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).
The feasibility and benefits of a Vee eight engine, comparing chassis layout, suspension, and production costs against straight-eight models.
| Identifier | ExFiles\Box 6\6\ 06-page035 | |
| Date | 14th October 1935 | |
| (2) The steering however can be accommodated by leaving more room than usual between the rear end of the engine and dash. We went over this matter very carefully in 1931 and made a chassis layout which showed an overhead valve Vee eight engine 3" bore x 4 1/8" stroke arranged in the present dimensions of the 20/25 bonnet. Actually the front axle could be moved nearer to the dash in this scheme by 2.5 inches, and with independent front suspension there could be a total saving of 6" from front wheels to dash compared with using a straight eight engine, and compared with present 20/25. In the case of the SpectreCodename for Phantom III chassis we saved 8" on this dimension compared with the Phantom II. The 8 cylinder Vee engine with an independent front wheel suspension would, therefore, provide a proportionate saving on length and chassis weight etc. compared with a straight '8', and would be a logical development of the SpectreCodename for Phantom III policy. As previously indicated the difficulties which once ruled this engine out have largely disappeared, and there is today a tendency for this type to develop. No one can fail to be struck with the compactness of this form of power unit in its side valve form, and there is little reason why the overhead valve type which we should favour should not be nearly as compact. The work that has been done in improving the induction system was developed by Ford's on their Vee '8', and I was able to see at the Paris Show on the exploded and sectioned model of the twin 10 how the opposite ports of the induction system have been married up to improve the induction pipe characteristics. With regard to cost of production, this has to be most carefully considered in relation to the Wraith chassis, and in this respect the Vee engine should be compared with the straight '8'. To offset certain obvious increases of expenditure on the former there are economies rendered possible by | ||