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).
Brief outline of the specifications for the Phoenix Engine Unit.
| Identifier | ExFiles\Box 111\2\ scan0218 | |
| Date | 18th August 1937 | |
| SECRET 800. 1044 By.{R.W. Bailey - Chief Engineer} from Rm.{William Robotham - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Jnr.{Charles L. Jenner} c. Mostay. Rm.{William Robotham - Chief Engineer}1/AP.18.8.37 PHOENIX ENGINE UNIT The following is a brief outline of the specification of this engine as so far projected with some indication of the reason which lead to the recommendation in each case:- DISPLACEMENT (1) Bore and stroke 3¼ X 4½. (2) Provision for increasing the bore to 3½, and at the same time retaining water between all the bores, this being the extreme limiting size of the design. It was considered that 3½ litres was quite a big enough displacement for the market which it was hoped to get for this car. On the other hand, if the unit was a success, it would be desirable to be able to utilise it on the Bentley, as the existing Bentley unit is considered to be out-of-date in every way. There would be no objection to loose liners on the 3½ bore unit if this enabled length to be saved. CYLINDER CONSTRUCTION (3) Cast Iron Monobloc cylinder and crankcase with or without loose liners. From recent weight analyses we have been getting on American cars, it is apparent that it is possible to make a monobloc construction with a block length similar to the one we have at present on a Bentley for quite a reasonable percentage increase in weight. From experiments we have carried out, the monobloc construction gives a definitely smoother engine. It is, therefore, recommended that we closely follow American practice as exemplified by the Vauxhall, Chevrolet and Oldsmobile at present in the Experimental Dept. The present Bentley power unit complete with flywheel and clutch weighs 619 lbs and the Chevrolet 589 lbs. Water should be brought as far down the piston travel as possible. continued | ||