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).
Secret memorandum discussing specifications for an electric starter and solutions for engine vibrations.
| Identifier | ExFiles\Box 64\1\ scan0172 | |
| Date | 14th March 1924 | |
| X9620 To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. to CJ. S E C R E T. E1/M14.3.24. ENGINE. X.9620 X.9550 re. ELECTRIC STARTER. X.9620 Please find attached a blue print of LeC.1348., shewing the quantities suggested for the starter actuator switch spring and the starter pinion spring. Briefly the former is shewn .375 wide by .010" (33 SWG) spring steel strip exerting a pressure of .5 lbs. on the contact points, and requiring an opening force from the armature of .25 lbs. rising to .4 lbs. The pinion spring it is proposed should have an initial load of 1.5 lbs. and consist of 16 turns of .048 (18 SWG) giving a final load of 3.2 lbs. An alternative spring of lower rating is shewn of 16 turns of .040 (19 SWG.) rising to 2.3 lbs. RETARD VIBRATIONS. X.9550 We note you have pointed out that the high centre of gravity of the EAC. engine may be one of the reasons for its retard vibrations being more noticeable. An experiment could be made to run a 40/50 with a heavy mass bolted on the top of the cylinders. The aluminium head and cyl. block which it is proposed to try at some time would have advantage in this respect. It should be pointed out that the only EAC. engine we have yet tried in a chassis is one that was designed to go in an underframe, and has not suitable arms for direct attachment to the main frame. The suspension of contd:- | ||