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).
The weakness and rattle in 20/25 HP engine gears and outlining potential solutions.
| Identifier | ExFiles\Box 30\2\ Scan315 | |
| Date | 19th September 1933 | |
| COPY. To Wcr. from Hs.{Lord Ernest Hives - Chair} c. to Hd.{Mr Hayward/Mr Huddy} Hs.{Lord Ernest Hives - Chair}10/MT.19.9.33. ENGINE GEARS 20/25 H.P. - Wor{Arthur Wormald - General Works Manager}2/R16.9.33. We know the weaknesses of the 20/25 HP. engine gears. We cannot dispute the rattle at low speeds and we see no alternative but to treat the complaints as they arise. The fact that there appears to be an epidemic of these troubles in Dundee it would appear that they may consider the rattle is cause for alarm. We think that if our man Reid was instructed that the rattle is entirely due to the reaction from the camshaft, and that there is not the slightest danger of them causing any harm we might be able to prevent some of these cars being returned to the works. The results on six Bentley engines which we know were infinitely worse for this trouble shows that the balancing cam on the camshaft drive eliminates this fault. The scheme as used on the Bentley cannot be applied to the 20/25 HP. cars on the road but we have arranged with the works that future 20/25 crankcases will be machined to take the balancing cam so that as soon as this has been standardised it will be fitted on to all 20/25 HP. cars as well as Bentley. For 20/25 HP. cars on the road E.{Mr Elliott - Chief Engineer} has designed a special scheme to suit these cars. It can be applied to existing crankcases without any machining but it will be necessary to modify the existing camshaft and to fit a new cam wheel with the balancing parts. We hope to have one of these made experimentally in ten to fourteen days and will push on with the tests so that it can be used to overcome customers' complaints. We can look forward in the future that this fault, which has worried us for years, can be eliminated. To correct existing cars will be a fairly expensive job and therefore we do not want to broadcast the news that this trouble can be easily overcome. Hs.{Lord Ernest Hives - Chair} | ||