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).
Service troubles report on worn camshafts and tappets for the PH.III engine, detailing alternative solutions.
| Identifier | ExFiles\Box 131\3\ scan0105 | |
| Date | 18th July 1939 | |
| 11/S. Polee SWDL{Len H. Swindell} Sg{Arthur F. Sidgreaves - MD} from Mr. Hs{Lord Ernest Hives - Chair}- -C -Py -Rm{William Robotham - Chief Engineer} -De SERVICE TROUBLES Further to Mx.{John H Maddocks - Chief Proving Officer}1/MG.22.6.39, the following progress has been made. WORN CAMSHAFTS & TAPPETS. PH.III Running of the engine on the bed continues. We have several schemes in hand, but a good deal more running will be necessary to arrive at any conclusion. The alternatives we have in hand are:- 1. Stellite faced tappets in conjunction with standard camshaft. This gives promise of being more reliable than the Chromium plated tappet, the Chromium of which tends to flake or chip off. We do not yet know its effect on the camshaft as regards scoring, but there are indications that it is little or no worse than Chromium. 2. Fescolised camshaft. This process consists of applying a hard deposit on the cams of any desired thickness. It has been used by the L.G.O.C for some time to get them out of somewhat similar trouble. The process is of considerable promise, in that worn or scored camshafts can be ground down and then deposited up to size again, the finished camshaft then being probably better than new at a cost of under £3. A shaft which had to be re-ground .018" undersize owing to scoring has been reclaimed in this manner and is being fitted into an engine for running on the bed. 3. Cloudburst Hardened tappets. In view of the evils associated with Chromium plated tappets, leading ultimately to self-destruction, we have now decided to delete the Chromium plating on all replacement tappets, since we are quite sure we can run unplated tappets without running into any other troubles. (continued) | ||