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).
Trouble with and revised designs for the mixture adjustment on the 20HP and Phantom models.
| Identifier | WestWitteringFiles\T\2July1928-December1928\ Scan075 | |
| Date | 24th August 1928 | |
| FROM E.{Mr Elliott - Chief Engineer} C. to HS.{Lord Ernest Hives - Chair} 20HP. MIXTURE ADJUSTMENT. X5080 ? X5080 Owing to the recent trouble with the mixture adjustment on the 20HP. Fabric Coupe used by R.{Sir Henry Royce} during the holidays, we have somewhat revised the design of this part, and send herewith LeC. 2585., shewing the modifications. The faulty lever failed to grip even although the screw was screwed up tightly, and the result was that the engine would not run slowly due to the low speed jet screwing itself down. We carried out a temporary cure by slotting the hole in the lever to reduce its resistance to tightening, and putting a spring washer under the head of the screw to increase the elasticity, so that when the screw driver torque was released there would be a tendency to grip. It appears to us that the act of tightening with a screw driver tends to cross wind the lever on the needle bush and resist the closing of the split boss of the lever. This however cannot be helped, and we can only reduce the resistance offered by the lever, and increase the efficiency of the tightening medium. The former has been done by a modification to the shape of the metal surrounding the slot hole, and the latter has been done by substituting the conical bolt and nut in place of the present screw. These modifications also apply to the Phantom, and we shall be glad if you would prepare a drawing for the Phantom on these lines. E.{Mr Elliott - Chief Engineer} | ||