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).
The design of induction pipes and cylinder heads, discussing siamesed ports and comparing 4-port and 6-port arrangements.
| Identifier | ExFiles\Box 13\3\ 03-page010 | |
| Date | 17th January 1928 | |
| R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. to BJ. Hs.{Lord Ernest Hives - Chair} 47070 E4/M17.1.28. EAC.10 INDUCTION PIPE AND CYLINDER HEAD. X.7070 X.7050 X.4214 ----------------- When In Derby recently we had a discussion with Mr. Lovesey on the above and as a result asked him to report to you on the question of siamesed induction ports, which he has done in Hs{Lord Ernest Hives - Chair}/ACLL/LG13.1.28. The contention is as we well know that in the 4 port arrangement it is never possible to obtain test results in which the mixture strength of B. and C. are equal. SEE ORIGINAL FOR SKETCH. A.{Mr Adams} can be made equal to B. or to C. but never can all be made alike, at any rate while the mixture supplied is not in a gaseous form. Mr. Lovesey says that the Hispano with its 6 separate ports gives particularly good distribution under all conditions. The objection conceived to the 6 ports on EAC.10 was that the two middle ones were directly exposed to the long slot in the manifold as shewn in red onLec.2509 attached. We find however that on the Hispano pipe the two middle cyls. are nearly opposite the uptakes from the carbs, and apparently take no harm from it. A similar pipe is used on the big 6 cyl. Farman chassis. SEE ORIGINAL FOR SKETCH. This would suggest that we try our proposed form of induction pipe on the Hispano before finally deciding that we cannot have six ports on EAC.10. The bolting of the cyl. has to be distorted for the 4 port arrangement, but not for the 6. as can be seen from Lec.2509. The bolts could be left so that either system could be used without alteration to cyl. blocks or crankchamber. Regarding the question of the uptake we have not yet set this out to full scale, but we believe there is enough height between the carb. and the manifold to use the undertype slot as in fig.1 instead of the weir as in fig.2. with reduces the length of the individual branches to the cyls. a desirable feature. The length of the undertype slot is as in EAC.14. limited by the proximity of Nos. 3 and 4 sparking plugs. SEE ORIGINAL FOR SKETCH. contd :- | ||