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 mounting modifications and their effect on chassis vibration ('jellying') on a 20 HP car.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan230 | |
| Date | 15th May 1929 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c.c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c.c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}2/LG15.5.29. 20 HP. 12-G4. Handwritten notes: X5770, X5807(crossed out), X5380 We have carried out the modification to the engine mounting, fixing the sandwich feet at the rear and the extra cross member in front, also the larger cross member in front of the radiator. Tests taken before and after the alteration shew that the jellying of the front of the car has been very considerably reduced, both comparisons being made with low tyre pressures. We consider that the engine vibration both forward and retard is now definitely worse than it was with the previous engine mounting. We have not yet a satisfactory explanation why 12-G4 car was so bad as regards jellying because we have another car 14-G4 which has the identical frame and engine mounting as we previously had on 12-G4 and this car is wonderfully good for absence of frame jellying. Further tests are being made in connection with this. Hs.{Lord Ernest Hives - Chair} | ||