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 valve spring loads between a Chevrolet and a Wraith engine.
| Identifier | ExFiles\Box 10\3\ 03-page037 | |
| Date | 18th June 1937 | |
| 1 VALVE SPRING LOADS 18.6.37 CHEVROLET WRAITH Valve spring load } 41 1/2 lbs. .......................33 lbs. in closed position } in Open position 90 1/2 lbs. .......................94 lbs. Bottom tappet spring } load in closed } 5 1/2 lbs. No bottom tappet springs. position. } In open position 19 lbs. Total load closed.......47 lbs. ....................... 33 lbs. opened.......115 1/2 lbs. ....................... 94 lbs. ----- | ||