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).
Use of an American-made silent chain front end drive for the Wraith, with a comparison to a Cadillac's drive.
| Identifier | ExFiles\Box 128\3\ scan0139 | |
| Date | 26th November 1934 | |
| SECRET. To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}4/KW. 26.11.34. Chain Drive for the Wraith. We are trying to get some American made parts for the Wraith silent chain front end drive, so that we can do some endurance running on a rig. In the meantime we wrote and asked Hancock whether in his opinion the Cadillac front end was as quiet as that on 21-G-IV. We believe the Cadillac front end represents almost exactly what the Wraith is going to be. Hancock's reply was as follows :- "The chain drive on the Cadillac is definitely quieter than the 21-G-IV timing gears. Whether it will retain it or not is a matter of time, but considering the car had run 6,500 miles before we started our test, mileage now 12,750, we should say the result is promising. The engine in the Cadillac, before tappets became noisy and the water pump intermediate drive started to rattle, was dead quiet in listening in the driving seat. One did not know whether the engine was running or not. 21-G-IV. One can hear the dry metallic sound of the timing gears, one distinct tappet, but the worst feature is, one can feel the pulsations of the engine in both front seats. This is with the clutch out and taking no notice of the noisy petrol pump. With the clutch in, the side shaft gears are very distinctive and uneven." It would appear from this that so far we have no reason to reverse the decision to fit silent chain on the Wraith. Obviously, however, the life of the chain is of material interest to us, and therefore we want the car to run long enough in France to reassure us on this point. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||