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 vibrations felt at various points on a rigid test bed.
| Identifier | ExFiles\Box 43\1\ Scan073 | |
| Date | 25th September 1924 | |
| R.R. 493a (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -4- Expl. No. REF.HS{Lord Ernest Hives - Chair}/TAG/LG2.2.25. VIBRATIONS. When the engine was on the rigid test bed, there were two distanct vibrations at 1800 r.p.m. felt at three points, namely :- Lower half crankcase (L.H.C.C.) Carburetter stays (C.S.) Carburetter body (C.B.) At two of the points the L.H.C.C. and the C.B., the vibration appeared to be synchronised with each other, and were very much slower than the vibration of the carburetter stay which had a very sharp or quick period, graphically it would appear to be viz :- L.H. CC. C.S. C.B. When the bolts at the crankcase end of the stay are loosened, the rate of the vibrations alters. The L.H.C.C. slow as above and the C.S. and C.B. much quicker :- L.H.CC. C.S. C.B. and when the stays are slacked at the carburetter body, and tight at the L.H.C.C., the period in the stay is like that of the crankcase, and the C.B. is still very quick :- L.H.C.C. C.S. C.B. When the engine is mounted on the hanger, the vibration on the carburetters is very much lighter and is still more synchronised with the general vibration of the engine, and there is no distinctive vibration on the contd :- | ||