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).
Proposal to modify Wraith III valve guides by removing gland packings and experimenting with a new type on inlet valves only.
| Identifier | ExFiles\Box 10\3\ 03-page071 | |
| Date | 7th September 1937 | |
| Ex. Dept. c. to Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/Smdl. 654 DA.{Bernard Day - Chassis Design}9/G.7.9.37. WRAITH 111 - VALVE GUIDES WITHOUT GLAND PACKINGS. Please receive herewith E.CD.56 Valve Guide without Gland Packing. It has been found that the existing gland packings become very hard after a while in the engine, and so do not follow up and maintain the initial close fit with the valve stem. In view of this, it is suggested that the packings are therefore of little value and could be deleted. An efficient packing can be of great value on the inlet valve by preventing air and oil from being sucked into the cylinder, it would therefore be worth while to try a scheme with the packing deleted from the exhaust valves only and to retain the packing on the inlet valves, made from asbestos and high melting point grease, which would keep the packing pliable for a longer period than the present asbestos and tallow packings. Will you please detail and instruct experimentally. This scheme is also applicable to 25/30 HP. and Bentley 11, but not for Phantom 111, as the guide in an aluminium cylinder head would tend to come loose when hot and would require a retaining load, and the valve spring would require a base washer. DA.{Bernard Day - Chassis Design} | ||