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 considerations for a supercharger, engine position, clutch pit, and fan.
| Identifier | ExFiles\Box 3\4\ 04-page072 | |
| Date | 7th July 1932 guessed | |
| (2) (6) Regarding the supercharger I had thought that the Powerplus was particularly liable to be damaged by backfires, and I am intensely relieved to hear that this is an unknown trouble with this type. I hope it is true because we are relying upon it, otherwise we might have to adopt either the Roots type, or the system of blowing into the carburetter, both of which we are now ill-prepared to do. (7) Regarding the exact position of the engine, 'Camacna' tell us that we must stop pushing it forward of the cross steering tube. This seems to be usual in all our cars. We have therefore adopted 8". (8) We are also lengthening the clutch pit slightly so as to make the Change speed lever a little more practical as we do not want to put the tower quite so far forward. The drawings for the gearbox are well advanced and we hope to send you most of it this week. (9) With regard to the fan, it would seem that we must embody this, but it would not be run in competitions, so that the belt should be easy to remove. Owing to the Vee radiator the fan will be rather far back, with the belt between the fan and radiator. We are burning our boats to the above arrangements, but have asked E.{Mr Elliott - Chief Engineer} to investigate as to whether we can still use a Roots type blower should the Powerplus be disappointing. He thinks we could do so by making the blower rather neater than the standard design, and running it rather faster than engine speed. We imagine that the Roots type might prove less liable to be damaged by backfires, and we quite think it is capable of running at higher revs for a given size than the Powerplus. R.{Sir Henry Royce} | ||