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).
Investigations into shock damper rattles, valve gear clatter, bearing failures, and engine/gearbox alignment.
| Identifier | ExFiles\Box 91\1\ scan0168 | |
| Date | 30th November 1935 | |
| -4- (16) Shock Damper Rattles. Being investigated, but we have proved that if a shock damper is 100% it is quiet on the car. (17) Valve Gear Clatter at High Speeds. Parts were sent out to Hancock to try and overcome this trouble, but up to the time of the car being written off we had not had a report. The 10,000 miles report shows that considerable trouble has been experienced with the hydraulic valve gear and it will be necessary to alter the filter on the next test. Various modifications in design are also being manufactured. Points which have arisen since the last memo. was circulated are as follows :- (1) Connecting Rod Bearings. The position of these is not satisfactory. Hancock's bearings failed in France. We have carried out endurance running on two different types of white metal bearings on the test bed and the results have more or less reproduced Hancock's failure. The original test was run in France on lead bronze and these also failed. Hall's bearing metal is being tried on the Bentley, but it has not reached a stage of development where it is worth carrying out tests in parallel on the SpectreCodename for Phantom III. We think we can undoubtedly make the SpectreCodename for Phantom III bearings work in lead bronze if we can get the right lubrication. Tests are proceeding. (2) Alignment of Engine & Gearbox. Now that we have handled two or three cars we find that the chassis is definitely susceptible to the alignment of the engine and gearbox. Previously we thought that there was considerable latitude in this respect. Since, however, for engine smoothness we are forced to use flexible rubber engine mountings and for gearbox silence we are forced to use flexible gearbox mountings, it is rather difficult to ensure that these two units shall remain perfectly in line. However, since Hancock has not reported trouble on his 15,000 miles test, we are not unduly concerned. It does, however, seem to be a reason against separating the engine and gearbox on the new 20/25. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||