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).
Issues found during the production testing of the Phantom III chassis and engine.
| Identifier | ExFiles\Box 91\1\ scan0273 | |
| Date | 19th May 1936 | |
| X300 Gry{Shadwell Grylls}- from Mr. Mx{John H Maddocks - Chief Proving Officer}10/T19.5.36 SBD PHANTOM III PRODUCTION TESTING. We now have a number of chassis on test, and have to-day put up to EF for acceptance the first of this type. We think it will be useful information to everyone to give our experience to date. Generally speaking the chassis have been very good but have not been free from troubles, which are briefly outlined below:- ENGINE. Valve Springs. We have broken a number of valve springs, both on the test bed and on the road. This trouble is a question of material and correct valve springs are still not available. Slipper drive. These have been found on examination to be much too high in loading, i.e. in the neighbourhood of 40 lbs. The recommended loading is 25 lbs. When the slipper drives were being produced in the Works, difficulty was experienced in obtaining the loading with the spring instructed E86968 and at the Works request the D/O issued E87759. We are now using XB1659 the Bentley slipper drive spring and this is giving us the correct poundage and we recommend it should be adopted for production. Water leak. We have had some trouble with water leaks from the cylinder head joint at high speeds on the test bed and we proved this to be a question of making a satisfactory seal between the flange joints of the cylinder liners and the crankcase. Water temperatures. On several chassis we have experienced high water temperatures. The instrument board thermometer showing 95°c. with the radiator shutters working correctly. This point is being investigated in conjunction with the Exp.Dept. and at the moment we are not able to say much about it. contd- | ||