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).
Performance of the clutch, engine unit, and suspension.
| Identifier | ExFiles\Box 6\6\ 06-page311 | |
| Date | 20th September 1937 | |
| -2- CLUTCH. The clutch was exceedingly smooth and progressive under 99% of the running conditions. However, on one or two occasions after the car had been driven fast for a number of miles, it jaggered. When the clutch did jagger the impression given was that the geometry of the pedal movement relative to the engine movement was not 100%. There were no signs of rattles in the transmission at any time. Whether due to the increased moment of inertia of the flywheel or not we are unable to say, but there did not appear to be any tendency for the engine to stall when starting from rest. ENGINE UNIT. The valve gear on this unit is not, of course, passable. The idling is not passable. The petrol consumption is not passable being somewhere about 13 m.p.g. at an average speed of 40 to 45 m.p.h. The freedom from detonation is exceedingly good. The oil consumption seems to be about 1500 m.p.g. If oil was leaking out of the rear main bearing on this car, it must have been doing so in very small quantities. The relief valve is noisy when starting up with the oil cold. There was no popping back in the silencer. If no Wraith cars were to be worse than this, we consider the engine mounting to be passable. There are, of course, thuds when picking up below 15 m.p.h. and engine booms occurred about 45 m.p.h on 3rd speed. We think this engine mounting represents a good point to start from with the raised engine mounting. SUSPENSION. In the soft position we consider the suspension is ideal both at low speed and at high speed on good main roads. On a certain type of undulating road, however, there is too much front end movement even with the dampers in the fully hard position at high speeds; in other words, more damping is required in the fully hard position. We should arrange to get this damping, but in so doing it is imperative that at no speed should the damping be altered in the fully soft position. There are some very bad rattles in the front suspension when running over pot holes; these should be investigated. | ||