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).
Specifications and corrections for engine timing, contact breakers, and rotor positioning.
| Identifier | ExFiles\Box 4\1\ 01-page208 | |
| Date | 7th January 1935 | |
| -2- The timing of each cylinder should not vary more than 2º crank angle, which means that the breaker cams must be absolutely concentric with the governor shaft and the governor shaft itself run perfectly true. The maximum gap on one contact breaker should not vary more than .001 on each cam peak, and the timing of one contact breaker must be followed at 60º crank angle by the other contact breaker with a limit of 2º crank angle, throughout the timing of the 12 cylinders. It is essential that these points be checked over and set before the governor is fitted to the engine, as with the employment of two contact breakers any eccentricity is doubled in the relative timing error. On both No. 1 & No. 2 SpectreCodename for Phantom III units it has been necessary to crank the rotor blades in order that when firing takes place the rotor blade be in line with the distributor contact pins. This is due to incorrect positioning of the rotor keyway and should be corrected. These figures may require slight modification when the short duration camshaft is fitted. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||