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 graph of load, stress, and deflection for 25 HP chassis valve springs.
| Identifier | ExFiles\Box 106\5\ scan0057 | |
| Date | 28th November 1931 | |
| Deflection in inches Load in lbs. Stress in lbs/sq in Graph annotations: Stress at large end of spring increases to 102,000 lbs Spring H.451 Spring E56325 Choc. .8075 Initial deflection .330 lift .160 Coil Clearance .400 lift .090 do do. Std lift Higher lift .361 Initial deflection Bottom section: Comparison of 25 H.P. Chassis Valve Springs. Loads & Stresses are slide rule figures calculated on the mean coil dia. Stresses at large dia of spring should be increased 5% with a corresponding reduction for the smaller dia. end. Refer to T.C. 2610 for full characteristics of Spring E56325. Length per choc at EC 2610 = .864 Derby calculated choc = .950 Actual choc of enamelled spring = .985 Right side notes: .026 per coil } Unenamelled .015 per coil } Actual choc length of enamelled spring = .985 .011 clearance per coil Stamp: DERBY | ||