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).
Failures and recommendations from a 50-hour front-end bumper test on a Bentley III.
| Identifier | ExFiles\Box 119\1\ scan0129 | |
| Date | 23th August 1938 | |
| Bentley III Bumper Test. Front End. 50 Hours run on 3" Cams. Failures. | Recommendations or remarks. N.S. rebound buffer after 6½ hours. | This was a 55 durometer hardness buffer and was replaced by a 45 which finished the run in good condition. O.S. Top torque arm stud sheared, after 10 hours. | O.S. Damper lost load due to valve seizure after 10 hours. | Seizures due to rubber from glands getting into damper. O.S. damper lost load after a further 8 hours. One broken piston, one broken link, and valve seized. N.S. rebound buffer also failed. | Failure of buffer due to valve seizures. Breakages due to failure of buffer. Rebound stops were then fitted and prevented further breakages or buffer failures. Rebound stops are to be fitted on G.B.V. O.S. Damper. No load on rebound after 5½ hours running due to breakage of replenishing valve spring. | Inferior springs at present in use. Correct ones expected in a day or two. O.S. Damper lost load on rebound. stroke after a further 7½ hours. Broken replenishing valve spring. | O.S. damper lost load again after a further 2½ hours. Valve seized again. N.S. Damper valve also seized. | The glands were wearing so badly, and doing so much damage to the valve that it was decided to complete the run without them. | ||