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).
Insufficient silencer clearance on the 40/50 chassis, recommending it be lowered by .500 inches to prevent vibration and drumming noise.
| Identifier | ExFiles\Box 171\3\ img069 | |
| Date | 1st October 1920 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Bn.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} c. to EB. [Handwritten: 647] [Handwritten: X.3438.] SILENCER ON 40/50 CHASSIS .5" LOWER. ------ There is a lot of difficulty on our present 40/50 chassis owing to the fact that there is insufficient clearance between the silencer andthe undershield, the silencer and front spring shackles, and the silencer and brake ropes. We have fitted up a car with a silencer front and rear .500" lower than standard. This is a very greathelp and makesa practicable job for production. Having the silencer .500" lower doesnot interfere with our ground clearance because there are other points on the chassis which are lower, and [handwritten insert: the larger wheels on standard, we can afford to drop the silencer] secondly, now that we are fitting this amount and it will still be relatively higher than the pre-war cars. If the [handwritten insert: exhaust pipe] silencer is touching the undershield it vibrates and causes a drumming noise at certain speeds. On 1.EX car we found this was happening. Mr. Royce will remember that 1.EX car appeared to have the 30 M.P.H. vibration very pronounced. We found the reason why it appeared so pronounced was because the Undershield was vibrating the exhaust pipe at that speed and caused a drumming noise. From all points of view we recommend that the Silencer should be dropped .500" lower. HS.{Lord Ernest Hives - Chair} | ||