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).
Proposal to introduce a new graded scheme for chassis power tests based on engine RPM.
| Identifier | ExFiles\Box 69\4\ scan0351 | |
| Date | 28th September 1927 | |
| RECEIVED X8771 Mx{John H Maddocks - Chief Proving Officer}1/T28.9.27 re Chassis Power Tests For some time past a minimum power curve of 3% below average has been worked to both on bench test and dynamometer. This at times necessitates a considerable amount of work being carried out to obtain passable power at high speeds, such as dismantling the head & grinding in the valves of an engine that will not pass test, which frequently gives us just sufficient power to pass of test. This we feel is unnecessary as a small difference in H.P. at high speeds has very little effect on road performance. The lower speeds do not give much trouble and slight differences in power at these lower speeds have more marked effects on road performance. We therefore propose to introduce a graded scheme of determining the minimum H.P. curve. At present the minimum curve is based on 3% less than average at all speeds. The proposed minimum curve would be based as follows:- R.P.M. 500. 750. 1000. 1250. 1500. 1750. 2000. 2250. 2500. 2750. % less than average. 2. 2½ 3 3½ 4 4½ 5 5 5 5 This we think will enable us to pass engines with less trouble without any detriment to road performance, in fact at the lower speeds the tendency will be to improve. If you agree to this proposal, we propose to put the scheme into operation immediately. | ||