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).
Customer complaints of a knocking sound in 20HP cars and a proposed solution involving a crankshaft changeover.
| Identifier | ExFiles\Box 6\1\ 01-page150 | |
| Date | 3rd October 1928 | |
| NOT. EF. HS.{Lord Ernest Hives - Chair} HY.{Tom Haldenby - Plant Engineer} MX.{John H Maddocks - Chief Proving Officer} Y/5010 228 Bm14/W3.10.28. OCT A few Owners of our 20HP. cars are complaining of a knock which can be heard at about 20 m.p.h. The degree of noise to be heard from this knock is to some extent controlled by the pressure on the Slipper Flywheel, but with the best setting we know, and the cotton duck fabric, this knock can still be heard. Our experiments led us to change the Crankshaft and replace it with one of the stiffer type: This has cured the knock with the pressure on the Slipper Flywheel set at 6 to 8 lbs. on a 17½" leverage. We have a few customers who are complaining very bitterly of this knock. Before we approach these customers, we should be glad to know whether it is agreed that we are doing the right thing. The cost of the changeover is £36.0.0d. Hm.{Capt. W. Hallam - Head Repairs} [Handwritten signature] | ||