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 17 slot armature.
| Identifier | ExFiles\Box 34\3\ Scan145 | |
| Date | 25th March 1918 | |
| X.2642B X.2642B - BRAKE TEST OF R.R. SELF STARTERMOTOR (17 SLOT ARMATURE) Speed R.P.M. | Torque (lb-inches) | Amps. | Volts. | B.H.P. | E.H.P. | Efficiency. --- | --- | --- | --- | --- | --- | --- 200 | 103.0 | 195.5 | 9.27 | .327 | 2.427 | .135 400 | 83.3 | 166.0 | 9.50 | .512 | 2.113 | .242 600 | 68.5 | 144.0 | 9.70 | .652 | 1.873 | .348 800 | 57.0 | 128.0 | 9.86 | .723 | 1.693 | .427 1000 | 47.0 | 113.75 | 10.07 | .745 | 1.536 | .485 1200 | 38.2 | 101.25 | 10.26 | .727 | 1.393 | .522 1400 | 30.4 | 90.0 | 10.44 | .674 | 1.260 | .535 1800 | 18.4 | 70.5 | 10.72 | .525 | 1.014 | .518 2200 | 11.2 | 55.5 | 10.91 | .391 | .8125 | .481 2600 | 6.3 | 45.0 | 11.06 | .259 | .668 | .388 3000 | 2.6 | 37.0 | 11.22 | .124 | .556 | .223 Handwritten notes: { Weight of pan + portion of rope - 13 ozs. { Zero reading of spring balance - 3 1/2 lbs. (Lever ratio 13.85" : .53 | ||