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).
The New Phantom exhaust cutout, detailing issues with a weak spring causing leaky valves.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan82 | |
| Date | 16th October 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF Hs{Lord Ernest Hives - Chair}/AJL1/1.G161025. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. BJ. c.c. to RQ. R.{Sir Henry Royce} c.c. to DA.{Bernard Day - Chassis Design} EY. c.i. to Wor.{Arthur Wormald - General Works Manager} ORIGINAL NEW PHANTOMCodename for PHANTOM I EXHAUST CUTOUT. YS490 We have received complaints from the Production Test Dept. concerning leaky cutout valves. We find the spring closing the valve is not sufficiently strong to definitely close the valve. Placed as it is in rather an exposed position it is necessary to close it very definitely in order to remove any dirt or soot that may have accumulated inside the nozzle. The load at present in the spring E.73301 when the valve is closed is only 3.7 lbs. In the fully open position this load is 8.5 lbs. We think the closed position load should be doubled to give a definitely closing valve. It is not however possible to increase this spring strength without increasing the strength of the toggling spring on the foot control in the same proportion, otherwise, in the open position, the valve spring will be stronger than the foot control spring and the valve will not remain open. This may produce a control which is difficult to work owing to the spring tension to be overcome. It might be possible to re-arrange the spring leverage and anchorage in such a manner that the spring tension is increased considerably in the closed position and remain approximately as it is now in the open position. Hs{Lord Ernest Hives - Chair}/AJL. | ||