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).
Engine vibration differences between the 1300 and 1400 series due to cylinder capacity measurement errors.
| Identifier | ExFiles\Box 19\7\ Scan008 | |
| Date | 27th September 1910 | |
| C.J. X790 27th September 1910. R5/D27910 Re Engines. Absolutely the only difference in vibration at slow speed between the 1300 and the 1400 series is due to the error in the measurement of the capacity which has only lately been discovered. This is not due to design but in the actual cylinders, - they have been scraping them out so as to make the space which cannot be filled with oil from the top. None of us are favourable to any increase in the compress-ion for so many reasons as well as smooth running. When, however, the engines are running fast, the crank-shaft vibrations are due to the increase of compression and greater power at the higher speeds. This we intend, for the time being, to get rid of by still further increasing the combustion chamber until the compressions at high speeds are not greater than they were in the 1300 type. The last Works instructions were issued as 24.5 to 25 cubic inches, but this was due to the misunderstanding caused by the error due to measurement. This should have been issued as 26 ± ¼". Mr. Platford thinks that with 26 cubic inches there is little to choose between the 1400 and the 1300 engines at slow B'g'm 5M. 10/09 (E.R.) L. 1590 | ||