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 required modifications for the Bensport model engine components.
| Identifier | ExFiles\Box 3\4\ 04-page200 | |
| Date | 15th February 1933 | |
| COPY. To WOR{Arthur Wormald - General Works Manager}, from E.{Mr Elliott - Chief Engineer} re Bensport. In response to your request, please note the following gives the list of modifications required on Bensport:- (1) Cylinder Block. A new cylinder block is required with the transverse induction passage that we have on the present 20/25 cut out. This cylinder block also has circular covers on like Phantom II and the old J.I. engine, and Mr. Walker is using some of the metal pieces from the old J.I. pattern on this new Bensport pattern. This cylinder block was instructed originally for the final Bensport before the decision to make 200 off the first model was taken, and will therefore come in for series 2 Bensports also. (2) Crankcase. The new upper half crankcase is required as you are aware because of the modification to the dynamo and drive. Incidentally it introduces the larger crankshaft with studded main bearings which is standard on 20/25 production after Z. series and permits the fitting of a mechanically driven petrol pump. We are hoping that the same casting can be used on 20/25 after Z. series but with the standard 20/25 dynamo fitted and standard manifolds. The present 20/25 lower half crankcase will be used on series 1 Bensport in conjunction with this new top half, assuming that as a result of the testing in France we do not run into excessive oil temperatures. (3) Wheelcase. A new wheelcase pattern is required to match the alteration to the crankcase for one to one dynamo drive. We hope that this new casting will also be useful on 20/25 production after Z. series. (4) Exhaust Manifold. A new pattern for the existing manifold is necessitated by the introduction of the larger dynamo. (5) Oil Filler. This is only a small item, but a modification to the casting will be required on account of the modified dynamo. | ||