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).
Comparing the 12-cylinder Packard against the Spectre model, focusing on performance, weight, and power unit design.
| Identifier | ExFiles\Box 127\1\ scan0209 | |
| Date | 9th May 1935 | |
| Rm{William Robotham - Chief Engineer} x435 To Sg.{Arthur F. Sidgreaves - MD} and Wor.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} 12 Cylinder Packard. With reference to Sg.{Arthur F. Sidgreaves - MD}8/E.1.5.35 and Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/KW.8.5.35, we are in agreement with the latter report. We believe that the performance was definitely inferior to the SpectreCodename for Phantom III, and as regards the suspension this is, of course, conventional on the Packard and the back seat ride does not compare with that of SpectreCodename for Phantom III 1. To keep the front end of the frame quiet the bumper bar on the Packard is equipped with very heavy damping masses. Attention should be drawn to the weights of the larger American cars fitted with custom coachwork. Cadillac, for example, weighs 58 cwts and the Packard, so far as can be remembered, was given as 55 cwts. SpectreCodename for Phantom III 1 turned the scale at less than 48 cwts, and SpectreCodename for Phantom III 2, 49 cwts. It is true that we may have to accept more weight in the coachwork to obtain the degree of stiffness which we think will be necessary sooner or later, but we do not expect that this will amount to the difference in the above car weights over SpectreCodename for Phantom III, namely, 8 to 10 cwts. The power unit on the Packard appears to me to be quite a neat piece of design work, and most of the features excepting the valve gear are very accessible. The accessibility, however, of the dynamo and built-in water pump have only been obtained by using a belt drive and this is a feature that we do not think is justified on a high class car. It is true that double belts have been used but sooner or later these will give trouble unless replaced at regular intervals. In the case of the SpectreCodename for Phantom III engine, we have sacrificed a little accessibility to provide a gear drive for these units. The exhaust and inlet manifolding is an astonishing job on the Packard and it is evident that when using a down draught carburetter on this or any other type of engine a sump has to be arranged in the heated portion of the induction pipe with ball valve and drain tube to remove the heavy ends of the fuel and any flooding which accumulates therein. In the case of | ||