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).
The condition of cast iron tappet blocks after endurance testing at various RPMs.
| Identifier | ExFiles\Box 96\2\ scan0263 | |
| Date | 2nd November 1937 guessed | |
| -2- UNIT. NO. 1. (4) Cast Iron Tappet blocks. Standard SZN bottom tappets, with exception of A.1 in Ubas. Tappets set at .006" and .008" 1 hours endurance at 2000 R.P.M. | Tappet No. | Condition of Tappets. | | :--- | :--- | | A.1 and B.10 | Good surface, groove hardly perceptible. | | A.9 and B.8 | Lightly scratched " " " | | A.4 and 12. B.1,4,6,9,12. } | Scratched " " " | | A.8 and B.2 | Good surface, groove approx. .025" wide. | | A.2,5,6,7,11. } B.5, 10. | Lightly scratched " " " | | A.3. B.3,7,11. | Scratched surface " " " " | 1 hours endurance at 2500 R.P.M. | Tappet No. | Condition of Tappets. | | :--- | :--- | | A.1. - UBAS | Good surface, groove hardly perceptible. | | A.2,9,11, B.5,8,10 } | Lightly scratched " " " | | A.12. B.1,6,9,12. } | Scratched surface " " " | | A.5,7,8. A.6,10. B.2,7. } | Good surface, groove approx. .025" wide. Lightly scratched " " " Scratched surface " " " | | B.11. | Scratched surface " " " | 1 hours endurance at 3000 R.P.M. | Tappet No. | Condition of Tappets. | | :--- | :--- | | A.9,12. | Good surface, groove hardly perceptible. | | B.1, 8. | Lightly scratched " " " | | B.12. | Scratched surface " " " | | A.5,7,8. B.10. | Good surface Groove .025" wide. | | A.1,2. B.5,9. | Lightly scratched, " " " | | A.11. B.2,6,7,11. | Scratched surface " " " | | A.6,10. | Deeply grooved .100 wide. | | ||