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).
Test report on engine vibration in a 'Marmon' car under different mounting conditions.
| Identifier | ExFiles\Box 32\5\ Scan198 | |
| Date | 25th July 1922 | |
| Mr. Hives from GWH.{George W. Hancock - Head Chateauroux} X1692 25.7.22. "MARMON" CAR. Tests carried out with engine bolted down solid and released as Marmon standard. With the engine bolted down tight, a vibration period came on at 22 m.p.h. and finished at 24 m.p.h. Another period came on at approx. 43 m.p.h. and kept on right up. With the engine as Marmon standard the period vanished but a certain roughness came on at the same speed. The high speed vibration did not appear to be affected one or the other when engine was released or bolted down. The 22 m.p.h. period could not be detected easily if ignition was retarded. These tests were carried out with ignition fully advanced. GWH.{George W. Hancock - Head Chateauroux} | ||