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).
Technical analysis of the probable cause of shake, comparing torsional stiffness across various Bentley models and detailing attempts to stiffen the scuttle.
| Identifier | ExFiles\Box 117\2\ scan0054 | |
| Date | 21th July 1939 | |
| -2- Probable Cause of Shake - Cont'd.{John DeLooze - Company Secretary} The torsional stiffness of various cars is as follows:- lbs-ft.degree. Bentley II frame and dashboard } 365 " V frame } 1,400 " II Wooden saloon } 700-800 " II Steel saloon } 900 " V Steel saloon } 2,800 " V Coupé } 1,800 We have no figure for the old coupé, it is probably about 500-600 lbs.ft/degree. The resistance to roll on Bentley II's and V's is as follows:- Bentley II 150 lbs/degree. " V 336 " " Thus, although the disturbing forces in torsion on the frame have been doubled the rigidity of the car has also been greatly increased, even when comparing the new coupé with the old steel saloon there is no great discrepancy, and it must be remembered that the Bentley II's steel saloon did not shake like 10.B.V. A diagonal strut across the scuttle entirely stops shake without increasing torsional stiffness materially. It would seem that the cause of the shake lies entirely in scuttle weakness. Attempts to stiffen the scuttle. We have made certain measurements of scuttle deform-ation. The deflection was measured on the scuttle diagonal in the plane of the door pillars, the load of 100 lbs. applied at door catch level on the scuttle. The figures are as follows:- (1) Coupé as received, doors shut .005" (2) " " " open .008" (3) Saloon .000" | ||