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).
Notes on Delco high-speed coils, starting motors, dynamos, and frame design.
| Identifier | ExFiles\Box 173\1\ img283 | |
| Date | 24th February 1934 | |
| -5- He/Rm.{William Robotham - Chief Engineer}5/24.2.34. Cont'd.{John DeLooze - Company Secretary} Delco High Speed Coil. They know nothing of this, that is the one with the small vibrator. Starting. On the 12 & 16 cylinders they use 20-1 starting motor ration. The reduction is built into the motor and gives them no trouble for silence. Their main trouble is with the flywheel ring. They use a solenoid remote controlled starter switch, knob on dashboard. The starter motor is 4 15/16" diameter and gives 42 . lbs inches torque when stalled then taking 600 amps at 3 volts. (This torque seems big being 2x ours). Dynamos. They are using straight shunt wound dynamos with current regulation. I enclose wiring diagram and output. They use direct air cooling on the dynamo a thing we have been frightened of for so long. They do not have any serious trouble even in arid regions. They expected excessive brush wear. On the 12 & 16 the dynamos run at 1.4 engine speed, the engines run up to 4250 (run 1 hrs. endurance at this speed) and no trouble is experienced with excessive sparking and brush wear. Delco's would like them to run faster but their chain drive limits the speed. I must call at Delcoa to get first hand information of all this and also the parts you want. Shall bring a starter motor back as well as the ignition. Independent Suspension. Cross in the Frame. Cy. thinks that they will get rid of this next year. He says it only stiffens up the chassis where it is already plenty stiff enough. However one must remember that they have stiff all steel bodies. | ||