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 engine modifications for the Phantom model, focusing on induction pipes, carburettors, and compression ratios.
| Identifier | WestWitteringFiles\P\July1926-September1926\ Scan083 | |
| Date | 30th August 1926 | |
| TO HS{Lord Ernest Hives - Chair}/ACL. FROM R.{Sir Henry Royce} Copy to BJ. RG.{Mr Rowledge} ORIGINAL (STAMP) PHANTOM INDUCTION PIPES ETC. Handwritten: X8070 XI XII I Handwritten (crossed out): X8050 X8080 RECEIVED (STAMP) 31 AUG 1926 (STAMP) We are very pleased with the progress you are making. Cold distribution is in all our engines extremely important. We think that an increased area of the slot into the manifold should be tried. It is very possible that it would be an advantage to even lengthen the 6" say 25%, and put up the width 25%, and also heat should be added so as to compare the pipes for power when heated. The investigations should be continued to find out how it is the MEP. is so low at all speeds in this engine. We had hoped from aero engine results to have obtained 100 MEP. at 2,500 RPM., and correspondingly greater MEP. at slower speed, rising to a maximum of say 125 at about 1,500 RPM., with about 4.5 compression ratio. In all cases Claudel and our own carburetters should be compared, and also grouping in three as well as six, for instance, the slot entrance to the induction pipe grouped in three, with two carburetters of smaller size might be passably convenient, both Claudel and RR. type. The compression ratio might be increased but this we should do in conjunction with the aluminium cylinder and head. The system of construction of liner and inserted valve seats has promised to be satisfactory in E.16. It is now to find whether the improved shape of the head and turbulence are advantages, and we would also like to know if there is any hope of getting any more power by altering the cams to the most recent form adopted for F.10., where the overlap is increased by making the exhaust cam longer, the angle between the cams being 108°. Confirm by getting a hotwater jacketed pipe on the road: it may give better consumption also. Simple ordinary hot water should be all that is needed for so good a pipe. R.{Sir Henry Royce} | ||