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).
Modifications to the bonnet and radiator design.
| Identifier | ExFiles\Box 66\3\ scan0147 | |
| Date | 1st January 1927 | |
| To DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} from R.Y c. to BJ. BY.{R.W. Bailey - Chief Engineer} X8260 RE. 40/50 BONNET. X.8260 X.8250 X.7260 X.8830 BJ's letter re. above does not quite agree with other comments. I take the case as I understand it. On 12-EX we make a bonnet slightly shorter - 1 3/8" - otherwise the bonnet is exactly like 8-EX W. series. We cannot believe anyone could detect this slight difference. I do not remember how it has come about, probably through economising some waste room. Anyway this combination sets the pedals forward, and gives more body room. If the objection is due to any increased width at the back of the bonnet (increased taper in plan) this is only the same as is so often demanded by coachbuilders, and supplied as special: it cannot well be avoided. I think however if there is any loss of appearance it may be due to the increased radiator thickness due to the integral shutters. But I believe it is like a new fashion, and as soon as we get used to it we may prefer it, as in so many changes since the level transmission. But a thick radiator may look heavy or dwarf the length of the body, so we might change this thickness and submit to Sales. If they do not mind slight, very slight, increase in the risk of boiling we should like to shorten the tubes somewhat and make the radiator lighter and less expensive, and more efficient for its size and weight. Suppose we took 1" off the tubes in length, and put the 1 3/8" back on the bonnet (waste) for appearance, and peace, if the alteration to the radiator only does not satisfy. We want the cleaner job of the integral shutters, and we rather prefer the extra water tank capacity. Personally I do not believe there is much in the case anyway which would make an order a year less, but from my point of view we have gained and lost appearance as follows :- SEE ORIGINAL FOR SKETCH. contd :- ELEVATION [Sketch of a tapered bonnet shape] MUCH TOP TAPER BAD. BONNET AND SCUTTLE SHOULD BE LOWER IN CENTRE. | ||