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).
Electrical quantities and starting torque for the 20 HP starting motor.
| Identifier | WestWitteringFiles\C\May1919\ Scan5 | |
| Date | 7th May 1919 | |
| To EFC. from E.{Mr Elliott - Chief Engineer} Copy to OJ. " " BN.{W.O. Bentley / Mr Barrington} " " DA.{Bernard Day - Chassis Design} " " EH. ORIGINAL 3 E5/G5/5/19. D RECEIVED 7 MAY 1919 X.3534 RE 20 H.P. STARTING MOTOR. In getting out the electrical quantities for the 20 H.P. starter motor, would you kindly note that the speed of the motor is supposed to be 3,000 revs. per minute when starting the engine, and the overall reduction on the gearing is 48 to 1. We took the starting torque for the 20 H.P. engine to be 450 lbs. inches at the crankshaft; this figure being pro rata with the 40/50 H.P. chassis at 900 lbs. inches, the basis of comparison being the relative displacement of the engines. E.{Mr Elliott - Chief Engineer} | ||