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 revised bonnet and dash on the Phantom II model.
| Identifier | WestWitteringFiles\U\2January1930-September1930\ Scan025 | |
| Date | 10th February 1930 | |
| ORIGINAL TO SG.{Arthur F. Sidgreaves - MD} FROM EV.{Ivan Evernden - coachwork} COPY TO W. HS.{Lord Ernest Hives - Chair} RE REVISED BONNET AND DASH. PHANTOM 2. We agree that the Segrave bonnet and dash were not a success. We thought that the radiator with the shallowed top tank was an improvement. With reference to your suggestion that we should look at a radiator with sloping sides to suit the taper of the bonnet, we suggest that that particular issue might be made subsequent to our perfecting the proposed bonnet with the raised side hinge, for the following reasons:- (1) The tapered radiator is much more expensive to make (2) It calls for an entirely different design and construction. (3) It is much heavier, as the sides have to be bronze castings. (4) Mr. Royce, not long before he left was in favour of changing to the paralell sides radiator on the 20/25HP. for these reasons. (5) It is not so very long ago we made a tapered sided radiator for a "W" Series P.I. and when it was seen it was disliked. We do not wish this to mean that we are not in sympathy with the suggestion, but we would like to keep it a separate issue as it is a design issue and would hold up considerably the main issue, namely, the standardisation of a bonnet with a raised side hinge. It would be as well to make it quite clear why we are so badly in need of this feature. In fact we venture to suggest that it may not be realised that this problem is the same as that of building low looking cars on our chassis which have ample headroom. The height of the rear seat-board on Phantom 2. from the ground is the same as on Phantom I. The level top of the frame, and the bonnet and radiator are 1.000. lower on P.2. than on P1. Nearly all the cars we build today have a waist-line which is a continuation of the side bonnet hinge. Therefore, since the roof is no lower on P2. than on P1. it follows that the height of the head above the waist line of a body on P.2. must be 1.000.ins. greater than that of a similar body on P.I. To counteract this, coachbuilders are cutting down the headroom by 1.000.ins. and so cramping the rear seats. Secondly, we have always been inferior in this respect to many other people due to the shape of our radiator top tank, which forces the side hinge of the bonnet to be at a much greater depth below the top of the bonnet than is the light line on such cars as Daimler, Issotta, Hispano. Thirdly, our rear upsweep of the frame is greater than that of our competitors due to our flexible springing. Handwritten notes: x725? x7260. x7500. x7830. | ||