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).
Comparative analysis of a Lincoln 12-cylinder engine's features against other designs and an internal project named 'Spectre'.
| Identifier | ExFiles\Box 126\3\ scan0008 | |
| Date | 4th July 1933 | |
| - 2 - E.1/HP.4.7.33. used by Buick, but the angle of the spiral was considerably less, not more than 15º to the axis of the wheel. On returning to London I went out with Mr Macintosh on the Lincoln, and the impression gained is that they have achieved all that we expect from a 12 cylinder engine, with the exception that the engine appears to detonate when the throttle is opened at low speeds rather too readily. This may be accounted for in part by the use of "L" head cylinders, and we should expect a much better result from our own design of Rolls-Royce valves in the head engine. The Lincoln connecting rods are of the side by side type with a common floating bush, the bush not being restrained by the rods in any way but floating freely between the crankpin and the big ends. A similar scheme is used on the 8 cylinder Ford. The general layout of the engine is very neat but owing to the use of side by side rods the cylinder blocks are rather on the long side and have to be staggered, which adds to the length of the engine. The layout of the unit drives is very similar to what we are designing on the SpectreCodename for Phantom III and calls for the minimum number of timing gears, but in the case of the Lincoln the ignition tackle is at the dashboard end whereas we rather prefer it to be at the radiator end. The latter position, however, is denied to the Lincoln on account of the presence of the exhaust pipes within the Vee. It is remarkable that these exhaust pipes stand up as well as they appear to do, but being brought down at the front must be of considerable assistance in keeping them cool. The two manifolds are joined together into a single Vee pipe passing through the near side of the chassis. The combination of all the exhaust in one we think is good provided there is not too much back pressure in the system. In the case of the SpectreCodename for Phantom III the exhaust pipes are only on the outside of the Vee of the engine, and we shall probably bring them down the front and join them finally behind the flywheel, as it may not be possible to conveniently effect a junction at the front end. There are advantages to keeping the exhausts separate until a point behind the unit is reached. The steering box and steering column on the Lincoln | ||