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).
Progress report on the development and testing of the Wraith model, detailing ongoing technical issues and future plans.
| Identifier | ExFiles\Box 142\2\ scan0407 | |
| Date | 9th August 1937 | |
| SECRET. Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Hs.{Lord Ernest Hives - Chair} c. By.{R.W. Bailey - Chief Engineer} c. RHC.{R. H. Coverley - Production Engineer} WRAITH MATERIAL. In about three weeks' time we hope to be able to release the majority of the Wraith chassis to the Works. This does not mean that no further alterations will be necessary, but that we shall have covered 5,000 miles in France with the pieces released on the suspension, brakes, steering, rear axle and frame. With regard to the engine unit, the parts we released have an "odd on" chance of success. The general Wraith position is, that the only part which has failed in France is the front engine mounting. It is not difficult to improve this. The engine unit running in France is, of course, now out of date, but will give useful endurance results for the durability of the crankshaft main bearings and the tappets. In the last month we have overcome the major troubles reported in the way of engine vibration and valve gear noise. We now have an engine unit which is quiet, is smoother than the present 25/30, and, at the same time, gives an appreciably better performance. The problems which remain to be solved are, the oil leak from the rear main bearing with which we think we can deal in the next three or four weeks, and the fuel system. The car running in France during the hot weather has demonstrated the fact that the fuel system as originally designed is not free from vapour lock, but we are certain that before the end of the present hot weather we shall have found a solution to this trouble, even though it may mean abandoning the mechanically-operated pump. Tests on the Oldsmobile which is being taken across to France this week will demonstrate whether a mechanically-operated pump, as used by the Americans, is inferior to our electrically-operated pump, or whether it is the way in which it is arranged on the Wraith that is causing trouble. At the present moment, the proposed programme is to continue running the Wraith car in France until we have completed an engine unit to the final specification which we can now lay down, and which will include the latest American type mechanically-operated pump. We should then like to bring the car back | ||