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).
Valve spring rating chart for a Lorraine-Dietrich engine.
| Identifier | ExFiles\Box 22\4\ Scan110 | |
| Date | 29th March 1927 | |
| (13) LORRAINE-DIETRICH ENGINE. Valve Spring Rating Chart. LOAD (LBS) 50 40 30 20 10 0 RESULTANT. OUTER SPRING. INTERMEDIATE SPRING. INNER SPRING. VALVE LIFT (INCHES) .1 .2 .3 .4 VALVE CLOSED. VALVE OPEN. | ||