.75 | .571 | .910 | .628 3 | 4½ | 1920 | 55 | 10.925 | 1 | .53 | 3.81 | 3.28 | 16.4 | .499 | .805 | .620 2 | 4¼ | 2155 | x 48 | 11.075 | ¾ | .40 | 2.81 | 2.41 | 12.05 | .412 | .7125 | .578 1 | 4 | 2475 | 40 | 11.20 | ½ | .26 | 1.81 | 1.55 | 7.75 | .304 | .600 | .506 0 | 3½ | 2905 | x 32.5 | 11.325 | 0 | 0 | .81 | .81 | 4.05 | .186 | .4925 | .378 | ||