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).
Alteration to the float chamber valve needle design and requesting a test of a new version.
| Identifier | ExFiles\Box 181\M11\ img081 | |
| Date | 23th November 1917 | |
| DY.{F R Danby} from E.{Mr Elliott - Chief Engineer} c. to CLK. ORIGINAL D/W24.11.17? 23 NOV 1917 RECEIVED X. 3225. Re - Float Chamber Valve. R.R. Chassis. Please find attached Drawing No. Le... showing an alteration to the design of the R.R. float chamber needle, in which the diameter has been reduced immediately behind the max. dia. taper, the XXXXXXXX of the taper has been reduced, and the guide has been fluted, all with the object of allowing free egress of the petrol. This drawing actually shows two designs, one of which viz., Fig. 1 and 2, was intended for future use. This is now cancelled and no notice should be taken of it. Would you therefore test Fig. 3. for future adoption on the chassis and send us at once for Chassis 7-CA, a needle made to drawing Fig. 3. This needle should be fitted with a collar as shown in Fig. 1, so that we can limit the stroke to .075. We want you to test this needle with such a stroke to ensure that the full power of the engine may be obtained with 1 lb. available pressure at the needle seat, which would be the case when the car is ascending a steep hill with 2 lbs. pressure in the petrol tank. You will understand that the limitation of the needle lift will in a way wire draw the petrol at the seat so that a reduced pressure will be obtained in the petrol chamber immediately above the needle seat which will have less power to hold up the needle against its desire to close. E.{Mr Elliott - Chief Engineer} | ||