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 and specifications for the exhaust system and side steering tube springs.
| Identifier | ExFiles\Box 3\4\ 04-page408 | |
| Date | 17th July 1933 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Em. c. to Ev.{Ivan Evernden - coachwork} c. to Sft.{Mr Swift} Hs{Lord Ernest Hives - Chair}/Em.S/KT.17.7.33. With reference to EY.11/C.14.7.33. The following is the latest information we can give you with regard to the four points raised. (1) Exhaust System. We have done the best we can with the fishtail under the rear axle, and in order to get the necessary silence we have been forced to baffle the rear expansion box as shown in the attached sketch. The power loss is increased by approx. 2 HP. over the other scheme. Since we have a cut-out we think we shall have to tolerate this. (2) Side Steering Tube Springs. The side steering tube springs we are running in France are as follows :- Wire .212 dia. 5 working coils with 3/4 coil ground square each end. Total coils 6½. Mean diameter .728" Rating 1:70 lbs/in. Free length 1.955 ±.005 Normal length in position 1.900 These will replace the existing springs F.100162 except that the spigots for the inside diameter must be slightly reduced. The length of the collars each end must be increased so as to reduce the possible deflection from the figure of .287 of HH.Sch.164 to .150 It is possible that the poundage may be found to require modification as a result of the 10,000 miles test, but we feel certain that they will be more satisfactory than those we are at present fitting. The most unpleasant feature of the original side steering tube spring is its tendency to promote slow speed wobbles owing to its excessive flexibility. (3) We think that the common petrol drain for the carburetter and air silencer is very satisfactory. | ||