Modifications to the torque arm, lower triangle lever, and thrust stay for the front suspension.
| Identifier | ExFiles\Box 100\1\ scan0221 | |
| Date | 9th December 1938 | |
| BY {R.W. Bailey - Chief Engineer} /NS {Norman Scott} c. Rm. {William Robotham - Chief Engineer} 446 DA. {Bernard Day - Chassis Design} 16/G.9.12.38. MODIFIED TORQUE ARM, LOWER TRIANGLE LEVER AND THRUST STAY, FRONT SUSPENSION, B.V, and E.50. FD. {Frank Dodd - Bodies} 325. To overcome the foul between the cross steering tube and the torque arm, the hole in the torque arm for the cross steering tube has been enlarged to the shape shown on sheet 2 of FD. {Frank Dodd - Bodies} 325. This has necessitated dropping the lower part of the torque arm by 0.4", thus reducing the ground clearance under it by that amount, but it is still higher than the thrust stay on full bump. To arrive at the shape of the hole in the torque arm, the steering geometry has been laid out, in plan view on sheet 1, and along the triangle axes on sheet 2. In this for the first time account has been taken of the lowering of the sphere at the back of the torque arm, an average amount of 0.375" being assumed for this lowering. This figure of 0.375" was arrived at after examination of all experimental chassis so far built. At the same time as this alteration was carried out, the thrust stay was altered at Ey's suggestion from a round section with offset ends to a neater looking and lighter channel section. This increased the worst ground clearance by approximately 0.150", under the nut at the end of the thrust stay, and the ground clearance under the general length of the thrust stay is increased by approximately 0.125". In order to use this type of thrust stay without having a long boss hanging down from the lower triangle lever, subjecting the lever section to torsion, the part of the lower triangle lever between the spring seat and the inner end is curved down. This is shown on sheet 1 of the scheme. A lever embodying this alteration will be required for Wraith 80 also. The details required have already been made in BY {R.W. Bailey - Chief Engineer} /HEB {H. Biraben} 's Section. DA. {Bernard Day - Chassis Design} | ||
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).