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).
Investigation into complaints of valve bounce on a Phantom III large valve cylinder head.
Identifier | ExFiles\Box 133\1\ scan0101 | |
Date | 3rd September 1936 | |
To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Copy RHC.{R. H. Coverley - Production Engineer} Do. Hs{Lord Ernest Hives - Chair}/Edwards. X1129 E/PSN.1/MN.3.9.36. Car Universal Single Cylinder Unit. Phantom III Large Valve Cyl. Head. We have investigated complaints of valve bounce at 4300 R.P.M. on the above cylinder head and find that the length of the spring in the closed position is 1.700" instead of 1.600" as called for on LeC.4338, thus reducing the load from 67.5 to 51.5 lbs. Will you please check that the valve spring length is correct in the closed position on the rebuild of the above head, and use packing washers under the bottom spring washer if necessary. With the valve spring length correct in the closed position the valve gear should operate satisfactorily up to 4500 R.P.M. E/PSN. | ||