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).
List of modifications and drawing issue dates for the Spectre 12-Cylinder Engine.
| Identifier | ExFiles\Box 30\3\ Scan063 | |
| Date | 19th January 1935 | |
| - 12 - SPECTRECodename for Phantom III 12-CYL. ENGINE. BY.1/G.19.1.35. LeC. 4255 Modified Position of Horns ................. Recd. 14.12.34. Detail drawings completed and issued ...... 5.1.35. N.Sch. 4251 Modfn. to Speedometer Drive & Bolting ....... Recd. 1.11.34. Superseded by N.Sch. 4257. N.Sch. 4256 Modified Clutch Operating Lever ........... Recd. 8.11.34. Detail drawings completed and issued ...... 23.11.34. N.Sch. 4257 Servo Gears 2/21 Ratio and Speedometer Drive ... Recd. 9.11.34. Detail drawings completed and issued ...... 21.11.34. N.Sch. 4258 Stop to Limit Compression of Damper Bellows, Unit Con. Shock Damper. I.F.W.S. ............. Recd. 20.11.34. Detail drawings completed and issued ...... 19.11.34. N.Sch. 4260 Clutch Pedal Lever & Clutch Operating Lever .... Recd. 13.11.34. Detail drawings completed and issued ...... 22.12.34. N.Sch. 4261 Adjusting Washers. Upper & Lower Triangle Outer Brgs. & Pivot Lower Brg ................. Recd. 13.11.34. Detail drawings completed and issued ...... 13.12.34. N.Sch. 4263 Frame Modfns. to suit spherical Mounting for Marles Steering Box ..................... Recd. 16.11.34. Superseded by N.Sch. 4293. N.Sch. 4264 Modfns. to Gearbox Casing to accommodate a larger servo ............................... Recd. 14.11.34. Detail drawings completed and issued ...... 21.11.34. N.Sch. 4266 Pads on Yoke Piece for Measuring Pivot Lean .... Recd. 23.11.34. Detail drawings completed and issued ...... 13.12.34. N.Sch. 4267 Independent Front Wheel Suspension raised 0.500 Recd. 23.11.34. Detail drawings completed and issued ...... 13.12.34. N.Sch. 4270 Rear Axle Casing - Level Plug on L.H. Side ..... Recd. 22.11.34. Detail drawings completed and issued ...... 24.11.34. N.Sch. 4273 Rear Axle Centre Casing - Perfect Oil Seals on Rear Axle Shafts ....................... Recd. 23.11.34. Detail drawings completed and issued ...... 12.12.34. N.Sch. 4274 Brake Gear Damper & Front Brakes - Intermediate Lever. Recd. 4.12.34. Detail drawings completed and issued ...... 19.12.34. | ||