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).
Performance tests on a cast iron high power engine unit compared to the standard Wraith.
| Identifier | ExFiles\Box 108\3\ scan0097 | |
| Date | 28th April 1939 | |
| 600c, 10HH + 1320 SECRET. Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Hs.{Lord Ernest Hives - Chair} c. Ey. c. Da.{Bernard Day - Chassis Design} c. RHC.{R. H. Coverley - Production Engineer} c. EX. c. HPS.{Horace Percy Smith - Experimental Factory Mgr} c. Bm/Ev.{Ivan Evernden - coachwork} c. De/Jnr.{Charles L. Jenner} Bm14/H.28.4.39. Cast Iron High Power Engine Unit. A further series of tests on the high power cast iron unit was carried out last week. In this case, the cast iron unit was given a free induction and exhaust system so that the full power output permitted by the new design could be obtained. The attached report indicates the results achieved. Briefly with this engine unit, the car lapped @ 82.1 m.p.h. against the 75.46 m.p.h. achieved by the standard Wraith, a gain of 6.7 m.p.h. In spite of the increased horse-power obviously developed in order to produce this increase in speed, the oil temperature was only slightly greater than that of the standard car. It will be seen that the increase in speed was not obtained at the expense of acceleration, the gain from 10 to 70 miles being 6.6 secs. The fact that this engine has now had a good thrashing on the track and road without developing any serious trouble is encouraging. The fact that we can get this increased performance out of the new engine does not mean that we propose to use it on Rolls-Royce cars. It does indicate, however, that wherever the C.I. high power unit replaces the standard unit we shall expect to get a slight improvement in performance without sacrificing silence or smoothness. We hope, however, that the test in France will indicate that we shall not have to sacrifice durability. S.E.50, the next car to go to France will be fitted with a unit similar to that which did the tests in 29.G.VI. Rm.{William Robotham - Chief Engineer} | ||