Letter to Leyland Motors regarding hydraulic tappets and a 12-cylinder crankshaft.
| Identifier | ExFiles\Box 158\5\ scan0079 | |
| Date | 4th November 1940 | |
| 13/60 Valves gen: put Inderliste in Leyland file Rm. {William Robotham - Chief Engineer} 3/ML. 4.11.40. C.V.Pilkington,Esq., Leyland Motors Ltd., LEYLAND. Lancashire. Dear Pilkington, Herewith the information on hydraulic tappets which I promised you. I am sending you Hs. {Lord Ernest Hives - Chair} 1210, which shows the general arrangement of the hydraulic lash adjuster on the valve end of the rocker, and Hs. {Lord Ernest Hives - Chair} 1206, which shows details of the actual tappet; also Hs. {Lord Ernest Hives - Chair} 1209. E.83438 shows the general arrangement of the valve gear to which the tappet was fitted. We actually abandoned this valve gear in favour of General Motors eccentric type, and I am very sorry we did so. We actually ran these tappets for about 4 years on an engine and never had the slightest trouble with them. As we had nothing but a very coarse gauze strainer as an engine filter, we had to put a special filter in the valve gear. In your case, with by-pass filters, this should not be necessary. You will note that the reports says that the tappet was overloaded for the size of the valve gear, but this is only because we demand a very high degree of silence, and the effect of .003 thou: tappet clearance produces rather more noise than we like. Again, in your case, the ratio of tappet size/valve gear, based on the drawings we have sent you, should be perfectly satisfactory. With regard to your 12-cylinder crankshaft. It is almost impossible to predict accurately the frequency of amplitude of the vibration without particulars of the crankshaft, big ends, pistons and also an indicator diagram. - Continued - | ||
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).