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 table of valve spring loads for a Chevrolet and a Wraith model.
| Identifier | ExFiles\Box 6\6\ 06-page226 | |
| Date | 18th June 1937 | |
| VALVE SPRING LOADS CHEVROLET WRAITH Valve spring load } in closed position 41 1/2 lbs. ..................33 lbs. in open position 96 1/2 lbs. ..................94 lbs. Bottom tappet spring } load in closed position. 5 1/2 lbs. No bottom tappet springs. In open position 19 lbs. Total load closed......47 lbs. .................. 33 lbs. opened......115 1/2 lbs. .................. 94 lbs. | ||