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).
Summarizing experimental findings on rear axle dither, hydraulic tappets, engine durability, and frame stiffness.
Identifier | ExFiles\Box 4\1\ 01-page319 | |
Date | 11th April 1938 | |
-4- Rear Axle Dither. We have demonstrated experimentally that we can get rid of this by giving the rear spring shackles a certain amount of sideways and rotational freedom. Unfortunately this appears to spoil the directional stability of the steering above 70 m.p.h. We are investigating a scheme with reduced freedom of movement. Hydraulic Tappets. Phantom II experience shows that the plungers must be run with .0015 to .002 clearance if the valves are never to be held open when starting up. Power Unit Durability. The trouble with the big end bearings when running at 4,500 r.p.m. has been eliminated by increasing the side clearance on the blade rod. We have had several short runs at maximum revs. which indicate that there is no obvious weakness present in the engine. Duration running will be undertaken as replacement parts become available. Frame Stiffness. We are comparing the stiffness of the Cadillac and SpectreCodename for Phantom III frames and shall shortly issue a report. Dashboard. Experiments have been carried out which demonstrate that the dashboard can be fixed solidly to the body without bringing up booms. The double dashboard does not facilitate noise insulation. SpectreCodename for Phantom III 3 chassis is completed and waiting for the body, which should arrive before Easter. Briefly, it appears to us that it will be worth sending SpectreCodename for Phantom III 3 to France soon after it is completed. Ha/Mc. | ||