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 knocks and cylinder distortion issues found in the 20HP model.
| Identifier | ExFiles\Box 103\4\ scan0011 | |
| Date | 21th December 1927 | |
| X5050 By [REDACTED] c Hs.{Lord Ernest Hives - Chair} Mx{John H Maddocks - Chief Proving Officer}5/T21.12.27. re 20HP. Cylinders. We are at the present time having a certain amount of trouble with engine knocks on the 20HP. The trouble has not previously been much in evidence, but as pointed out in our report Mx{John H Maddocks - Chief Proving Officer}/McM6/T8.8.27, made at the time the 40/50 investigations were carried out, there is similar cylinder distortion occurring on the 20HP. In a recent particular case the distortion was as much as, on 2 and 5 cyls, .010 difference in diameter. This was successfully treated by strutting, as on the 40/50, in accordance with your instructions to try hand struts where necessary, in order to see if it had a beneficial effect on the 20HP as on the 40/50. [STAMP: RECEIVED] | ||