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).
Experiments and modifications made to increase the power output of the 'China' engine.
| Identifier | ExFiles\Box 5a\5\ 05-page215 | |
| Date | 11th August 1923 | |
| To R.{Sir Henry Royce} from HA/ACL. c.c. SG.{Arthur F. Sidgreaves - MD} c.c. HGT. E.{Mr Elliott - Chief Engineer} c.c. DA.{Bernard Day - Chassis Design} RV. Handwritten: X 5771. Hs{Lord Ernest Hives - Chair}/ACLA/AUG.11.23. Handwritten: X5770 (crossed out) X5771 For sketch See Original "CHINA" ENGINE - FACTORS WHICH HAVE INCREASED THE POWER OUTPUT. We have continued the power increasing experiments on the large bore 'China' engine and are now able to show to what extent some of the various factors contribute to the total power gain. We have now obtained 85 B.H.P. at a speed of 3200 R.P.M. using the following modifications :- (1) Large valves & ports as stated in our previous report. (2) 5.24/1 compression ratio. The same as in 16-34 at W.W. (3) Camshaft E.55352.116° (4) Larger diameter induction pipe with a Zenith horizontal carburetter attached to it instead of using the passage through the cylinder block (see sketch) All the above factors therefore, represent an increase of 28.5 B.H.P. or 50% over the standard China engine. The Zenith carburetter gives very low induction pipe depressions and consequently assists the other factors in giving their maximum results. It is hardly an instrument that would be acceptable for road use because due to its | ||