Close-up photograph of an engine cylinder head, showing the combustion chambers and valve guides.
| Identifier | ExFiles\Box 179\2\ img101 | |
| Date | 31th December 1931 guessed | |
| ", | ||
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).