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).
General remarks on the performance of the 10-EX car, detailing suspension, steering, and the Auto-Vac system.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 83 | |
| Date | 6th September 1927 guessed | |
| contd :- -3- GENERAL REMARKS 10-EX CAR. This car held the track remarkably well although it was necessary to have 70 lbs. friction damping in addition to the hydraulics to get the best results. The suspension appeared to be slightly over flexible for the high speeds attained as this shock damper loading gave uncomfortable low speed riding. We consider that Brooklands in its present condition is a very close approximation to a mediocre Continental road that can be taken at maximum speed. Steering. The .720 worm and nut on this car were lubricated with Iso-Vis oil. The steering began to get sticky after a few laps, and though it did not altogether tighten up, it became very unpleasantly heavy. This agrees somewhat with our previous experience that Iso-Vis is not an ideal lubricant. Since returning, we have lubricated this same steering with Castrol 'R' which has effected a very considerable improvement. On the track the steering was quite positive and owing to the tightening up, free from joggles. The axle was run with 4° backward pivot lean which gave a selective steering at all speeds with no signs of wobbles with high pressure or balloon tyres. On the whole the steering was rather more stable with balloon tyres. Auto-Vac. With a full tank, the autovac was just capable of supplying the requirements of the car at maximum speed. With an empty tank sustained full throttle work was not possible without occasional luffing up. contd :- | ||