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).
Comparing the smoothness and engine mounting of an Essex 6 Cylinder Terraplane to the 20/25 model.
| Identifier | ExFiles\Box 21\6\ Scan163 | |
| Date | 11th May 1934 | |
| x4217 To Hg. from E.{Mr Elliott - Chief Engineer} c. WOr.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} re Essex 6 Cylinder Terraplane. Replying to your memo Sg.{Arthur F. Sidgreaves - MD}2/E.9.5.34, I have now tried this car and am in agreement with what has been said with regard to its smoothness relative to the 20/25 RR. The flow of power and its quality of softness is most impressive, the only time when the engine becomes at all obtrusive is when it misses occasionally during idling. Under these conditions it appears to affect the car more than our own mounting. A small amount of solid friction might cure this fault. In applying the same type of mounting to the 20/25 unit, we have to deal with the reactions from the clutch operation, certain transmitted brake forces, and the pumping forces of the transmission. On the Terraplane the clutch operation is ingeniously carried out by the application of pure torsion no brake forces have to be handled, and the pumping of the transmission has to be carried by the elastic mounting alone. In the case of the 20/25 application we are compelled to provide definite end anchorage for the unit for the reasons already stated, and we have issued a scheme using links at the front end. We have arranged the pedal mounting to cantilever from the frame in a similar way to the present Phantom, and the linkage from the clutch pedal to the power unit is horizontal so as to allow the power unit to float without affecting the clutch operation. Weshould prefer to control the clutch by pure torsion but this cannot easily be applied in our case. With regard to the pumping forces of the transmission, we think it would be interesting to test the Terraplane on a suitable stretch of roadway to find what effect these have on the engine mounting. | ||