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).
Push rod deflection, a new camshaft component, self-lubricating bearings, and future car frame design suggestions.
| Identifier | ExFiles\Box 173\4\ img163 | |
| Date | 16th December 1935 | |
| -6- Ha/Rm{William Robotham - Chief Engineer}/S/KR.16.12.35. Push rod deflection can cause noisy operation. With weak dural push rods they got valve closing curves thus:- and the tappet could not look after this. The new Wilcox Rich type that sits on the camshaft is far freer from trouble, provided it has air free oil. They found that on slowing the engine to idling after high speed running the oil pressure fell from 20 lbs. to 4 lbs. and the air in the oil immediately expanded and stopped the tappets working. They now have a valve so that the tappet oil cannot fall below 12 lbs. which shuts off oil from all the rest of the engine, the bearings sometimes having to go without any. Some very interesting work is being done on self lubricating bearings by the bearing Co. of America. The clutch thrust on the Packard 120 is one of these and we are bringing other samples. The balls run in Oilite rings separate by oil soaked felt. This is just what we want for the SpectreCodename for Phantom III clutch and wheel bearings. Park arrived yesterday and Cy. came to dinner. Cy. had two somewhat monumental suggestions - (1) For the Bentley an aeroplane fuselage construction in front to stiffen the frame. (2) All cars soon will have a 15° floor and 50" passenger room. There will not be room for our deep frame. A 4" frame and stiff body will be required. He thinks we ought only to accept bodies that pass the required torsional stiffness and start body builders thinking along those lines. Ha/Rm.{William Robotham - Chief Engineer} | ||