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).
The adoption of the Autovac system, throttle casting heat treatment, magneto drive, and ignition switches.
| Identifier | ExFiles\Box 40\4\ Scan053 | |
| Date | 31th January 1923 guessed | |
| contd:- -2- in the early days we discouraged you from using the Autovac system. Since we have had it on the 20 HP. cars we have found it such a boon that we think every effort should be made to get it on the big cars. Also many of the European cars such as - Hispano, Delage and Fiat are using this system. What I should like to know is whether you have altered your views. When we use the Autovac we can then use a direct acting level indicator on the petrol tank instead of the magnetic type. Exhaust heated throttle. In connection with this we have found it necessary to heat treat the throttle castings before final grinding. We found that we had cases of distortion take place when the throttle was first heated up. We overcame this by having the castings heated up to 500°C and allowing them to cool off. Magneto Drive. We should anticipate, when you use the fabric magneto drive without the brakes that you will get slight rattle [handwritten] from [/handwritten] the slack in the magneto pinion and camshaft gear. In order to overcome this, we found it necessary to use [strikethrough] a [/strikethrough] plain thrust instead of the ball thrust and also light spring pressure. We should be interested to hear whether you have experienced any noise from the magneto pinion. Ignition switch. We have now two or three 40/50 cars running about where both ignitions are controlled by one switch. Although at first we considered we were quite open-minded about it, after having more experience, we considered that contd:- | ||