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 to G.W. Hancock discussing issues with a clutch, timing gear rattles, experimental valve springs, and a noisy radiator fan.
| Identifier | ExFiles\Box 5a\4\ 04-page075 | |
| Date | 28th July 1934 | |
| x5840 To G.W.Hancock, Esq., Hotel de France, Chateauroux, Indre, France. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/S/KW. 28.7.34. Thank you for your report of the 26th, and daily reports. We are sending the spring loaded link out for the 25 HP. engine mounting almost immediately. The Repair Dept. have just made a very bad clutch into quite a good one by easing the splines, apparently if the pressure plate is a tight fit on the splines this trouble can occur. With regard to your timing gear rattles on the Bentley, we have been investigating our cars here when they have been fitted with silent tappets, and we have found that no oil at all goes to the timing gears in the ordinary way when the engine is hot and running below 500 r.p.m. Therefore to get silent tappets to work we have had to drill a hole in the relief valve as on the Phantom. It occurs to us that possibly the Bentley timing gears are rattling at low speeds due to these circumstances. We should like to know if this continues when they are being supplied with oil. We are sending you out a set of Bentley valve springs for the 20/25. Actually we do not want you to make too many comments about these tappets in the Daily reports because they are only experimental. We know that fitting the Bentley valve springs will make them more noisy for idling. What we are proposing to do is to drill the valves. With regard to radiators, the fan is very noisy on 21-G-IV. It is not so much the fan really as the alteration in radiator matrix. We want you to find out the minimum amount of fan to prevent the car boiling when idling, and also to give it a margin of safety when hill climbing. If this is still too noisy we may have to stick to the present type of radiator in spite of the large saving in weight of the Harrison. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||