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).
Design considerations for the Wraith II and the testing schedule for the Big Bore 20/25 engine.
| Identifier | ExFiles\Box 30\1\ Scan265 | |
| Date | 1st December 1935 | |
| - 5 - 20/25 h.p.ROLLS-ROYCE Wraith II (contd) type fixings rather than bolted on hubs. Drawings were produced by E.{Mr Elliott - Chief Engineer} showing the chassis lay-out, and the advantages to be gained in body space, which total 8" by reason of 2" longer wheelbase plus the dashboard being moved 6" forward. E.{Mr Elliott - Chief Engineer} pointed out that as we require extra room inside the body it would be inadvisable to move the back seats forward by the full amount, but it would be preferable to give at least 2" to the back portion of the body and another inch in the front. E.{Mr Elliott - Chief Engineer} stated that in regard to this model - Wraith II - even with the 12-cylinder engine the bonnet would be no longer than it would be for the big bore engine or the V8 engine. Eg pointed out that it was to be regretted, by reason of the fact that this model cannot be introduced until about the Show of 1937, we should have to carry on even then with a gearbox without second speed s/m.{Mr Moon / Mr Moore} Nevertheless, it seemed inevitable as the amount of work involved in introducing second speed s/m between now and then would not really be justified. It is hoped that the big bore engine will somewhat make up for that omission. Big Bore 20/25 In view of the above re Wraith II, it is clear that we will have to carry on with the present chassis and big bore 20/25. Tests in France have not yet been made. 21-G-IV is due for test almost immediately, but has not the engine with the final head. This latter will be ready very soon, and will be fitted for test into a new car supplied by E.{Mr Elliott - Chief Engineer} As, however, so much of the testing work done on the big bore Bentley is applicable to the big bore 20/25 on it was considered that the risk could be taken of introducing the large bore engine at the beginning of "L" series instead of "M" With the introduction of this big bore engine will be introduced as the new type rear axle, i.e. hypoid, which has already been type tested, and the same type steering as for P.III. A programme of dates was asked for from the Experimental | ||