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).
Letter discussing a 10,000-mile report on Cadillac bearings, oil pressure, ignition timing, and engine mounting.
| Identifier | ExFiles\Box 125\2\ scan0187 | |
| Date | 15th December 1934 | |
| To G.W. Hancock Esq., Hotel de France, Chateauroux, Indre, Paris. X179a Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/KW.15.12.34. Thank you for the 10,000 miles report on the Cadillac and the observations on the lead bronze bearings. The one point we query in connection with the lead bronze bearings is the larger oil pump. With the existing system of relief valve we should expect to get pressures of 60 to 70 lbs. when the oil is cold. We should like to know whether this actually does happen. Are you completely satisfied that the whole system as fitted to 21-G-IV is ready for standardisation ? With regard to the pick-up on the 20/25. When going into the 20/25 high compression head we found that the governors they were making on production were very sluggish in their action at low speeds. This means that up to 25 m.p.h. a new car has considerably less ignition advance than one may expect from an old one where all the governor parts have got thoroughly free. In some cases of course the governor may never get free. We should like you to make a test definitely timing the ignition slightly too far advanced and then retarding on the hand control to get the standard setting. Then when you accelerate you can advance the ignition by means of the hand control and see what increase in performance is obtained. We are somewhat concerned about the drop in the engine mounting. We should like you to make recommendations as to what could be done to avoid this. We should also like you to get Leslie to have a look at it if you can conveniently get the car to Paris. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||