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).
Potential modifications to the back axle, induction pipe, and gear ratios to improve road holding and petrol economy.
| Identifier | ExFiles\Box 181\M8\ img031 | |
| Date | 11th May 1917 | |
| E6/B11.5.17. Contd. -2- switch was drawn out by Mr. Olley and sent to Derby a long time ago. It would be as well if Mr. Olley saw it while he is there. X.2651. I cannot believe it is impossible to do anything in the way of lightening the back axle, and I do hope you will be able to manage some modification to this part with the object of getting the car to keep the road although it is only lightly loaded behind. I do not wish this work to interfere with the current aero work, but if it is intended to get this car right I feel that some progress should continually be made towards this end. X.2039P. The induction pipe experiments to give better distribution and ramming could be fitted, even if the camshaft was not fitted. I have the impression that for decent petrol economy it will be advisable to use a higher geared back axle, and it would be excellent to find out the exact difference made by using one of our earlier gear ratios. I daresay we have bevels wheels in stock that could be fitted. It would be quite reasonable to use such a higher gear if we could get better mean pressures at both slow and higher speeds, in fact it appears that if we want petrol economy we shall have to be contented with less cubic inches of piston displacement per ton mile. I believe that the very high piston displacement in the case of the Packard X.435 is one of the reasons for its extremely bad consumption. R.{Sir Henry Royce} | ||