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).
Tests comparing a single carburetter with a two-branch induction pipe against a dual carburetter system on a 'Japan' engine.
| Identifier | ExFiles\Box 5\4\ 04-page228 | |
| Date | 28th December 1929 | |
| TO L. From HA/ACL. C. to AL. HGR. C. to L. DA.{Bernard Day - Chassis Design} C. to EV.{Ivan Evernden - coachwork} Y5080 HA/ACL.1/WJ.28.12.29. "JAPAN" INDUCTION SYSTEM. TESTS WITH TWIN RANGING PIPE & SINGLE CARBURETTER. Y5070 Y5080 Y3605 Y4660 We have now completed some tests on the test bed with a two branch induction pipe using one carburetter on a 'Japan' engine as requested in RS{Sir Henry Royce's Secretary}/M25.11.29. It has always been our experience that two carburetters, each supplying three cylinders through independent induction pipes, gave a better power curve for our work than a single carburetter and the object of the above experiment was to see if a similar characteristic could be obtained with one carburetter used with a two branch induction pipe. For the experiment a pipe was made up in copper, as shown on appended print. The branch connecting the two three cylinder manifolds with the single Stromberg carburetter was detachable so that we could use two separate carburetters for comparison. The power curves obtained with each system are shown on attached print. We see that although there is a little difference in the max. power reached in each case, there is an appreciable advantage given by the twin carburetters at lower speeds. Unfortunately, the metering with the two manifolds was bad below 1725 R.P.M. so we did not continue the curve below that point. These carburetters had no mixture control and we could not get a jet which would satisfy the whole curve. | ||