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).
Engine testing issues including excessive vibration, starting difficulties, and a fractured crankshaft.
| Identifier | ExFiles\Box 133\2\ scan0152 | |
| Date | 14th June 1935 | |
| - 5 - Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead}1/GB.14.6.35. EXCESSIVE VIBRATION. During the earlier tests it was found that the unit vibrated excessively at the higher engine speeds, due to the slight flexibility of the test bed. This vibration caused flooding of the carburetter and on one or two occasions caused the cylinder retaining nuts to become loose. The first trouble was temporarily overcome by mounting the carburetter independently and connecting the induction pipe to the engine by means of rubber section. It was eventually found necessary to grout the underside of the test bed with liquid cement and to stiffen up the engine mounting before these troubles were finally overcome. STARTING. Difficulty in starting this engine was experienced at the commencement of the tests; this being due to the speed of the starting gear (360 R.P.M.) being too low. The speed was increased to 720 R.P.M. when starting presented no difficulty. FRACTURED CRANKSHAFT. The importance of not allowing the engine to run at very low speeds is illustrated by the fact that half-a-dozen attempts to start this unit at 360 R.P.M. (when keyed to the starting gear) were sufficient to fracture the crankshaft. This was due to the inertia of the starting gear. ------------------- The tests on this engine are in abeyance, the bed being required for the 'Exe' Single Cylinder Unit. When opportunity permits, further running will be carried out with alternative valve timings and pistons. ------------------- Hs{Lord Ernest Hives - Chair}/Wd{Mr Wood/Mr Whitehead}/C.H.Parkingon. Attach prints (sheet 1 and 2) | ||