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).
Depot sheet memo regarding an investigation into engine pinking issues caused by a bent governor spindle.
| Identifier | ExFiles\Box 150\1\ scan0070 | |
| Date | 11th November 1935 | |
| To Hd.{Mr Hayward/Mr Huddy} (FOR DEPOT SHEET). HS{Lord Ernest Hives - Chair}/FD.{Frank Dodd - Bodies}7/KW.11.11.35. Engine Pinking. Apart from the governor characteristics which we are at the moment investigating, we have found that it is possible for the governor spindle to be bent out of truth, and so alter the timing between the cylinders. According to test, .005" difference in the contact gap alters the engine timing 4.5°. It is understood that should the spindle be out of truth the rotor blade spark tip will foul the H.T. points in the distributor, but there is one position where the rotor blade would clear, and that is if the shaft was bent facing the rotor blade sparking tip. We have had a case where the spindle was bent .017". This means that the cam tilts over .0085" and the contact gap closes .0145" making a variation of 13° early between Nos. 1 and 6 cylinders, with the other cylinders slightly less so according to the eccentricity of the spindle. Owing to the contact points being worn in service and so retarding the ignition slightly, we point out that although the variation is 13°, we did not get a maximum of 26° automatic advance. HS{Lord Ernest Hives - Chair}/F.Dodd. | ||