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).
Performance comparison of Bijur and Westinghouse starter motors, including torque, speed, and current consumption.
| Identifier | ExFiles\Box 23\2\ Scan048 | |
| Date | 27th April 1920 | |
| Contd. -3- Oyl - M27.4.20. BIJUR. Assumed Engine Torque 45 ft. lbs. Gear ratio. Starter Torque Ft. lbs. Speed R.P.M. Starter Engine. Starter. Amperes. 12 to 1 4 1900 158 135 15 to 1 3.2 2080 139 115 23.3 to 1 2.05 2400 103 90 WESTINGHOUSE Assumed Engine Torque 45 ft. lbs. Gear ratio. R.P.M. of Starter Cranking R.P.M. of engine Load in amperes. Lock Torque 12:1 2400 190 220 250 ft.lbs. 15:1 2675 165 190 315 " " 23.3:1 3160 125 170 490 " " The maximum H.P. of Bijur is about 2.4 at 750 R.P.M. and 400 amps. discharge rate. It turns the engine at about 100 R.P.M. and consumes about 100 amps. when turning the engine at ordinary temperatures of about 62 degrees F.{Mr Friese} The stalling torque depends somewhat on the battery resistance but is probably about 25ft. lbs. From a rough test recently made at the service station, in trying out Exide Batteries:- Our own starter takes -------------- 75 amps. when cranking the engine at --------- 66 R.P.M. at a temperature of about ---------- 44 degrees F.{Mr Friese} The current consumed was about -------- 70 amps. and the speed ---------------------- 80 R.P.M. at ------------------------------- 63 degrees F.{Mr Friese} It seems, therefore, that, at ordinary temperatures, the Bijur motor will turn the engine at 25% higher speed with a current consumption about 50% greater than our own starter, if used with our present gear ratio: or will turn the engine at twice the speed, using twice the current, if used with a ratio | ||