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).
Technical memo discussing engine damper settings to reduce frame jellying on various car models.
| Identifier | ExFiles\Box 104\3\ scan0161 | |
| Date | 8th March 1932 | |
| -2- HS{Lord Ernest Hives - Chair}/Les.7/KT.8.3.32.cont'd.{John DeLooze - Company Secretary} takes place when the dampers are made solid. When the engine has been rigidly attached to the dampers, we hope to be able to considerably reduce frame jellying. The easiest way to make the dampers solid to the engine is to connect them from the front of the engine to the side of the frame, as on our present 25 HP. We should, however, like to avoid this if it is possible to make the present dampers on J.III sufficiently rigid to the engines. We consider it an advantage to have the dampers as far forward as possible in order (a) to have the maximum control over the front of the frame to reduce jellying. (b) that the engine vibrations both on the forward drive and retard, may diminish as far as possible before they reach the body of the car, (c) to keep the torque reaction period below the driving range by having sufficient flexibility between dampers taking the engine torque and the body of the car. We think that P.2. has a practically ideal engine mounting except that the engine alone has not sufficient inertia in order to damp the frame in some cases. There is a curious difference between the possible damper settings of 25 HP. and P.2. cars. We are restricted from using any sensible degree of damping on 25 HP. cars because of body booms although on P.2. cars the dampers can be solid with practically no signs of booms. The standardised setting of P.2. engine dampers is 7 times that of 25 HP. We should have no fear in raising the setting of the dampers of P.2. still higher, where as the 25 HP. is already at the top limit. We do not know whether this is caused from the fact that the dampers are further from the body, or that the dampers are connected to a crossmember on P.2. We hope that the dampers on J.III, Peregrine and Bentsport will be similar to P.2. that is not sensitive to body booms. Hs{Lord Ernest Hives - Chair}/I. A.{Mr Adams} Leslie. | ||