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).
Comparison of standard production (E.56325) and proposed production (Hs.451) valve springs.
| Identifier | ExFiles\Box 106\5\ scan0055 | |
| Date | 24th November 1931 | |
| -2- BY/SS{S. Smith}4/N.24.11.31 Cont'd.{John DeLooze - Company Secretary} This memo is issued in order for the Drawing Office to know clearly what they must instruct for production chassis. Comparison of Valve Springs. | | Std. Production E.56325 | Proposed Production Hs.{Lord Ernest Hives - Chair}451 | |---|---|---| | Valve Lift. | .330 | .400 | | Load. lbs. | | | | Valve Closed | 29 .1 | 65 | | Valve Open | 55 .75 | 97.6 | | Stress. lbs. per sq. inch. | | | | Valve Closed | 29 .000 | 65.000 | | Valve Open | 55 .700 | 97.000 | | Stress Range. lbs. per sq. inch. | 26 .700 | 32.000 | | Calculated Clearances (Per Coil) | .026 | .015 | BY/SS.{S. Smith} | ||